A plain-English dictionary of BIM terms - every acronym, standard, and Revit concept in one searchable glossary. If everyone around you is throwing around acronyms like BEP, LOD, CDE, and IFC like they're basic vocabulary, you're in the right place: 687 terms, from foundational concepts to the full BIM dimension stack, cross-linked between related ideas. ← Articles
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Geometry
Model + intelligent 3D geometry (the base layer). BIM "dimensions" describe what layer of information is added on top of the 3D model. Think of 3D as the base - each additional dimension enriches the model with a new type of data.
The base model. Walls, floors, roofs, columns, ducts, pipes - all modeled as intelligent 3D objects in space. This is what most people think of when they hear "Revit model."
The BIM dimension stack (3D–10D)
Autodesk 3ds Max
Autodesk's long-established 3D modeling, animation, and rendering software, still widely used for high-end architectural visualization. Where Enscape or Twinmotion prioritize speed and live interactivity, 3ds Max is usually the choice when a project needs the extra control and polish of a fully offline-rendered still.
Time
Model + construction schedule. The model linked to a construction schedule. Each element is tied to a task and a date, so you can animate the building sequence, catch scheduling conflicts before breaking ground, and communicate the build plan to all stakeholders visually.
Cost
Model + cost data. The model linked to cost data. Quantities are extracted directly from modeled elements and multiplied by unit rates, giving real-time budget tracking as the design evolves. Changes to the model automatically update the cost estimate.
Sustainability
Model + energy & environmental analysis. The model used for energy and environmental analysis. 6D BIM evaluates daylight levels, heating and cooling loads, carbon footprint, and lifecycle environmental impact - all from early design stages, when changes are still cheap to make.
Facility Management
Model + operational asset data. The model handed over to building operators after construction. Asset data - equipment specs, warranty periods, maintenance schedules, replacement cycles - is embedded in the model and used by the facility management team throughout the building's operational life.
Safety
Model + site safety planning. Safety information integrated into the model. 8D BIM identifies construction site hazards, simulates risk scenarios, and embeds safety procedures into the building sequence. It helps contractors plan safer sites before anyone sets foot on them.
Lean Construction
Model + workflow optimization and waste reduction. The model used to optimize workflows and reduce waste. 9D BIM applies lean construction principles - minimizing idle time, sequencing work efficiently, reducing material waste - and feeds those improvements back into the construction plan.
Industrialization & Digital Twins
Model + prefabrication data feeding a live Digital Twin. The most advanced dimension. 10D BIM integrates prefabrication and modular construction data (off-site manufacturing tolerances, delivery logistics, assembly sequences) and feeds into a Digital Twin - a live virtual replica of the building that continues to receive real-world data from sensors long after construction is complete.
Note: 3D through 7D are widely adopted and standardized. 8D–10D are increasingly used but not yet uniformly defined across all standards bodies.
Autodesk Construction Cloud
Autodesk's umbrella construction-management platform - the modern name for what BIM 360 grew into, bundling document management, model coordination, and field tools together. ACC brings Autodesk Docs, Model Coordination, Design Collaboration, Build (site issue tracking), and other modules under one account and one set of project permissions, replacing what used to be several more loosely connected BIM 360 products. Most references to "BIM 360" on a current project actually mean ACC today. In March 2026 ACC itself was renamed Autodesk Forma, so "ACC" and "Forma" now point at the same platform.
A construction project information management platform for document control, correspondence, and workflow approvals, widely used internationally including across the Middle East. Aconex fills a similar role to Newforma or Procore's document-control side - a single, auditable record of every drawing revision, submittal, and approval on a project - but has particularly strong adoption on large international infrastructure and mega-projects outside North America.
Designing a building's construction and layout to control sound - blocking noise between spaces and managing how sound behaves within a single room. Acoustic design covers two related but distinct problems: sound insulation (how much noise passes between rooms, floors, or to the outside) and room acoustics (how sound behaves once it's inside a space - reverberation, echo, speech clarity). Wall and floor compound structures, party-wall separation details, and finish selections all get checked against acoustic performance targets set out in local building regulations.
A family that reshapes itself to fit points defined by a pattern, curve, or surface. A special family type whose placement points are not fixed - they adapt to conform to a host, like a divided surface, a curved curtain wall panel grid, or a path defined by a Dynamo graph. Instead of one rigid shape, an Adaptive Component flexes its geometry to fit wherever its points land, which is what makes complex, non-repetitive facade panels or canopy structures possible without manually modeling each unique piece.
They are the standard technique for panelizing a curved or freeform surface: place one adaptive family, apply it across a whole divided surface, and each instance automatically reshapes to fit its own unique panel location.
A third-party or custom plugin that extends Revit's built-in functionality - the general category Dynamo, pyRevit, and Ideate BIMLink all belong to. Some add-ins run through the Revit API directly and require real programming; others, like Dynamo, offer a visual layer on top of that same API so non-programmers can automate tasks too.
A fast, statutory dispute-resolution process in UK construction law, giving parties a binding decision within weeks rather than the months or years a court case would take. It exists specifically because construction disputes can't wait years to resolve without stalling an entire project - a decision is binding immediately, even if either side can still challenge it later through arbitration or litigation.
A security instrument protecting a client's upfront payment to a contractor if the contractor then defaults. An Advance Payment Bond protects a client who pays a contractor money upfront - for mobilization or long-lead materials - guaranteeing that sum is refunded if the contractor then defaults before delivering the corresponding work. It covers a different risk than a Performance Bond or Retention Bond, which protect against poor-quality or incomplete work rather than an unearned early payment.
Architecture, Engineering, and Construction
The umbrella industry combining architecture, engineering, and construction - the sector BIM tools like Revit are built to serve. AEC (Architecture, Engineering, and Construction) is the umbrella term for the industry that plans, designs, and builds the built environment - three disciplines that traditionally worked from separate drawings and handed work off between silos. BIM exists largely to fix that: a shared, coordinated model lets architects, structural and MEP engineers, and contractors work from the same source of truth instead of reconciling conflicting sets of documents after the fact. When an article or tool on this site says "the AEC industry," it means this combined sector, not any one discipline alone.
Approved For Construction Drawings
Drawing set formally approved and released for building on site. The final status a drawing reaches once the design team, and often the client or approving authority, has signed off on it - work can now legally start on site from that revision. AFC is the last stop in a drawing's CDE status lifecycle (Work in Progress, Shared, Published/AFC), and any change after this point requires a formal revision, not a quiet edit.
Confusingly, some firms use AFC and IFC Drawings almost interchangeably; others draw a sharper line - IFC marks the moment drawings are issued to the site team, while AFC confirms they have been formally approved, which may happen slightly earlier or later depending on the project's issue tracking workflow. Either way, once a drawing set is superseded by a newer AFC revision, the old one should be clearly marked void to avoid the classic, and expensive, mistake of a contractor building from an outdated sheet.
AIA Document A201 - General Conditions of the Contract for Construction
The most widely used general conditions document in the AIA family of standard US construction contracts. Where the broader "AIA Contract Documents" entry covers the whole family, A201 is the specific one most US construction professionals actually mean when they just say "the AIA general conditions."
American Institute of Architects Contract Documents
A widely used family of standard US construction contract forms (like the A201 General Conditions), the American counterpart to the UK's RIBA/JCT and international FIDIC contract families. AIA's E203/G202 documents specifically govern BIM and digital data protocols on US projects, playing a similar role to a BEP in an ISO 19650 project - defining model authorship, LOD expectations, and data ownership within the broader AIA contract framework.
Asset Information Model
The information model used to operate the building. The AIM is the information model used to operate and maintain the building after handover: asset registers, equipment data, maintenance schedules, warranties, and as-built models. If the PIM answers "how do we build it?", the AIM answers "how do we run it?" - and COBie is one of the common vehicles for moving data from one to the other.
Asset Information Requirements
The owner's information needs for operating the finished asset. Where the EIR defines what information a client needs during design and construction, the AIR defines what information the client needs to operate the building once it is handed over - maintenance schedules, warranty data, equipment manuals, spare-parts lists. The AIR feeds directly into the AIM: it is essentially the specification for what the Asset Information Model must contain. A well-written AIR early in a project makes the eventual handover to facilities management dramatically smoother, because everyone knows from day one exactly what data needs to be collected.
A basic Revit tool that lines one element up exactly with a reference - another element's edge, a grid line, a level - with a single click. Locking an alignment after using it keeps the two elements tied together going forward - move the reference later, and the aligned element follows it automatically.
Nemetschek's BIM authoring platform, widely used in continental Europe for both architectural and precast/structural design. It sits in the same Nemetschek family as Vectorworks, another data point in how fragmented the BIM authoring market actually is once you look past the Revit-centric English-speaking market.
A Revit family category that lives only in 2D views - tags, symbols, title blocks - and never appears as 3D geometry in the model. It's the counterpart to a model family: a door tag, a level head, and a north-point symbol are all annotation families, scaling with the view rather than existing at real-world size in 3D space.
The ISO 19650 role for the client or organization commissioning the work. One of ISO 19650's defined roles: the Appointing Party is the organization commissioning the work - usually the client - responsible for setting the EIR and ultimately deciding what information it needs. Every other role in the standard's terminology is defined relative to this one: the Appointing Party appoints a Lead Appointed Party, who in turn may appoint further Task Teams.
Knowing these role names matters mainly when reading an ISO 19650-compliant contract or BEP directly - the standard uses them precisely and consistently, and the terminology can otherwise read as needlessly formal for what is, in plain language, simply "the client."'
Structure
The UK Building Regulations document covering structural safety - a building's ability to safely carry the loads it's designed for without collapse or excessive movement. Approved Document A works alongside the structural Eurocodes rather than replacing them - it sets the regulatory baseline while the Eurocodes provide the actual engineering calculation methods a structural engineer uses to demonstrate compliance. Structural columns, framing, and foundations modeled in Revit ultimately need to satisfy the load paths and safety factors this document requires.
Approved Document B: Fire Safety (UK Building Regulations)
The UK's official fire-safety design guidance - covering escape routes, fire-resistance ratings, and compartmentation - that a building's Revit model needs to demonstrate compliance with. Fire-rating parameters on Revit wall and door families, travel-distance checks on escape routes, and compartment boundaries on plans all exist specifically to demonstrate Approved Document B compliance - it's one of the most common reasons a design gets sent back for revision late in a project.
Site preparation and resistance to contaminants and moisture
The UK Building Regulations guidance covering ground preparation, contamination, and moisture resistance. Approved Document C covers site preparation before building starts - dealing with contaminated ground, unstable ground, and moisture resistance for the finished structure. It's the Approved Document most directly informed by a project's Ground Investigation Report, since the site conditions that report uncovers drive which C-compliant measures the design needs.
Resistance to Sound
The UK Building Regulations document setting minimum sound-insulation performance between dwellings, and acoustic standards for schools and other building types. Approved Document E sets minimum airborne and impact sound insulation values for party walls and floors between separate dwellings, along with pre-completion testing requirements to prove a building actually meets them on site, not just on paper. It's the regulatory anchor most acoustic design work on residential projects is checked against.
Approved Document F - Ventilation
Part F of the UK Building Regulations, setting ventilation requirements to protect indoor air quality and prevent condensation and damp. As buildings are built increasingly airtight to meet Part L's energy targets, Part F's ventilation requirements become the counterbalance that keeps them healthy to actually live in.
Protection from falling, collision and impact
The UK Building Regulations guidance on stair, ramp, guarding, and glazing safety to prevent falls and collisions. Approved Document K covers protection from falling, collision, and impact - stair and ramp geometry, guarding heights, and glazing that could be mistaken for an opening - directly governing how Revit's Stair, Ramp, and Railing families need to be dimensioned to comply.
Approved Document L - Conservation of fuel and power
Part L of the UK Building Regulations, covering a building's energy efficiency and carbon emissions - the energy-focused counterpart to Approved Document B's fire safety rules. It's the regulatory floor a project's operational carbon and net-zero ambitions get measured against - meeting Part L is the legal minimum, and many projects now set their own targets well beyond it.
Approved Document M - Access to and use of buildings
Part M of the UK Building Regulations, covering accessibility - step-free access, door widths, accessible sanitary facilities. It sits alongside Approved Documents B and L as one of the three most frequently checked parts of the regulations on almost any building project.
Autodesk Platform Services (formerly Forge)
Autodesk's cloud API platform for building custom apps on top of BIM data. Autodesk's suite of cloud APIs - formerly branded Forge, renamed Autodesk Platform Services - that lets developers build custom applications on top of BIM data without needing Revit installed: viewing models in a browser, automating model checks, extracting data at scale, or connecting a project's BIM data into a company's own internal software.
Where Dynamo automates inside one open Revit session, APS operates at a platform level - server-side, cloud-hosted, capable of processing many projects' models without a person sitting at a desktop. It is the layer that custom, in-house BIM tooling and larger construction-tech products are typically built on.
A private, binding dispute-resolution process where an independent arbitrator (rather than a court) decides the outcome. Where adjudication is fast and interim, arbitration is slower but final - many international construction contracts, including FIDIC, specify arbitration as the ultimate route if earlier dispute mechanisms fail.
Esri's GIS platform, the industry-standard tool for mapping, analyzing, and managing geographic and infrastructure data at city and regional scale. It's the tool most commonly sitting on the GIS side of GIS-BIM integration, receiving federated model data exported or streamed from the Autodesk/Bentley side.
Graphisoft's BIM authoring platform for architecture, one of the longest-established alternatives to Revit and especially widely used in Europe. It shares the same object-based-modeling philosophy as Revit but comes from an entirely separate lineage - Teamwork is its own worksharing system, and IFC is usually the practical bridge when an ArchiCAD-based architect coordinates with a Revit-based engineer.
A mobile app for site inspection reports, punch lists, and photo-based observations. ArchiSnapper is a mobile app for generating site inspection reports on the spot - photos, annotations, and punch-list items compiled into a shareable PDF report directly from a phone, aimed at architects and site inspectors rather than the broader field-management scope of tools like Fieldwire.
A Revit view type that calculates and displays gross, net, or rentable area boundaries - distinct from a room plan, which is built from individual room elements instead. Where room-vs-space usually comes up in the context of MEP coordination, area plans serve a different purpose entirely - gross floor area and rentable area calculations for planning approval or leasing, drawn with their own area boundary lines rather than room tags.
A Revit ruleset defining how an area calculation - Gross, Rentable, Usable - is measured across a project. An Area Scheme defines the measurement rules behind an Area Plan - whether boundaries are drawn to the wall centerline, the interior face, or a leasing convention like BOMA - so a project can maintain several distinct area calculations (Gross Building, Rentable, Usable) side by side without them interfering with each other.
A Revit tool that duplicates an element multiple times in a straight line or a radial pattern, at an evenly spaced or fixed interval. A row of evenly spaced parking bollards or a radial pattern of columns around a curved building are the kind of repetitive layouts Array handles in seconds instead of placing each one by hand.
As Built Model
The model of what was actually built. The model that reflects what was actually built - not what was designed. Construction always brings changes: a pipe route moves, a beam is raised, a wall shifts. The as-built model captures all of them, often verified against laser scans of the finished building (Scan to BIM).
It is the basis for the AIM and facility management - you cannot maintain a building from a model that does not tell the truth.
As Designed Model
The design intent model - what was planned, before construction reality intervenes. The third point in the design-to-construction trio, alongside As Made and As Built. The As Designed model is the design team's original intent - what should be built, based on the design decisions made before construction started. It is the baseline everything else gets measured against: As Made captures what was actually installed on site, As Built is the coordinated record of the completed building, and the gap between As Designed and As Built is, in effect, a map of every change that happened during construction.
Keeping the As Designed model intact, rather than overwriting it with site changes, matters for exactly this reason - without it, there is no way to see how much the finished building actually diverged from the original plan.
The state of a building element exactly as it was manufactured off-site, before installation - critical for prefabricated and modular construction. In DfMA and modular construction, elements are built in a factory to precise tolerances before ever reaching site - "as fabricated" captures that manufactured state, which can then be compared against both the design intent and, later, the as-installed reality to catch discrepancies early, while they're still cheap to fix.
As Made Model
A verified, granular record of exactly what was installed on site. A record - often at component or connection level - of exactly what was installed or constructed on site, usually captured by the installing team directly from site measurements or scans. As-Made data is typically more granular and immediate than an As-Built model: it is produced discipline-by-discipline as work happens, before it gets consolidated.
The as-made record then feeds into the broader As-Built model - the design team updates the design-intent model with the as-made data (plus any further verification) to produce the single coordinated record of the completed building. In short: As-Made is the raw site truth; As-Built is the coordinated model built from it.
As-Occupied Model
The state of a building after tenants move in and make their own changes. The As Occupied state captures a building after tenants and operators actually move in and start changing things - rearranging partitions, adding equipment, modifying finishes - changes that happen entirely outside the original project team's control or awareness. Keeping an As Occupied record current is genuinely hard, which is exactly why it matters: an AIM that was accurate on handover day slowly drifts from reality as occupants make their own changes, and a facilities team working from a stale model is planning maintenance and renovations against a building that no longer quite exists.
The model or schedule representing how a project was intended to be built, before any site changes or deviations occurred. "As planned" is the baseline everyone measures against - construction progress, schedule slippage (4D BIM), and eventual as-built deviations are all compared back to this original plan. It sits alongside as-designed, as-made, as-built, and as-occupied as one of the recognized project-state terms.
Checking a completed as-built model against the real, physical building - usually via a laser scan or photogrammetry survey - to confirm the model actually matches what was constructed. It's the quality-control step behind the whole scan-to-BIM and as-built process: a point cloud is overlaid on the as-built model, and any deviation beyond an agreed tolerance gets flagged before the model is signed off and handed over.
The condition of a building or site exactly as it stands today, before any proposed work - the baseline every retrofit or refurbishment design is measured against. It sits at the start of the as-* family, before as-designed even begins - a condition survey or a scan-to-BIM model is usually how an as-existing state actually gets captured and modeled.
The formally released, approved version of a piece of information at a specific point in time - as opposed to a draft still in review. A CDE's status workflow exists precisely to separate work-in-progress from as-issued information - only the second one is safe for another party to actually rely on and build from.
The state of an asset's information after it accounts for every repair, replacement, and maintenance intervention carried out since handover - not just what was originally built. An as-built model freezes the moment of handover; an as-maintained record keeps moving after it, capturing the boiler swapped in year three or the roof re-covered in year eight - exactly what an FM team needs to trust the AIM years later.
A record of the location and condition of every known asbestos-containing material in an existing building, required before any refurbishment or demolition work. On a retrofit project it's checked before the first wall is even opened - missing or out-of-date entries are one of the most common causes of a construction-phase health-and-safety stoppage.
American Society of Heating, Refrigerating and Air-Conditioning Engineers
A professional body whose standards define HVAC design requirements, energy performance benchmarks, and ventilation rates referenced throughout MEP modeling and building performance simulation. ASHRAE 90.1 (energy efficiency) and ASHRAE 62.1 (ventilation) are the two standards MEP engineers reference constantly when sizing systems in Revit - building performance simulation tools check a design against these same benchmarks long before a mechanical system is ever fully modeled.
An Autodesk Construction Cloud tool that organizes and reports on model data - most commonly for real-time quantity takeoffs and condition-based data grouping. Instead of exporting a static schedule out of Revit, an estimator can connect Assemble directly to the live model and slice quantities by any condition needed for a specific bid package - a faster, more flexible layer on top of the same underlying model data Revit's own schedules use.
A Revit feature that packages a set of selected elements into a single unit with its own dedicated views and sheets, distinct from a Group's simple copy-and-place behavior. A precast concrete panel or a prefabricated bathroom pod is a natural fit for an Assembly - it needs its own detail views and a shop-drawing-style sheet for the fabricator, which is exactly what an Assembly generates automatically, unlike a plain Group which has no view/sheet infrastructure of its own.
A Uniformat-based classification code assigned to a Revit element, identifying which building system or assembly it belongs to. It's the field that lets a schedule roll up quantities by building system - all exterior wall assemblies together, say - rather than only by Revit's own built-in category.
A standardized score describing the current physical condition of an asset - good, fair, poor - used to prioritize maintenance and capital investment. A condition survey is the one-off assessment that produces it; the rating itself is what actually feeds a facilities management team's decision about which roof to replace this year versus which one can wait.
Formally taking an asset out of active service at the end of its working life, including updating the asset register and AIM to reflect it. It's the formal bookend to an asset's lifecycle - without it, a decommissioned boiler can keep sitting in the asset register as if it's still something facilities management needs to maintain.
The ongoing, whole-lifecycle discipline of operating and maintaining a physical asset. The broader discipline that BIM's 7D and AIM exist to support: the ongoing, whole-lifecycle work of operating, maintaining, and eventually replacing a building's systems and components, long after construction ends. Asset management thinks in decades, not project milestones - maintenance schedules, replacement cycles, energy performance, compliance inspections, all tracked against the actual physical assets a facilities team is responsible for.
Where BIM traditionally focused on getting a building built, the growing overlap between BIM and asset management (through the AIM and standards like ISO 19650's part 3) is what turns a one-time model into a long-term operational tool instead of a file that gets archived the day the building opens.
The owner's document setting out how a built asset will be operated, maintained, and eventually renewed or disposed of over its working life. Where an EIR and AIM are about the information a building carries, the asset management plan is about the decisions that information is meant to support - when to replace a plant item, how to budget for lifecycle costs, which parts of the estate to invest in next. ISO 55000 sets the international standard it's usually built against.
A master list of every physical asset in a building or portfolio, each with a unique identifier, linked to its data in the AIM. It's the practical spine an FM system runs on - every work order, maintenance schedule, and asset-tagging effort ultimately points back to a single row in the asset register.
Attaching a physical identifier (QR code, barcode, or RFID chip) to a real piece of equipment so it can be scanned on site and matched to its record in the BIM/FM data. A facilities manager scanning a tag on a rooftop air handling unit should land directly on that exact asset's model data - warranty status, maintenance history, spec sheet - closing the gap between the physical building and its digital record that a handover package alone doesn't solve.
Revit's deep file-health check that finds and repairs low-level model corruption. A deeper, slower file-health check than Purge - Revit's Audit command scans the entire project database for low-level corruption and inconsistencies that build up over long project lifespans, especially in heavily workshared models, and repairs what it can. It is typically run when a file starts behaving strangely (unexplained crashes, elements that won't delete cleanly) or as periodic preventative maintenance on large, long-running projects.
Audit and Purge solve different problems - Purge removes unused content, Audit repairs unhealthy file structure - and a well-maintained large project usually runs both on a regular schedule rather than waiting for something to visibly break.
Autodesk's original 2D/3D drafting software - the industry standard for decades before BIM, and still the tool most Revit newcomers are transitioning from. The core mental shift moving from AutoCAD to Revit is that CAD draws independent lines representing a wall, while Revit models an actual parametric wall object that generates those lines (and every schedule, section, and quantity) automatically - which is why "AutoCAD habits" like manually drafting details from scratch are the most common source of friction for new Revit users.
Autodesk Construction Cloud's field-management module, covering site quality, safety, and progress tracking - the modern successor to BIM 360 Field and PlanGrid. It's where issue tracking and progress monitoring actually happen day to day on site - the tablet app a site manager opens, not the design coordination BIM 360 was originally known for.
The document-management module inside Autodesk Construction Cloud - the shared, permission-controlled home for a project's drawings, models, and files. Autodesk Docs is where a project's official document set actually lives - version history, approval workflows, and folder-level permissions all sit on top of it, functioning as the project's CDE. Revit's Cloud Worksharing and published sheets both connect directly into it, alongside issue tracking and coordination tools that reference the same underlying files. As of March 2026 Autodesk Docs is called Forma Data Management, following the rename of ACC to Autodesk Forma. The module and its behaviour are unchanged.
Autodesk's cloud platform for early-stage design analysis and project data/document management - the current name for what was previously Autodesk Construction Cloud's design collaboration and document-management tools. Forma combines fast, cloud-based environmental and massing analysis (sun, wind, noise) for early design decisions with the document management, file transmittal, and issue-tracking modules that used to sit under the BIM 360/ACC name - Revit connects to it directly for cloud model sharing and coordination. Since March 2026 "Forma" is also the new name of Autodesk Construction Cloud (ACC): the former Autodesk Docs is now Forma Data Management, and BIM Collaborate Pro is Forma Design Collaboration. The early-stage site tool is now called Forma Site Design.
Autodesk's public status page showing the real-time operational health of its cloud services - Revit Cloud Worksharing, ACC, BIM 360, and more - plus incident history and uptime. Check health.autodesk.com the moment cloud worksharing, sync, or an ACC upload suddenly stops behaving - it is usually the fastest way to tell whether the problem is on your end or Autodesk's before spending an hour troubleshooting locally. The dashboard tracks status for well over a hundred individual services, so it is worth searching for the specific one you use (Revit Cloud Worksharing, BIM 360 Docs, APS) rather than reading through the whole list.
Autodesk's cloud-based building performance analysis tool, connected directly to Revit, for early energy, solar, and lighting studies. Insight pulls geometry and location data straight out of the Revit model to run whole-building energy analysis without needing a separate dedicated simulation model - useful for the quick, iterative "what if we changed the window ratio" questions that come up constantly in early design.
An Autodesk Construction Cloud tool for measuring quantities directly from 2D drawings or 3D models. Autodesk Takeoff is part of Autodesk Construction Cloud, used by estimators to measure areas, lengths, and counts directly from 2D drawings or a linked 3D model for pricing, without leaving the same platform the project's documents already live in.
A frozen, dated snapshot of a model kept as a fixed reference point, so later changes can be measured and compared against it. A cost baseline set at design freeze is what every later change order gets measured against - without it, "how much did this project actually grow" has no fixed starting point to answer from.
A document recording the assumptions, criteria, and standards an engineering design is built on. A Basis of Design (BoD) records the assumptions, design criteria, and codes an engineering design relies on - occupancy loads, environmental conditions, applicable standards - so anyone reviewing the design later understands why it was sized and configured the way it was, not just what the final numbers are.
BIM Collaboration Format
Open format for sending model issues between tools. The open format for exchanging model issues - not the model itself. A BCF file carries a comment, a screenshot, a camera position, and references to the exact elements involved, so whoever receives it can open their own model, jump straight to the problem, and fix it.
BCF is maintained by buildingSMART (like IFC) and is supported by Navisworks, Solibri, Revit add-ins, and most issue-tracking platforms. It is how clash detection results actually travel between teams.
A Revit tool that fills an area with a repeating pattern of parallel beams in one operation. A Beam System fills a sketched boundary with a repeating pattern of parallel structural beams in one operation, instead of placing each beam individually - useful for a regularly-spaced floor framing layout where the spacing and direction can be adjusted as a single parametric rule.
The point at which a client can start using and benefiting from a building, even if minor finishing work is still outstanding. It's an American-contract concept that runs parallel to practical completion in UK contracts - the moment risk and use effectively transfer to the client, snag list or not.
BIM Execution Plan
The project team's plan for delivering BIM. The project team's response to the EIR. The BEP is written by the lead designer or BIM manager and explains how the team will deliver the information the client has asked for.
There are two types:
Every serious BIM project runs on a BEP.
The process of preparing, coordinating, and submitting a competitive tender response for a project. A contractor's tender documents, cost plan, and proposed programme all get pulled together under bid management - a rushed one is a common early source of the risk a later risk register ends up tracking.
Building Information Modeling
The process of creating and managing building data digitally. BIM is not a software - it's a process. It means creating and managing a building's information digitally throughout its entire lifecycle: design, documentation, construction, and operation. At the center of a BIM workflow is a 3D model where every element carries data - not just geometry. A wall isn't just a shape; it has a material, a fire rating, a cost, and a thermal value. That data travels with the model from the architect's desk to the contractor's site to the facility manager's dashboard.
Autodesk Construction Cloud
Autodesk's cloud platform for document management, coordination, and cloud worksharing. Autodesk's cloud construction-management platform - originally launched as BIM 360, now the foundation of Autodesk Construction Cloud (ACC) - covering document management, model coordination, cloud worksharing, field issue tracking, and more, all in one connected environment. For many teams, it is the actual, practical CDE: the place where WIP, Shared, Published, and Archive information genuinely lives, rather than just a theoretical concept from ISO 19650.
Cloud worksharing through this platform has increasingly replaced Revit Server for teams collaborating across multiple offices, since it needs no dedicated server hardware and works from anywhere with an internet connection. ACC was in turn renamed Autodesk Forma in March 2026, so the full lineage runs BIM 360 to ACC to Forma - one product line, three names over time.
An informal role for whoever drives BIM adoption and best practice inside a firm - distinct from BIM Manager or BIM Coordinator, which are formal project or organizational roles. A BIM Champion doesn't necessarily hold a job title with "BIM" in it - often it's simply the most enthusiastic, capable person on a team who ends up training colleagues, pushing for better standards, and advocating for tools and workflows, long before the firm formalizes that role into an actual BIM Manager position.
The role running day-to-day model coordination on a single project. The role that runs the day-to-day, hands-on coordination work on a single project: setting up the federated model, running clash detection, tracking and closing out issues, checking that discipline models are meeting the agreed LOD at each milestone, and keeping the model organized between coordination meetings.
Where the BIM Manager sets the standards and strategy, the BIM Coordinator is the one actually inside the model every day making sure the project follows them - the two roles work closely together, with the coordinator escalating problems the manager needs to solve at a higher level: a contract issue, a persistent process failure, a client pushing back on requirements.
The role owning BIM strategy, standards, and delivery across a firm or project. The role responsible for how BIM actually gets delivered - writing and enforcing the BEP, defining office and project templates and standards, training staff, and making sure the model data a project produces actually satisfies the client's EIR. A BIM Manager operates at a strategic level: firm-wide standards, software rollout, process improvement, sometimes managing a team of BIM coordinators across several projects.
It is a genuinely different job from a BIM Coordinator, who works inside one project's day-to-day model coordination - though on smaller firms and projects, one person often ends up wearing both hats.
BIM Maturity Levels 0-3
The UK framework describing how collaborative a project's BIM process is. A simple 0-to-3 scale (from the UK BIM Task Group) describing how far a project has moved from isolated 2D drawing toward fully collaborative, data-rich BIM:
Most real projects today operate at Level 2 - which is exactly what ISO 19650 was written to standardize.
A vendor-neutral term for a single piece of intelligent, reusable BIM content representing a real product or building component. Whether it's called a Family in Revit, a Component in ArchiCAD, or a Block-with-data in another tool, all of these are BIM objects: geometry plus structured, parametric data (dimensions, material, performance, manufacturer specs) bundled together so it behaves consistently wherever it's placed. Manufacturers increasingly publish their own BIM objects so their real products can be specified directly inside a model.
CIC BIM Protocol
A legal document that inserts BIM obligations into a construction contract. A legal supplement (the best-known version published by the UK's Construction Industry Council) attached to a standard construction contract to make BIM deliverables legally enforceable. On its own, an EIR or BEP is a technical document - it does not carry contractual weight unless something ties it to the actual contract. A BIM Protocol is that tie: it references the EIR/BEP, defines who owns model data, sets out liability if information is wrong or late, and makes model delivery a contractual obligation rather than a best-effort request.
Every serious client who wants BIM deliverables that can actually be enforced needs a protocol like this sitting alongside the technical documents.
An individual or organization offering BIM-related services such as modeling, model auditing, training, or consulting. A catch-all term for outsourced BIM expertise: model managers, BIM trainers, BIM consultants, BIM facilitators, and modeling/auditing bureaus all fall under it. Firms bring in a BIM Service Provider when they need specialist capability or capacity they don't have in-house, rather than hiring a permanent BIM Manager or BIM Coordinator.
The specific purposes a BIM model is put to on a project - such as clash detection, 4D scheduling, cost estimation, or energy analysis - each requiring a different level of model detail and data. Rather than asking "do we need BIM," a project team asks "which BIM uses do we need" - because a model built for design visualization isn't automatically ready for 4D scheduling or quantity takeoff. Planning BIM uses upfront (a concept popularized by Penn State's BIM Planning Guide) is how a BEP decides what level of development each element actually needs.
A free, lightweight IFC model viewer, commonly recommended to students and anyone who needs to open and check an IFC file without a full BIM authoring license. It's a common first stop for checking that an exported IFC file actually opened correctly and looks right, before sending it on to a client or a coordination tool like Solibri or Navisworks.
Graphisoft's server platform for real-time, multi-user collaboration on ArchiCAD models. BIMcloud is Graphisoft's server platform for real-time multi-user collaboration on ArchiCAD models - the ArchiCAD equivalent of Revit's Cloud Worksharing, letting a distributed team work in the same project file simultaneously.
A dedicated BCF-based issue-management platform for BIM coordination. A coordination platform built specifically around BCF issue exchange - rather than a full model-checking tool like Solibri or Navisworks, BIMcollab focuses on making the issue-tracking side of coordination smooth: creating, assigning, discussing, and closing BCF issues in a shared, structured workspace that plugs into Revit, Navisworks, Solibri, and most other major BIM tools.
It is a good example of how openBIM actually plays out day to day: a team can use completely different modeling software from each other and still coordinate cleanly, because the issue itself travels as a standard BCF file rather than being locked to one vendor's platform.
A critical term (modeled on "greenwashing") for a firm or product that claims BIM capability or maturity without the underlying processes to back it up. The label usually gets applied to marketing that claims "BIM Level 2" or "full BIM" compliance while the actual delivery is still 2D drawings with a token 3D model, or a firm that owns Revit licenses but never adopted the collaborative CDE, standards, and information-management processes that make BIM actually work.
Biodiversity Net Gain (BNG)
A planning requirement that a development leaves biodiversity measurably better off than before it started, not merely no worse. It's now mandatory for most new developments in England, using a standardized metric to score habitat value before and after - a young standard, but already as unavoidable in a planning application as an energy assessment.
A free, open-source 3D creation tool - modeling, animation, and rendering - increasingly used in AEC visualization pipelines and, via add-ons, openBIM workflows. On its own it knows nothing about walls or fire ratings - it's a general 3D tool, not a BIM authoring platform - which is exactly why an add-on like BonsaiBIM exists to bridge that gap.
Bluebeam Revu
PDF markup and collaboration software widely used across the construction industry for drawing review, redlining, and digital quantity takeoffs. Long before a design ever reaches the model in detail, plan reviewers, contractors, and clients mark up exported PDF sheets in Bluebeam with comments, clouds, and measurements - it's become the industry-standard review layer that sits on top of, not inside, the BIM authoring tools themselves.
Building Management System
The control system that actually runs a building's HVAC, lighting, and other systems. The computer control system that actually operates a building's mechanical and electrical equipment day to day - HVAC, lighting, access control, sometimes fire and security systems - monitoring sensors and adjusting equipment automatically to keep the building running efficiently. Also called a BAS (Building Automation System) in some regions.
The BMS is where a building's 7D and AIM data becomes genuinely operational: equipment tags and system data captured in the model during design and handed over through COBie are exactly what a BMS needs configured correctly to actually control the right piece of equipment - a poorly handed-over model means a facilities team reprogramming and relabeling everything manually after move-in.
BonsaiBIM (formerly BlenderBIM)
A free, open-source add-on turning Blender into a full IFC-native BIM authoring tool - built and maintained by the openBIM community. Unlike Revit or ArchiCAD, which export to IFC as an afterthought, BonsaiBIM stores its data as IFC natively from the start - a genuinely different approach to what "open BIM" can mean in practice.
Bill of Quantities
A detailed, priced document listing all the materials, parts, and labor required for a project, used for tendering and payment valuation. Where QTO is the process of measuring quantities from a model, the Bill of Quantities is the resulting priced document contractors use to submit tenders and clients use to value work completed - BIM-derived BOQs update automatically as the design changes, instead of requiring a full manual re-measure.
Building Research Establishment Environmental Assessment Method
The UK's leading green-building certification system, LEED's main international counterpart. The UK-originated equivalent to LEED - a green-building assessment method (from BRE) covering energy, health and wellbeing, materials, waste, and land use, with ratings from Pass up to Outstanding. BREEAM dominates UK and many international projects the way LEED dominates North American ones, and the two are frequently mentioned together as the two most recognized systems worldwide.
Like LEED, BREEAM does not mandate BIM, but a well-modeled, data-rich project makes assembling the evidence a BREEAM assessment requires far faster than compiling it from scattered spreadsheets and drawings after the fact.
Revit's setting for grouping and sorting the Project Browser's view list by custom rules - by discipline, phase, or sheet number - instead of the flat default order. On a large project with hundreds of views, a well-set-up browser organization (grouped by discipline then phase, for example) is often the difference between finding the right view in seconds or scrolling through an unsorted list for a minute.
BS 1192:2007
The earlier British standard for collaborative production of architectural information. The British Standard that predates even PAS 1192 - BS 1192:2007 introduced the collaborative, disciplined file-naming and layering conventions that later BIM standards inherited: a consistent naming code (project-originator-volume-level-type-role-number), and the idea of a shared, structured folder environment for a project team.
Most of what BS 1192 pioneered is now folded into ISO 19650's naming and CDE requirements, but the standard is still occasionally referenced directly, especially for its file-naming convention, which many UK and international offices still use as a base template.
Code of practice for noise and vibration control on construction and open sites
The UK code of practice for predicting and controlling noise and vibration from construction site activities. BS 5228 is the UK code of practice for predicting, measuring, and controlling noise and vibration generated by construction and demolition activities - piling, breaking, plant movement - used to set permissible working hours and site-boundary noise limits, and often referenced directly in a planning condition or Section 106 agreement.
BS 7671: Requirements for Electrical Installations (IET Wiring Regulations)
The British standard governing the design, installation, and inspection of electrical wiring - the reference every electrical modeling decision in a Revit MEP project ultimately has to satisfy. Cable sizing, circuit protection, and containment routing in an electrical Revit model all trace back to BS 7671 requirements - a model can look complete and still fail inspection if the underlying electrical design doesn't actually comply.
BS 8536: Design and Construction of Buildings and Infrastructure - Code of Practice for Facilities Management
A British code of practice for briefing and designing with the building's whole operational life in mind, closely linked to Soft Landings and facilities-management handover. BS 8536 pushes the facilities-management team's needs into the brief from day one - room adjacencies, maintenance access, and expected equipment lifespans are captured before design starts, rather than discovered as problems after the building is handed over.
Library objects for architecture, engineering and construction - Part 1: Identification and classification
The British Standard defining how BIM library objects (families) should be named, classified, and identified consistently across a project or an object library. It's the standard behind the idea of a permanent, structured object code - exactly the kind of naming discipline a well-run family library, including this site's own Revit family library, is built on.
Library objects for architecture, engineering and construction — Recommended 2D symbols of building elements
The UK standard specifying how 2D symbols for building elements should look and behave in a BIM object library. BS 8541-2 sits alongside BS 8541-1 in the same object-library series, but covers 2D representation - how a door, window, or fitting should symbolize itself in plan and section - rather than 3D geometry and data. Object library authors use it to keep symbols consistent regardless of which manufacturer built the family.
Fire safety in the design, management and use of buildings — Code of practice
A UK fire-safety code of practice offering a more flexible, engineered alternative to Approved Document B. BS 9999 is a UK fire-safety code of practice used as a more flexible, engineered alternative to the prescriptive guidance in Approved Document B - allowing a fire engineer to justify a different approach (longer travel distances, alternative escape strategies) than the standard guidance permits, provided the reasoning is documented, often in the project's Fire Strategy Report.
buildingSMART Data Dictionary
buildingSMART International's free, online, multilingual dictionary of standardized construction concepts and properties, mapping classification systems like Uniclass and OmniClass to a single shared reference. It's the practical answer to the data dictionary problem at industry scale - rather than every country or software vendor defining "fire rating" its own way, bSDD gives IFC-based workflows a shared, queryable source for what a property actually means.
The approval and inspection process confirming a building complies with Building Regulations. Building Control is the approval and inspection process - carried out by a local authority or an approved private inspector - that confirms a building complies with Building Regulations, running in parallel with and separately from planning permission. Site inspections happen at defined stages, ending with a completion certificate once the finished building passes.
The full span of a building's existence, from brief to demolition. The full span a building exists across: brief and feasibility, design, construction, handover, operation - typically the longest phase by far - and eventually renovation, retrofit, or demolition. BIM's whole value proposition rests on this timeline: information created cheaply during design (changing a wall is trivial on screen) becomes exponentially more expensive to create or correct the later in the lifecycle you leave it, which is exactly why front-loading data quality is worth the extra effort.
The dimension stack (3D through 10D) essentially maps onto this lifecycle in order - geometry, time, and cost during delivery, then energy, facility management, and safety data carrying the project through decades of operation afterward.
A living operational record of a building - how its systems are meant to be run, key contacts, and performance targets - kept updated throughout its life, not just handed over once. Unlike a static O&M Manual delivered once at handover, a log book is meant to be a living document that gets updated as equipment is replaced or operating strategies change - a Soft Landings requirement that treats the building's documentation as something that ages with the building itself, not a one-time deliverable.
A Revit site element that carves a flat, level area into a toposurface for a building's foundation to sit on. A Building Pad carves a flat, level excavation into a Toposurface at a defined elevation, giving a building's foundation a proper level base to sit on instead of the surrounding terrain's natural slope - the site-modeling counterpart to a structural foundation, needed before the toposurface can be trusted for accurate cut/fill quantities.
Building Performance Simulation (BPS)
Computer modeling of a building's energy use, daylighting, thermal comfort, or airflow, run against the BIM model to inform design decisions before construction. Dedicated simulation tools pull geometry, materials, and location data out of Revit to test "what if" scenarios - window-to-wall ratio, shading depth, HVAC sizing - long before a single wall is built, and increasingly tie directly into embodied and operational carbon reporting.
The UK statutory minimum standards a building must meet, published as the numbered Approved Documents. Building Regulations are the statutory minimum a building in the UK must meet - structural safety, fire, access, energy performance, and more - enforced separately from planning permission. Each topic is published as its own Approved Document (Part B for fire, Part M for access, Part L for energy), and BIM models are increasingly checked against them through automated code-compliance tools.
Building Safety Act 2022
Major UK legislation, passed after the Grenfell Tower fire, introducing a new regulatory regime and legal duties for the safety of higher-risk buildings. It's the legal source behind the golden thread and the building safety case requirements - not just recommended good practice, but a statutory duty with real legal consequences for getting it wrong.
A UK regulatory requirement (post-Grenfell) for higher-risk buildings, presenting the evidence that fire and structural safety risks have been properly managed across the building's whole lifecycle. A safety case has to be actively maintained and updated throughout occupation, not filed away once at completion - it relies directly on the Golden Thread of accurate, up-to-date building information staying connected to the physical asset for as long as the building exists.
The UK body that approves and inspects higher-risk buildings under the post-Grenfell Building Safety Act regime. The Building Safety Regulator (BSR) is the UK body responsible for approving and inspecting higher-risk buildings (broadly, residential buildings above 18m) at three statutory gateways - planning, pre-construction, and completion - under the regime the Building Safety Act established. A project can't proceed past a gateway without BSR sign-off, and the Golden Thread of information is what the BSR expects to be able to review at each one.
A plain-language guide explaining how to use and understand a building, aimed at its occupants - distinct from the technical O&M manual written for maintenance staff. It's a core soft landings deliverable - a building can be technically perfect and still perform badly if nobody who actually works in it understands how the heating controls or blinds are meant to be used.
The physical, completed building or piece of infrastructure that a project delivers - the real-world counterpart to its Asset Information Model. "Built asset" is the vocabulary ISO 19650 uses for the actual structure once it exists, as distinct from the information models describing it. The term shows up throughout asset-management and handover discussions specifically to keep "the building" and "the model of the building" from being confused with each other.
A Revit electrical system family that routes and supports bundled cabling, modeled and sized separately from conduit. Cable tray is used where large quantities of cable run together openly rather than through individual conduit runs - typically risers, ceiling voids, and plant rooms - and like duct and pipe, Revit auto-generates fittings as runs bend or branch. It's a distinct family category from Conduit, which routes individual or small bundled circuits through an enclosed tube.
A Revit view type showing an enlarged, cropped portion of another view - used for detail drawings that zoom into a small area without duplicating the whole plan or section. A callout stays linked to its parent view - move a wall in the plan, and the callout's cropped detail view updates with it - which is what makes it the right tool for a wall-section detail or a stair detail, instead of drafting a disconnected duplicate view that would silently go out of sync.
A perspective 3D view in Revit created by placing a camera at a specific point and direction, framing the model the way a photograph would. It's the starting point for a walkthrough - a single static camera view is one frame; a walkthrough is a whole path of them animated together.
Measuring and tracking a project's actual carbon emissions - embodied and operational - against its targets, throughout design and construction. It's the practice of measurement that embodied carbon and whole-life carbon are the subjects of - without carbon accounting built into the model and the procurement process, a net-zero target stays a stated ambition rather than a tracked, verifiable number.
Compensating for a project's carbon emissions by funding an equivalent carbon reduction elsewhere, rather than reducing the emissions themselves. It's deliberately the last resort in most net-zero strategies - carbon accounting exists precisely to prove how much genuine reduction happened first, before offsetting is used to cover whatever's left.
A Revit family category for built-in cabinetry and millwork - kitchen counters, storage units - usually wall- or floor-hosted. Unlike freestanding furniture, casework is typically hosted to a wall or floor and modeled as fixed built-in work, common in kitchens, bathrooms, and joinery-heavy interior fit-outs. It's tracked separately from Furniture in schedules since it's usually procured and installed by a different trade.
Projecting when money will actually be received and paid out over the course of a project, not just how much the total will eventually cost. A project can be profitable overall and still run out of cash mid-way through if payments and costs aren't timed properly - which is exactly the gap cash flow forecasting exists to catch before it becomes a crisis.
Category A and Category B Fit-Out
A commercial fit-out scope split - Cat A delivers a basic finished shell (raised floors, ceilings, basic MEP) ready for occupation, and Cat B is the tenant-specific layer (partitions, furniture, branding) built on top of it. A landlord's model typically stops at Cat A, and the tenant's fit-out contractor picks up from there in their own Cat B model - meaning the two models need clean, well-defined interfaces (a shared coordinate system and a clear scope boundary) even though they're built at completely different times by completely different teams.
Revit Category
The top-level grouping every Revit element belongs to, like Walls or Doors. The highest level of Revit's element hierarchy: Category to Family to Type to Instance. Every element in a project belongs to exactly one category - Walls, Doors, Windows, Structural Columns, Mechanical Equipment - and the category controls fundamental behavior: which parameters are available, how the element schedules, what line weights and graphics it gets by default, and which views it shows up in.
Categories are fixed by Revit itself (you cannot invent a new one), which is exactly why they map so cleanly onto external classification systems like Uniclass or MasterFormat - they are the stable anchor point that makes automated classification and scheduling possible.
Common Data Environment
The shared platform for all project information. The single shared platform where all project information is stored, managed, and distributed. Instead of files flying around by email, everything lives in the CDE - models, drawings, documents, correspondence.
A CDE divides project information into four key zones:
| Zone | Who has access | What it contains |
|---|---|---|
| WIP (Work in Progress) | Creator only | Unfinished work not yet ready to share |
| Shared | Project team | Information approved for coordination |
| Published | Client & stakeholders | Formally issued deliverables |
| Archive | All | Superseded versions, kept for record |
The CDE is the backbone of ISO 19650-compliant BIM workflows.
Construction (Design and Management) Regulations
UK health-and-safety regulations that require design and construction risk to be identified and managed from the earliest design stage, with the model itself often used to flag hazards. CDM shifts safety responsibility upstream - designers must actively design out foreseeable hazards (a difficult access route, a maintenance task requiring work at height) rather than leaving all risk mitigation to the contractor on site, and the Health and Safety File is the document that carries this information into operation.
A horizontal Revit system family, usually placed automatically within a room's walls, that forms the finished underside of a floor or roof above. Ceilings are typically placed by picking a room boundary rather than sketched by hand, and their type carries either a compound layer structure (plaster/drywall) or a modular grid pattern for suspended ceiling tiles. Light fixtures, sprinklers, and diffusers commonly host to a ceiling's face or grid.
The single master copy of a workshared Revit project, stored on a shared location, that every team member's local file synchronizes with. When a Revit project uses worksets, one file is designated the central model - the authoritative version everyone's changes eventually flow into via Synchronize with Central. It should never be opened and edited directly; everyone works from their own local file instead.
The certificate confirming that defects identified during the defects liability period have been properly fixed, issued once that period ends. It's the formal close-out of the defects liability period - the contractor's last remaining obligation before retention money is released in full. Without it, a client has no documented confirmation that the snagging list was actually cleared rather than just quietly ignored.
Civil Engineering Standard Method of Measurement, 4th edition
The UK standard method for measuring and describing civil engineering work in a bill of quantities - the civil-engineering counterpart to NRM for buildings. A quantity surveyor pricing a road or a bridge measures it against CESMM4; the same surveyor pricing a building measures it against NRM instead.
The formal process for proposing, approving, and tracking design changes. The formal process for handling a design change once a project is underway: proposing it, assessing its impact on cost, schedule, and other disciplines, getting it formally approved, and making sure everyone working from the model actually knows it happened. Without disciplined Change Management, a "small" change made by one team can silently break another team's coordinated work, since nothing forced the change to be reviewed or communicated before it landed in the shared model.
A well-run CDE supports change management directly: moving a changed element through WIP to Shared is itself a form of controlled, visible change, rather than an edit that just quietly appears in someone else's next model sync.
A formal contractual document authorizing a specific change to scope, cost, or schedule after a contract has already been signed. Where Change Management is the ongoing process of controlling and evaluating proposed changes, a Change Order is the specific, signed document that actually authorizes one - often triggered by a coordination clash or an RFI response that reveals the original design can't be built as documented.
A GPU-accelerated real-time ray-tracing renderer from the makers of V-Ray, used for instant, photorealistic walkthroughs of a scene. Where V-Ray is built for high-quality offline stills, Vantage trades some of that fidelity for instant interactivity - closer in spirit to Enscape or Twinmotion than to its own sibling product.
Chartered Institution of Building Services Engineers
The UK's chartered professional body for building services (MEP) engineers, publishing widely-used technical guidance for HVAC, electrical, and public health design. Its guides are to MEP engineers roughly what NRM is to quantity surveyors - a reference so widely adopted that a design brief referencing "CIBSE guidance" is usually understood without further explanation.
Design methodology for the assessment of overheating risk in homes
The CIBSE technical methodology used to assess a home's risk of overheating. CIBSE TM59 sets out the specific methodology - which rooms to model, which weather file to use, what counts as a pass or fail - behind a project's Overheating Assessment for residential buildings, giving assessors a consistent standard to test against rather than each firm inventing its own criteria.
Designing buildings so materials can be reused or recycled instead of demolished to waste. A design and construction philosophy focused on keeping materials in use for as long as possible - designing for disassembly rather than demolition, specifying reclaimed or recyclable materials, and treating a building's components as a future resource rather than eventual waste. It sits alongside embodied carbon reduction as one of the main levers for cutting a building's environmental footprint.
BIM supports circular-economy thinking in a very concrete way: a model with accurate material data becomes a material passport for the building - a record of exactly what is in the structure and where, making future disassembly, reuse, or recycling actually feasible instead of guesswork decades later.
An open data standard for representing and exchanging 3D city and landscape models, at a coarser level of detail than a building-scale IFC model. Where IFC models a single building in rich detail, CityGML models an entire city more shallowly - the two meet in GIS-BIM integration work, each covering the scale the other doesn't.
Autodesk Civil 3D
Autodesk's civil engineering and infrastructure design software - handles roads, grading, and site utilities, and links to Revit for combined building-plus-site coordination. Where Revit models the building, Civil 3D models everything around it - roads, drainage, earthworks, and utility networks - and the two share data (often via a shared coordinate system) so a building's foundation and grading design stay coordinated with the surrounding site plan.
Automatically finding conflicts between discipline models. The process of automatically identifying conflicts between elements in different discipline models. When the MEP engineer's duct runs through the structural engineer's beam, clash detection flags it - digitally, in the model - before it becomes a costly problem on site.
Clash detection is run in tools like Autodesk Navisworks or Solibri. There are three types:
Uniclass / OmniClass
A standard code for every component and system. For information to be usable across organizations, elements need a shared cataloguing language. Uniclass (UK) and OmniClass (North America) are hierarchical classification systems that give every component, system and activity a standard code - from a single door to an entire project stage.
The codes live as parameters on elements and enable consistent quantities, specifications and information requirements across all parties. You will meet them mostly on international projects and in the EIRs of large clients.
An independent inspector who checks construction work on site matches the specification and drawings. A Clerk of Works is an independent inspector, appointed by the client, who checks day to day that work on site actually matches the specification and drawings - a quality-assurance role that predates BIM by well over a century but still operates the same way, walking the site rather than reviewing a model.
Running a Revit worksharing project through Autodesk's cloud services instead of a local network file server, so distributed teams can collaborate on the same central model from anywhere. It replaces the old requirement of a Revit Server or shared office network with the same synchronize-with-central workflow teams already know - the meaningful difference is where the central model physically lives, not how users actually work with it day to day.
Physically placing project team members from different organizations - designer, contractor, key subcontractors - in the same workspace to improve collaboration and speed up decisions. It's a common feature of integrated project delivery and other collaborative delivery models - a clash resolved in a five-minute conversation across a shared desk instead of a week of emails between separate offices is exactly the benefit co-location is meant to capture.
Construction Operations Building Information Exchange
Structured data handover for facility managers. A structured data format for handing over asset information from the construction team to the facility management team at project completion. COBie is typically delivered as a spreadsheet and contains every piece of information a building operator needs: spaces, systems, equipment, maintenance schedules, warranties, and spare parts.
COBie is how the 7D dimension actually gets delivered in practice.
Verifying that a design meets applicable building codes and regulations, increasingly done by running automated rule checks directly against the model's own data. Digital permitting is this idea taken all the way to the regulator's own desk; most projects still run a version of it privately first, using IDS-style rules to catch violations before submission.
A multi-party agreement, often built on a template like the CIC BIM Protocol, defining how project participants will actually work together and share information. Where a BIM protocol is a standard template of clauses, a collaboration agreement is the actual signed document for a specific project, naming the real parties and their real obligations.
A legal agreement extending a duty of care from a designer or contractor to a third party (like a funder, tenant, or future purchaser) who wasn't part of the original contract. Without a collateral warranty, a building's future owner or lender would have no direct contractual right to sue the original architect or contractor if a defect appears - this is the legal document that gives them standing, separate from the main construction contract and separate from a product Warranty covering physical materials.
A Revit plan view showing rooms or areas color-coded by a chosen parameter - department, occupancy, fire rating - with a matching legend, instead of plain black-and-white linework. It's a distinct feature from a general legend view - the color scheme is defined once against a parameter (like department name) and every room tagged with that value picks up its color and its entry in the legend automatically.
The formal process of testing and verifying that building systems actually work as designed before a project is handed over to the client. A commissioning agent runs HVAC, electrical, and life-safety systems through their real operating conditions - not just checking they're installed, but that they perform to spec - and the results feed directly into the O&M Manual and the facilities-management team's baseline for what "working correctly" looks like.
The certificate confirming a building's systems have been tested against the commissioning plan and are verified to work as designed. It's what a client should actually expect to see before switching on a building's systems for real occupants - not just a contractor's word that testing happened.
The document setting out how a building's systems will be tested and verified to work as designed before handover. It schedules which system gets tested when and by whom, feeding directly into the commissioning certificate issued once every test has actually passed.
A standardized UK charge on new development used to fund local infrastructure like schools and roads. The Community Infrastructure Levy (CIL) is a standardized, per-square-metre charge some UK local authorities impose on new development to fund local infrastructure - schools, roads, parks - calculated by a fixed rate rather than negotiated case by case, unlike a Section 106 Agreement.
A defined event under NEC-family contracts that entitles the contractor to an adjustment to the price and/or completion date - the NEC's structured equivalent of a variation or claim. NEC contracts list exactly which events qualify (a change instructed by the client, an unforeseen physical condition, and others), and require them to be assessed and priced quickly - a structured alternative to the more open-ended change order and claim processes used elsewhere.
The layered assembly definition (structure, insulation, finish, etc.) behind a system family like a wall, floor, or roof - each layer carrying its own material, thickness, and function. Editing a wall type's compound structure is how a modeler defines what it's actually made of layer by layer - which is what drives its fire rating, thermal performance, and the material quantities that flow into schedules, rather than the wall just being a single generic slab with no real construction logic behind it.
Massing
A simplified 3D volume used to explore building form before real elements are modeled. A simplified, freeform 3D shape used in Revit's conceptual design environment to explore a building's overall form and massing - footprint, height, setbacks - before committing to real walls, floors, or roofs. Faces of a mass can be converted directly into actual building elements once the form is settled, so early massing work is not thrown away, it becomes the starting geometry for the real model.
Massing is also where a lot of early 6D analysis happens - solar studies, floor-area calculations, shadow studies - because it lets a design team test many volumetric options quickly, before the cost of full detailed modeling makes changes expensive.
A situation where a client-caused delay and a contractor-caused delay happen to overlap in time, making it genuinely hard to say who's responsible for the resulting overrun. It's one of the most litigated topics in construction contract disputes - an extension of time claim gets genuinely complicated when both sides can point to a real delay happening on the exact same days.
Running design, engineering, and analysis tasks in parallel across disciplines on a shared model, instead of waiting for each discipline to finish before the next one starts. BIM's shared model and worksharing make concurrent engineering practical: architects, structural engineers, and MEP teams can develop their own disciplines simultaneously on linked or worksets-based models, catching conflicts early through regular clash detection instead of discovering them at the end of a traditional, sequential handoff chain.
An assessment recording the current physical state of an existing building, before deciding what work it actually needs. It's often the first real step on a retrofit or refurbishment project - and increasingly done via a laser scan feeding straight into a scan-to-BIM model rather than a hand-drawn sketch.
A Revit electrical system family - an enclosed tube that routes individual or small bundled circuits, sized and fitted separately from cable tray. Conduit connects through connectors on electrical equipment and devices, auto-generating fittings as runs are drawn, and its diameter is typically sized to the number and gauge of conductors it needs to carry. It's the go-to system for individually protected circuits, where Cable Tray is used instead for open bulk cable runs.
A defined point on an MEP family where it can link to another element - a pipe's connector meeting a fitting's connector, carrying flow and system data across the joint. It's what lets Revit auto-route a duct or pipe run and validate that a system is actually continuous - two elements that look connected in a view but don't share an actual connector aren't really joined at all.
A UK scheme that registers and scores construction sites on how considerately they behave toward their neighbors, the public, and the environment. It scores things a building's own quality plan doesn't cover at all - noise, site tidiness, how workers are treated - a reputational layer sitting alongside the purely technical compliance checks.
How practically buildable a design actually is, reviewed before construction starts. How practical and buildable a design actually is in the real world - whether a detail can physically be assembled in the sequence intended, whether a component can fit through the access route it needs to reach its final position, whether the design assumes tolerances the trades on site can actually achieve. A formal Constructability Review brings contractor and trade expertise into the design process early, specifically to catch these problems on screen instead of on site.
Clash detection catches whether two elements physically overlap; constructability review catches the broader, harder question of whether a design that has zero geometric clashes can still actually, practically be built the way it was drawn.
A formal review session where contractors and specialists check a design specifically for how practical and safe it will actually be to build. Constructability itself is the general quality a design either has or lacks; a constructability review is the specific, scheduled meeting where someone actually checks for it before it's too late to change.
Housing Grants, Construction and Regeneration Act 1996
UK legislation giving parties a statutory right to adjudication and setting minimum payment terms for construction contracts. It's the legal foundation adjudication actually rests on - without it, the fast, statutory dispute route construction relies on so heavily wouldn't exist as a legal right at all.
The health-and-safety document, required under the CDM Regulations, setting out how a specific construction project will be managed safely on site. Written by the principal contractor before work starts and kept live throughout the build, it covers site rules, welfare arrangements, and how specific risks identified in the design will actually be controlled in practice. It's a legal requirement on UK projects of any real size, not an optional add-on.
The person who administers a traditional (non-Design and Build) construction contract on the client's behalf. A Contract Administrator (CA) administers a traditional construction contract - typically JCT - on the client's behalf: issuing instructions, certifying payment, and confirming Practical Completion. It's usually the architect or a project manager wearing this specific contractual hat, and it's the traditional-procurement counterpart to the Employer's Agent role used on Design and Build.
A breakdown of a lump-sum contract price into its component parts - by element or trade - used to value work done and assess variations. Without it, a lump-sum contract is a single number with no way to check progress payments against actual work completed - the contract sum analysis is what a quantity surveyor values interim certificates against.
Contractor's Design Portion (CDP)
A defined part of the design - often specialist elements like curtain walling or MEP - that the contractor takes responsibility for designing, even under an otherwise design-bid-build contract. It's a common middle ground between the two extremes - the client's team retains design control over most of the building, while handing the specialist parts to whoever is actually best placed to design them.
The contractor's response to the Employer's Requirements in a Design and Build contract, showing how they'll deliver it. Contractor's Proposals is the contractor's response to the Employer's Requirements in a Design and Build contract - showing how they intend to meet each requirement, at what price, and where their design differs from what was asked for. Together the two documents form the technical and contractual basis of the agreement.
A Revit coordination tool that copies elements (like grids and levels) from a linked model into the current one, then flags an alert if the original later moves out of sync. A structural engineer commonly uses Copy/Monitor to bring the architect's grids and levels into their own model rather than redrawing them by hand - and if the architect later shifts a level's elevation, Revit flags the discrepancy automatically instead of the two models silently drifting apart.
A photorealistic rendering engine from Chaos - the same company behind V-Ray - popular for its simpler, more streamlined interior visualization workflow. It's Chaos's more approachable sibling to V-Ray - fewer settings to tune, at some cost to the fine-grained control V-Ray offers to experienced visualization artists.
An evolving budget estimate for a project, refined in detail as design progresses from an early feasibility figure to a full elemental breakdown. An early-stage cost plan might be a single per-square-meter figure; by the time it reaches a contract sum analysis it's broken down element by element - the same document maturing alongside the design.
Quantity takeoff and cost estimating software that measures directly off a BIM model or 2D drawings to produce a priced Bill of Quantities. A quantity surveyor links CostX directly to the Revit model (or an exported IFC file) so measured quantities update automatically as the design changes, instead of manually re-measuring drawings every time a revision comes through - the same underlying goal as Assemble Systems, from a cost-estimating-first rather than model-coordination-first tool.
Critical Path Method (CPM)
A scheduling technique that identifies the longest sequence of dependent tasks in a project - the tasks that, if delayed, delay the entire project's finish date. Everything on the critical path matters for the finish date; everything off it has some slack - which is exactly why a good project manager watches the critical path far more closely than the rest of the schedule.
The rectangular (or shaped) boundary limiting how much of the model a Revit view actually displays, independent of the view's scale or the model's true extents. Shrinking a floor plan's crop region to just the area a sheet needs, rather than showing the entire model at that scale, is one of the most basic ways a Revit user controls what actually prints on a drawing sheet.
Construction Skills Certification Scheme
A UK card scheme proving that a construction worker has the training and qualifications for their specific role, required to access most UK construction sites. It's a practical, everyday gatekeeper - a site's security gate checks it before anyone gets in, regardless of how good their actual work is.
The Revit grid lines dividing a Curtain Wall into panels, controlling where mullions and panels are placed. A Curtain Grid divides a Curtain Wall or Curtain System into individual panels by placing horizontal and vertical grid lines - evenly spaced, fixed distance, or a fixed number - and it's this grid, not the wall itself, that controls exactly where each Mullion and Curtain Panel gets placed.
The individual infill element - glazed, solid, or an embedded door - filling one cell of a Curtain Grid. A Curtain Panel is the individual infill filling one cell of a Curtain Grid - typically glazing, but it can just as easily be a solid spandrel panel or an embedded door family - and because each panel can be swapped independently, a single curtain wall can mix glazed and opaque sections without modeling separate wall types.
A curtain grid applied directly to a mass or roof face, rather than following a wall's linear path the way a Curtain Wall does. Where a Curtain Wall is fundamentally a wall type that happens to be paneled, a Curtain System is applied face-by-face to conceptual massing or a complex roof shape - useful for a sloped glazed atrium roof or a faceted facade that doesn't sit on a single straight or curved wall path. Both share the same underlying panel/mullion mechanics.
A Revit wall type built from a grid of panels and mullions rather than solid layers - the standard system for modeling glazed facades. Instead of a uniform wall assembly, a Curtain Wall is defined by a grid pattern that divides it into panels (usually glass, but swappable to solid or louvered), with mullions running along the grid lines - making it the go-to system for anything from a single shopfront to a full glazed office tower facade.
A Revit tool that lets one element cut a void through another - a duct passing through a wall - so they display correctly instead of solidly overlapping. It's the counterpart to Join Geometry for elements that need to pass through each other rather than merge - without it, a duct routed through a wall would just show as a solid block colliding with it.
The horizontal height within a Revit view's range at which the model is "sliced" to generate a plan view - the setting inside View Range that decides what shows as a solid cut line. Set it too low on a floor plan and a low window sill won't show as cut; set it too high and it might cut through a door head instead of the wall below it - it's the specific value inside view range most plan-reading confusion actually traces back to.
A real-time, GPU-based rendering engine popular for fast, high-quality architectural visualization directly from a live 3D scene. It competes directly in the same space as Enscape, Lumion, and Twinmotion - real-time visualization tools built to sit alongside an authoring model rather than replace it.
The role responsible for the day-to-day storage, security, and technical upkeep of a dataset, as distinct from its Data Owner. A Data Custodian handles the day-to-day storage, access control, and technical upkeep of a dataset - as distinct from the Data Owner, who decides what the data should be and who's allowed to use it. On a BIM project the Data Custodian is often whoever administers the CDE itself, executing the rules a Data Governance framework sets rather than setting them.
A structured, shared reference of standardized property names and definitions - so that "fire rating" means exactly the same thing to every software and every party using the model. Without a shared data dictionary, one tool's "FireRating" and another's "Fire_Rating_Class" describe the same property under two different names, breaking any automated check or handover. buildingSMART's own bSDD is the best-known public example, mapping classification systems like Uniclass and OmniClass to a single online reference.
A scheduled milestone at which agreed information must be delivered. A term from the PAS 1192 / ISO 19650 world for a scheduled point in a project where a specific, pre-agreed set of information must be delivered into the CDE - not a vague "send it when it's ready," but a fixed milestone tied to the project's MIDP. Missing a data drop is treated the same as missing any other contractual deadline.
Data drops are what make the MIDP and TIDP more than a theoretical schedule - they are the concrete checkpoints a project team is actually held to, usually aligned with major project stages like the end of a design phase or a construction milestone.
The policies and assigned ownership that decide who can create, edit, and approve project data throughout its lifecycle. Data Governance defines who owns each piece of project information, who is authorized to change it, and what approval a change needs before it's trusted downstream. On a BIM project this typically means assigning a data owner to each information container, agreeing validation rules before data enters the CDE, and keeping an audit trail of who changed what. Without it, concepts like Data Quality and Data Ownership stay aspirational instead of enforced.
How finely broken down a piece of information is - a single "HVAC system" entry versus every individual duct, damper, and diffuser recorded separately. The right granularity depends on who's asking - an FM team tracking filter changes needs duct-level detail, while a portfolio cost report is better served by a system-level rollup. LOD is granularity applied to geometry; this is the same idea applied to data.
The traceable history of where a piece of information originally came from and how it changed as it passed between people, tools, and project stages. If a room's fire rating changes three times across design, construction, and handover, data lineage is what lets someone trace it back to figure out which change was correct and who made it.
Moving data from one system, software, or format to another without losing or corrupting it along the way. Switching FM software, or moving a legacy asset register into a new AIM, is a data migration project in its own right - and exactly where poor data quality upstream turns into a very expensive cleanup job.
The contractual question of who legally owns and controls the BIM model and its data after a project ends - the architect, the client, or a shared arrangement. Without clear contract language, a client can be left legally unable to update or even fully access the model they paid for, which is exactly why modern appointment documents (like a BEP) spell out data ownership and licensing terms as explicitly as they spell out fees and deliverables.
How accurate, complete, and consistent a model's underlying data actually is - independent of how good the geometry looks. A perfectly modeled door with a blank fire-rating field has excellent geometry and poor data quality - exactly the kind of gap model quality review and data validation checks exist to catch.
The practice of getting every party on a project to structure and name their data the same way, so it can be combined and compared without manual cleanup. A data dictionary or a shared classification system like Uniclass are the tools; data standardization is the ongoing discipline of actually enforcing them project after project, not just publishing them once.
A standardized, reusable set of parameters and properties defined for a category of BIM object, so every instance of that object type carries consistent, structured data. Instead of every manufacturer or modeler inventing their own property names for, say, a fire door, a data template (like the UK's NBS BIM object standard) fixes the exact parameters, units, and value types expected - which is what makes data genuinely interoperable and searchable across projects and software, not just geometrically compatible.
Automatically checking a model or a specific data drop against a defined set of rules before it's accepted into the project's information. Instead of a human manually checking that every door in a submission has a fire-rating parameter filled in, a validation tool applies an IDS ruleset (or a similar checker) automatically, rejecting or flagging any element that doesn't meet the agreed information requirements before it ever reaches the shared model.
Simulating how much natural light reaches inside a building's spaces, used to check comfort, energy performance, and planning-approval daylight requirements. It runs on the same model geometry sun-path studies use, but focuses on interior comfort metrics rather than just tracking where shadows fall outside.
A planning-stage report assessing how a proposed building affects daylight and sunlight to neighboring properties. A Daylight and Sunlight Assessment evaluates how a proposed development affects the daylight and sunlight reaching neighboring buildings and the amenity spaces around the new one itself, following BRE guidelines. It's a frequent planning objection trigger in dense urban schemes, and its findings can force a massing change well before Daylight Analysis is run on the detailed model.
Taking a building apart carefully to recover and reuse its materials and components, rather than demolishing it into waste. It's demolition planning's circular-economy-minded sibling - slower and more expensive up front, but exactly what makes material passporting and reverse logistics worthwhile downstream.
A fixed period after handover during which the contractor remains contractually obligated to fix any defects that surface, usually before final payment is released. Snags logged during this period get tracked the same way as pre-handover issues - often against the same model elements - and clearing them all is usually the condition for releasing retention money withheld from the contractor's final payment.
Planning how an existing structure will be safely taken down, including sequencing, structural stability during the process, and waste handling. An asbestos register and a condition survey both usually come before demolition planning starts, since what's actually in a building changes how it can safely be taken apart.
Copies of a Revit view (usually a large plan split across several sheets) that stay linked to the original - editing shared elements in one updates all the others automatically. A plain "Duplicate" copy is a completely independent view; a dependent view stays tied to its parent, which is exactly what's needed when the same large floor plan has to appear split across matchlines on multiple sheets.
A document submitted with a planning application explaining the design thinking behind a proposal and how the scheme will be accessible to everyone who uses it. It's the narrative that justifies the drawings - explaining why a building looks and sits the way it does, not just showing that it does.
A procurement route where a single contractor is responsible for both design and construction, typically taking over the design team (often via novation) once a contract is signed. Because one party controls both design and construction, Design and Build tends to concentrate BIM decision-making and risk with the contractor - a sharp contrast to Design-Bid-Build, where the client's own design team and a separately-appointed contractor have to coordinate across an organizational boundary that Design and Build largely removes.
Designing a building so it can be easily reconfigured or repurposed for a different use later, rather than only ever serving its original function. A generous floor-to-floor height and a structural grid that doesn't fight future partition walls are both design-for-adaptability decisions - cheap to make at design stage, expensive to retrofit later.
Designing out health-and-safety risks at the design stage itself, rather than leaving the contractor to manage them once construction begins. It's the design-stage half of the CDM Regulations' logic - a designer choosing a lighter cladding panel that two people can lift safely, instead of one requiring a crane and a higher-risk lift, is design for safety in practice.
An agreed project milestone at which no further changes to a defined scope of the design are permitted, so downstream teams can proceed with confidence. Freezing a defined package (say, the building envelope) at an agreed LOD lets those teams commit resources without redoing work every time someone tweaks a wall.
A way to model and compare multiple design alternatives inside one project file. Revit's built-in tool for exploring several design alternatives - different lobby layouts, different facade treatments - inside a single project file, without duplicating the whole model. Elements get assigned to an Option Set (a group of mutually exclusive choices) and a specific Option within it; the rest of the model, outside any option set, stays the shared "main model" that every option shares.
This is genuinely different from comparing full design alternatives in generative or computational workflows - Design Options is specifically Revit's own, file-internal mechanism, mainly used for short-lived, small-scale comparisons during design development rather than large parallel-scheme studies.
A structured questionnaire-based tool (DQI) used to score a building design against functionality, build quality, and impact, gathering stakeholder input at defined project stages. DQI surveys are usually run at three points - early design, detailed design, and post-completion - letting a client, design team, and end users score the same project against the same criteria and see how perceptions shift as the building actually gets built. It's a softer, perception-based complement to the harder performance numbers a post-occupancy evaluation or building performance simulation produces.
A structured meeting or workflow where stakeholders examine the current model against requirements, standards, and coordination issues before design proceeds further. Increasingly run inside a common data environment or a viewer like Navisworks or BIM 360/ACC rather than around a printed drawing, a design review lets every discipline see the same federated model at once and log issues (often as BCF files) directly against the elements causing them.
The traditional procurement route where a client's design team completes the design first, contractors then bid competitively on it, and a separate contractor executes construction. Because the design and construction teams are separate organizations under Design-Bid-Build, model handover between them has to be explicit and well-documented (clear EIR/BEP requirements matter more here) rather than assumed - unlike Design and Build, where design and construction responsibility already sit inside one contract.
A pre-built, repeatable 2D drafting symbol (like insulation batting or a wood blocking section) placed inside detail views, distinct from a Filled Region's simple hatch fill. Where a Filled Region just fills a shape with a hatch pattern, a Detail Component is a genuine reusable family with its own geometry and behavior (it can flex, array, and carry parameters) - the right tool for anything that needs to repeat identically across many detail drawings, like a run of insulation or a standard flashing profile.
A Revit group made of 2D annotation and detail elements only, as opposed to a model group, which bundles real 3D geometry. A repeated typical detail - dimensions, tags, and 2D linework around a recurring construction condition - is a natural fit for a detail group, kept separate from the 3D model groups used for repeated physical assemblies.
Coarse, Medium, Fine
The view-specific display detail of an element - not to be confused with LOD. Detail Level (Coarse, Medium, or Fine) is a per-view Revit display setting that controls how much graphical detail an element shows: a wall at Coarse might draw as a single line, the same wall at Fine shows every layer of its construction. LOD describes how reliable and developed the underlying model data is - a real, project-wide, cross-software concept. Detail Level is purely about how that same element is drawn on screen in one particular view, and has no bearing on the model's actual information content. A wall can carry full LOD 350 data and still display at Coarse detail in a small-scale site plan.
A 2D-only Revit line visible in a single view, used for annotation rather than 3D geometry. A Detail Line is view-specific, 2D-only annotation geometry - unlike Model Lines, which exist in 3D and appear in every view that cuts through them. Detail lines are how a drafter adds hatching, poché, or extra graphic detail to one particular drawing without affecting the model itself.
Design for Manufacture & Assembly
Designing for modular off-site production. Instead of designing a building and then figuring out how to build it, you design for off-site manufacturing from the start: modular elements, prefabricated MEP racks, ready-made bathroom pods - factory-produced to high precision and rapidly assembled on site. BIM is a precondition here: the model must reach fabrication-level accuracy (LOD 400) so the factory can work directly from it.
Design (MicroStation native format)
The native CAD/BIM file format of Bentley Systems' MicroStation, roughly the Bentley-ecosystem equivalent of a DWG or RVT file. On infrastructure-heavy projects (rail, highways, utilities) it's common to find DGN files alongside RVT and DWG ones, since Bentley's tools are especially strong in that sector - IFC is usually the neutral bridge between the two ecosystems.
Organizing, versioning, and controlling access to a project's digital files and data (models, documents, images) - the digital counterpart to managing the physical asset itself. A CDE is the practical tool that implements digital asset management on a project; the discipline itself is broader, covering everything from naming conventions to who's allowed to overwrite which file.
A UK government publication guiding how digital and modern methods of construction should be applied on public-sector projects. It's the practical, project-delivery-focused follow-up to policy documents like the Golden Thread requirements - less a technical standard like ISO 19650 and more a playbook of recommended practices (twin models, platform approaches, manufacturing-led design) that public clients increasingly reference in their own requirements.
Ensuring information stays usable, accessible, and trustworthy over time - not just interoperable between systems today, but readable and reliable years or decades later. Interoperability solves "can Software A read Software B's file today," while digital continuity solves the harder problem of "will this asset information still be usable in 20 years, after the software that created it is gone." It's why long-lived asset owners increasingly prefer open, well-documented formats (IFC, COBie) over proprietary ones for anything meant to outlive the current toolchain.
Delivering a built asset's information as structured, usable digital data throughout its life - from brief to operation - rather than as paper documents handed over once at the end. It's the broader philosophy ISO 19650, the AIM, and the golden thread all serve - a building's information staying accurate, structured, and accessible for decades, not just accurate enough to get through handover.
A broader term than BIM, covering the use of digital data and processes across a project's engineering, not just its building information model. Common in infrastructure and government contexts (especially Australia, the UK, and increasingly used alongside BIM in buildings too), Digital Engineering treats the model as just one part of a wider digital ecosystem that includes GIS, sensor data, simulation, and analytics. In practice, most organizations use "Digital Engineering" and "BIM" close to interchangeably, with DE emphasizing the engineering-data pipeline over the modeling software.
Manufacturing building components directly from BIM model data, using CNC machines, robotic arms, or 3D printers instead of manual fabrication from 2D drawings. It's what makes DfMA actually work in practice - the model has to be accurate enough (typically LOD 400) that a factory machine can cut, mill, or print directly from it with no human re-drawing step in between.
Submitting and reviewing building permit applications using structured BIM data rather than paper or PDF drawing sets, so a regulator's software can automatically check compliance rules. Singapore's CORENET and several US and EU pilot programs already automate parts of plan checking this way - reading rule-based checks (like fire egress distances or accessibility clearances) straight out of the model's own data instead of a human reviewer measuring a PDF by hand.
Simulating a construction sequence, a site logistics plan, or a commissioning process virtually before it happens on site, using the model instead of trial and error in the field. A 4D sequence walkthrough, a crane-lift simulation, or a virtual commissioning run-through are all forms of digital rehearsal - catching a clash of trades, a blocked access route, or a startup-sequence error on screen instead of on site, where fixing it costs far more.
A daily log of site activity, weather, labor, and incidents kept in a digital tool instead of a paper notebook. It matters most when a dispute happens months later - a searchable, time-stamped digital record is far harder to challenge than someone's memory of what a handwritten diary said.
The continuous, traceable flow of data connecting a building's design, construction, and operational information across its whole lifecycle. A digital thread means every piece of information - from an early design decision to a sensor reading on an installed asset years later - stays linked and traceable back to its source, instead of getting recreated or lost at each project handover. It's the connective tissue that lets a digital twin actually reflect reality, rather than being a one-off snapshot.
A live virtual replica fed by real-world sensor data. A live virtual replica of a physical building, continuously updated with real-world data from IoT sensors and building management systems. Unlike a static BIM model, a Digital Twin evolves after handover - tracking energy use, equipment health, occupancy patterns, and maintenance needs in real time.
Digital Twins are the endpoint of the BIM lifecycle: the model doesn't get archived when the building opens. It becomes the operational intelligence platform for the building's entire lifespan.
A landlord's claim against a tenant for the cost of restoring a leased space to its required condition at the end of the lease. A model or survey documenting the space's condition at lease start versus lease end is the practical evidence behind a dilapidations claim - the same reality-capture and scan-to-BIM techniques used for new-building as-built surveys apply here too, just at the other end of the tenancy.
A chain of related linear dimensions in Revit placed and aligned together as one continuous run, rather than as separate, independent dimension lines. Adding or removing a witness line from an existing dimension string automatically keeps every other segment aligned - manually placing the same number of separate dimensions almost never lines up as cleanly.
A company that publishes free, finished Revit plugins - SheetLink, ParaManager, DiRootsOne and others - for bulk parameter editing, Excel round-tripping and data extraction. DiRoots tools are ready to install and use, in contrast to pyRevit, which is a platform for writing your own scripts. SheetLink handles two-way sync of Revit parameter data with Excel, ParaManager manages shared parameters in bulk, and DiRootsOne bundles several of them together. They cover the same "get data in and out of the model fast" need that a team would otherwise have to script by hand.
A UV grid applied to a mass or generic form's face, used to pattern and populate it with adaptive components. Once a surface is divided, an adaptive component family can be loaded onto it and repeated across every grid node automatically - a panelized facade of hundreds of subtly different double-curved panels is a classic use case. Grid spacing, rotation, and pattern type (rectangular, triangular, diagrid) are all adjustable after the fact without re-dividing the surface from scratch.
The discipline of managing document versions, approvals, and distribution so everyone works from the current issue. Document Control is the discipline - often a named role on larger projects - of managing version numbers, approval status, and distribution so nobody works from a superseded drawing or spec. A CDE automates most of it, but the underlying responsibility (who approves what, who gets notified of a new revision) still needs to be assigned to a person.
A hosted Revit family category that cuts an opening in a wall and fills it, sized and swung according to its type parameters. A door is always hosted to a wall - move or delete the host wall and the door goes with it. Its swing direction, opening side, and sill condition are controlled by instance flip controls and type parameters like width, height, and frame material, and it automatically cuts the wall's geometry wherever it's placed.
Digital Plan of Work
A digital, structured version of a project's stage-by-stage plan of work, linking each RIBA stage to the information and data drops it requires. Where a traditional plan of work is a document, a Digital Plan of Work is structured data - it ties each project stage (see RIBA Plan of Work) to defined data drops, responsibilities, and classification, so software tools can track what's due, from whom, and when, rather than a project team tracking it manually in a spreadsheet.
A Revit view with no connection to the 3D model at all - pure 2D linework, used for generic details that don't need to reference real model geometry. A standard flashing detail that applies the same way on every project is a natural fit here - unlike a callout view, it never updates from the model because it was never linked to it in the first place.
A tracked index of every drawing issued on a project, listing its current revision, status, and issue date. A Drawing Register is the master list of every drawing issued on a project - its number, title, current revision, suitability status, and issue date - kept so anyone can confirm they're working from the latest version. In a well-run CDE the register is largely generated automatically from metadata, but on smaller projects it's still often a maintained spreadsheet.
Using an unmanned aerial vehicle to capture site imagery or data - progress photos, photogrammetry, thermal scans - from the air. It's often the fastest way to feed photogrammetry with the volume of overlapping images it needs, especially across a large or hard-to-access site.
A drone-mapping platform that stitches aerial photos into orthomosaics and 3D site models for progress tracking. DroneDeploy is a drone-mapping platform that stitches aerial photos captured during a Drone Survey into orthomosaic maps and 3D site models, tracking earthworks volumes and overall site progress from above over time - a top-down complement to ground-level tools like OpenSpace.
A Revit MEP system family that routes air between mechanical equipment and air terminals, sized and routed with fitting logic similar to pipe. Ducts connect through connectors on mechanical equipment and air terminals, and Revit auto-generates fittings (elbows, tees, transitions) as runs are drawn or resized. Duct systems carry their own sizing and flow calculations, and clash detection against structure and other MEP systems is one of the most common coordination tasks built around them.
Design Web Format XPS
Autodesk's lightweight, compressed file format for sharing and marking up 2D and 3D design data without the original authoring software. It's Autodesk's answer to a universal, view-and-markup-only export - much smaller than a native RVT or DWG, viewable in free tools, and unable to be edited back into the source model. Useful for review packages sent to people who don't need (or shouldn't have) editing access.
Autodesk's native CAD drawing format, still the everyday language of 2D exchange. The native binary file format of AutoCAD, and by extension one of the most common formats for exchanging 2D drawing information in construction, even in a BIM-heavy project. Revit can export sheets and views to DWG for consultants who still work in 2D CAD, or to satisfy a contract requirement for DWG deliverables.
DWG is not a BIM format - it carries lines, arcs, and blocks, not parametric elements or rich data - so exporting to DWG is effectively a step down in information richness. It remains essential in practice because plenty of contractors, authorities, and sub-consultants still expect drawings in DWG rather than IFC.
Drawing Exchange Format
An open, text-based 2D CAD exchange format - the simpler, more universally readable cousin of Autodesk's native DWG format. Because DXF's structure is openly published and text-readable, it's the safer choice when exchanging 2D drawing data with software that may not perfectly support DWG's proprietary binary format - at the cost of larger file sizes and occasional loss of some DWG-specific formatting.
Computational Design
Automation and logic instead of clicks. Computational design defines geometry and data through logic and rules instead of clicks - Dynamo is the visual-programming tool of the Revit world (with Python or C# via the API for advanced users). Everyday uses: renaming hundreds of sheets at once, automated QA/QC checks, filling parameters from an Excel table. Generative design takes it one step further - the computer proposes and evaluates dozens of alternatives against goals you define.
A free, node-based visual programming tool for Revit, letting users automate repetitive modeling tasks and generate complex geometry without writing code. It sits at roughly the same level as Grasshopper does for Rhino - dragging and connecting nodes instead of writing scripts - and can read and write Revit parameters directly, making it a common bridge between generative design workflows and a live Revit model.
A vendor-neutral file format for storing point cloud data captured by laser scanners, designed so scans from different hardware can be shared and processed the same way. Before E57, every scanner manufacturer had its own proprietary point cloud format, making it hard to move a scan between different reality capture and BIM tools. It's now the closest thing the scan-to-BIM workflow has to a common exchange standard, alongside LAS for airborne and mobile LiDAR data.
Early Contractor Involvement (ECI)
A procurement approach where the contractor joins the project during design (rather than after it's complete), contributing buildability and cost input before drawings are finalized. ECI tries to capture some of Design and Build's early buildability input while keeping the client's own design team in control - the contractor reviews the developing model, flags constructability issues (see Constructability) early, and often firms up pricing before the client commits to a fixed-price contract.
A formal notice, required under NEC-family contracts, that either party must issue as soon as they become aware of a matter that could affect the project's cost, time, or quality. It's built into the NEC contract's collaborative philosophy - flagging a problem the moment it's spotted, before it becomes a compensation event, gives both parties a chance to jointly manage it down instead of arguing about it after the fact.
Earned Value Management (EVM)
A method for measuring project performance by comparing the value of work actually completed against what was planned and what was spent. It answers a sharper question than "are we on budget" - by comparing planned value, earned value, and actual cost together, it shows whether a project is both on schedule and on budget, or drifting on one while looking fine on the other.
A site assessment of habitats and protected species, required before development in ecologically sensitive areas. An Ecological Survey assesses a site for habitats and protected species - bats, newts, nesting birds - before development, and is often a precondition for planning approval in sensitive areas. Its findings can trigger seasonal work restrictions or feed directly into a project's Biodiversity Net Gain calculation.
Revit's mechanism for asking to borrow an element another team member currently owns in a worksharing session, instead of being blocked from editing it. If a modeler needs to edit an element someone else already owns, Revit sends that person an editing request they can grant or deny - a lightweight negotiation layer that lets a large team work on the same central model simultaneously without constantly locking each other out.
Exchange Information Requirements
The client's BIM brief - what they need and how. The document that starts every BIM project. The EIR is written by the client (employer) and defines exactly what information they need from the project team - in what format, to what level of detail, and at which project milestones.
Think of it as the client's BIM brief. It covers:
Everything in the BIM workflow flows from the EIR. Under the older UK PAS 1192 standard the same acronym stood for "Employer's Information Requirements" - ISO 19650 renamed it to keep the term procurement-neutral internationally, since it uses "appointing party" rather than "employer."
A Revit MEP feature grouping electrical devices together and connecting them to a specific panel, so load and wiring can be calculated and scheduled automatically. Without assigning devices to a circuit, Revit has no way to generate a panel schedule - it's the invisible link that turns a scattered set of light fixtures into an actual electrical system on paper.
A Revit family category for panels, transformers, and switchgear that circuits and conduit connect to as their power source. Electrical equipment families carry connectors that circuits and feeders attach to, and panel schedules are generated directly from what's connected to a given panel. Load and clearance requirements around this equipment are typically flagged early, since relocating it late in a project can cascade through every circuit routed from it.
A Revit view type showing a building or interior wall face-on, from a fixed direction - the standard way to document exterior facades and interior wall elevations. An elevation view is generated by an elevation marker placed in a plan and always looks in one fixed direction, unlike a section which can cut at any angle. Exterior elevations document the building envelope for planning and construction drawings; interior elevations do the same job for a single room's walls, showing finishes, casework, and fixtures at a glance.
The carbon emitted producing, transporting, and constructing a building's materials. The carbon emissions associated with a building's materials and construction process - extracting raw materials, manufacturing products, transporting them, and the construction work itself - as distinct from operational carbon, which comes from running the finished building. For a highly efficient modern building, embodied carbon can represent a larger share of lifetime emissions than operational carbon, simply because operational energy use has fallen so much.
A BIM model with accurate material quantities and types is the practical foundation for calculating embodied carbon: multiply each material's quantity (extracted the same way as any QTO) by its published carbon factor, and the total becomes a genuine design decision input rather than a guess made after the fact.
The total energy consumed extracting, manufacturing, and transporting a building material - a related but distinct measure from its embodied carbon. Embodied energy and embodied carbon usually rise and fall together, but not always - a material can be energy-intensive to produce while using a relatively low-carbon energy source, or vice versa, which is why sustainability assessments increasingly track both rather than assuming one predicts the other. It's typically reported in megajoules per kilogram of material, feeding the same kind of material-quantity data a Revit model already carries for carbon accounting.
The person appointed to administer a Design and Build contract on the client's behalf. An Employer's Agent is appointed to administer a Design and Build contract on the client's behalf - certifying payment, issuing instructions, and confirming practical completion - the JCT Design and Build equivalent of the Contract Administrator role used on traditional procurement.
The client's technical brief in a Design and Build contract, distinct from the EIR's information requirements. Employer's Requirements (ER) is the document a client issues in a Design and Build procurement setting out what they want built - performance standards, specifications, constraints - to which the contractor responds with their Contractor's Proposals. It's easy to confuse with EIR (Exchange Information Requirements), but the two cover different ground: ER defines the building itself, EIR defines the information deliverables about it.
Execution of steel structures and aluminium structures
The European standard governing the execution and CE marking of structural steel and aluminum, setting requirements for how fabricators must produce and document their work. A steel fabricator without EN 1090 certification simply can't legally supply structural steel into the European market - it's a hard compliance gate, not a voluntary quality mark.
Sustainability of construction works - Assessment of environmental performance of buildings
The European standard defining the methodology for assessing a building's environmental performance over its whole life cycle. It's the formal methodology behind a life cycle assessment - the standard that defines exactly which life cycle stages and impact categories a whole-life carbon figure actually has to account for.
Energy performance of buildings - Ventilation for buildings
The European standard for indoor environmental quality - thermal comfort, air quality, lighting, and acoustics - used to set design criteria for ventilation and building services. CIBSE guidance in the UK and EN 16798 across Europe cover much of the same indoor-environmental-quality ground, from two different institutional directions.
A simplified geometric representation Revit generates from a design model specifically for energy analysis - rooms and building shell only, stripped of unrelated detail. It feeds directly into building performance simulation tools like IES-VE or Autodesk Insight - a full architectural model has far more geometric detail than an energy simulation actually needs or can efficiently process.
Energy Performance Certificate (EPC)
A legally required rating (typically A-G) showing how energy-efficient a building is, needed before it can be sold, rented, or in some jurisdictions, occupied. Unlike BREEAM, LEED, or Passivhaus, which are voluntary certifications a client chooses to pursue, an EPC is often a hard legal requirement - and the same energy model or building performance simulation data used to chase a voluntary certification typically produces the EPC rating as a byproduct.
A real-time rendering plugin that turns a Revit model into an explorable 3D scene instantly. A real-time rendering plugin that runs directly inside Revit (and several other BIM tools), turning the model into a walkable, photorealistic 3D scene almost instantly - no separate export, no waiting for a render to finish. As you edit the model, the Enscape view updates live alongside it.
Its main value is communication: a client or contractor who cannot read a floor plan can walk through an Enscape view of the same design and understand it immediately. It has become close to a default expectation on client-facing Revit projects, the same way a rendered visual used to be a special, separately-commissioned deliverable.
A formal study of a project's likely effects on the environment, required for larger developments before planning consent. An Environmental Impact Assessment (EIA) is a formal study, required for larger or more sensitive developments, that documents a project's likely effects on ecology, noise, traffic, air quality, and more, along with the mitigation proposed for each. The resulting Environmental Statement is submitted alongside the planning application and can drive design decisions long before a model exists.
A site-specific plan controlling a construction project's environmental impact - noise, dust, water runoff, protected species and habitats. It sits alongside the site waste management plan as one of the two environmental documents most planning approvals now condition on.
Environmental, Social, and Governance Reporting
Corporate and investor-facing reporting on a building portfolio's environmental and social impact, increasingly sourced directly from BIM/asset data rather than compiled by hand. A property company reporting embodied and operational carbon across dozens of buildings to investors or regulators increasingly pulls that data straight from each building's Asset Information Model rather than commissioning a separate audit - another reason accurate, structured model data keeps paying off long after handover.
Eurocodes - European structural design standards
A family of European standards (EN 1990-1999) defining structural design rules - loads, materials, seismic design - that a structural analytical model must be checked against on projects following European practice. Eurocode 1 defines the loads, Eurocode 8 covers seismic design, and so on - a structural engineer sets up load combinations in a tool like Robot Structural Analysis according to whichever code governs the project's jurisdiction, Eurocode being the most common outside North America.
Extension of Time (EOT)
A formal contractual claim granting a contractor additional time to complete the works, usually due to a delay outside their control. A well-documented model and schedule history is exactly what an EOT claim needs to prove its case - showing precisely when a design change or a late information delivery actually pushed back the construction sequence, rather than the delay being the contractor's own fault.
Detailed, manufacturer-accurate MEP components in Revit - specific duct fittings, pipe couplings - used for fabrication-level detail instead of generic system families. A generic duct family is fine for design coordination; fabrication parts carry the real manufacturer data needed for digital fabrication, feeding straight into a factory's cutting and assembly process.
The ongoing operation, maintenance, and management of a building throughout its in-use lifecycle, once construction handover is complete. BIM's usefulness doesn't end at handover - a well-structured Asset Information Model, populated via COBie or similar, feeds directly into facilities management software so building owners can track assets, plan maintenance, and manage space without re-surveying the building. It's the single biggest reason large owners mandate BIM on their projects in the first place.
Revit Families
Revit's parametric building blocks. A family is a parametric component definition - a door, a column, a light fixture - with types (predefined size and property combinations) and instances (the actual placed elements). Revit has three kinds: system families (walls, floors, roofs - built into the project), loadable families (.rfa files you create or download), and in-place families (one-off elements modeled directly in the project). Mastering families is the single biggest step from "using Revit" to "controlling Revit".
The dedicated Revit environment for building parametric family content. The separate modeling environment inside Revit - opened by editing a family rather than a project - where Families actually get built: reference planes and lines first, then parametric geometry, types, and formulas layered on top. It looks similar to the main project environment but behaves differently in important ways, most notably that a family file has no worksharing and is designed to be flexed and tested in isolation before being loaded into a real project.
Comfort in the Family Editor is usually the clearest dividing line between someone who "uses" Revit and someone who can genuinely solve problems in it - most everyday frustrations with a missing or wrong component get fixed here, not in the project file.
A parameter defined inside a family, controlling its own geometry or behavior, that stays local to that family unless it's explicitly turned into a shared parameter. It's the family-editor-level counterpart to project and shared parameters - a door family's own "panel width" formula is a family parameter, and it stays invisible to schedules and tags outside that family until it's promoted to a shared one.
The starter file (.rft) chosen when creating a new Family in the Family Editor, which pre-configures its hosting behavior and category - distinct from a Project Template (.rte), which sets up an entire new project. Picking "Door" as a family template pre-wires wall-hosting behavior and standard door parameters, while picking "Generic Model face-based" sets up something that can attach to any surface - choosing the wrong family template at the start is one of the most common reasons a custom family behaves unexpectedly later.
FARO's software for processing and registering point cloud data from its own laser scanners - the direct competitor to Leica Cyclone. Which one a survey team uses usually just comes down to which brand of scanner they bought - the two ecosystems solve the same registration problem in largely the same way.
A roof accessory element that runs along a roof's edge - the vertical trim board a gutter typically attaches to. Fascia is placed by selecting roof or eave edges and follows their geometry automatically, the same way a Wall Sweep follows a wall's path - move or reshape the roof and the fascia updates with it. A Gutter is typically added the same way, hosted directly to the fascia rather than to the roof itself.
Filmbox (FBX) file format
A 3D interchange format, originally from Autodesk, widely used to move geometry, materials, and animation between BIM tools and real-time visualization/game engines. Revit can export directly to FBX, which is the format most visualization and game-engine tools (like Unreal Engine or Twinmotion in some pipelines) expect as input - useful when a model needs to go beyond a still rendering into an interactive walkthrough or VR experience.
Discipline models linked into one coordinated view. A combined model made up of separate discipline models linked together - the architect's model, the structural engineer's model, and the MEP engineer's model all viewed simultaneously. Nobody works in the same file; instead, each team works in their own model and the federated model is assembled for coordination reviews.
Federated models are used to run clash detection and to give all stakeholders a complete picture of the building.
The plan for how a project's models are split into manageable volumes and then linked back together into one coordinated whole. Also called a volume strategy, it sets out how models are segregated - typically by building, zone, and discipline - so multiple teams can model simultaneously without file-size or coordination problems, and then defines the hierarchy for linking those pieces back into federated models, up to a single master federated model for the whole project. Usually documented as part of the BIM Execution Plan.
International Federation of Consulting Engineers - standard contract forms
A widely used family of standard international construction contract forms (Red Book, Yellow Book, Silver Book), especially common on cross-border and international projects outside the UK/US. Each FIDIC "book" fits a different procurement model - the Red Book suits traditional Design-Bid-Build with an employer-designed project, the Yellow Book suits Design and Build, and the Silver Book suits EPC/turnkey projects - so which one a contract references says a lot about who carries design risk before a single clause is even read.
FIDIC Conditions of Contract for Construction
The most widely used contract form in the FIDIC family, for projects where the employer's own designer does most of the design and the contractor builds to it. It's the FIDIC equivalent of a traditional design-bid-build split - the Yellow Book, by contrast, is FIDIC's form for design-and-build-style contracts where the contractor designs too.
A construction field-management app for task tracking, punch lists, and plan markup on site. Fieldwire is a mobile-first field-management app used to track tasks, punch-list items, and drawing markups directly from a phone or tablet on site, keeping the office and the site crew looking at the same up-to-date plan set.
A view-specific 2D drafting element in Revit that fills a sketched boundary with a hatch or solid pattern - used for annotation, not for real building geometry. A filled region only exists in the view it was drawn in - it has no real-world thickness or 3D presence - which makes it the right tool for things like poché, paving patterns on a plan, or a highlighted zone that shouldn't affect quantities or schedules the way an actual model element would.
The final, agreed statement of exactly what a contractor is owed for a completed project, once every variation, claim, and adjustment has been settled. Agreeing the final account is often the slowest part of closing a project out - every change order, extension of time, and loss-and-expense claim has to be reconciled against the original contract sum before either party signs off.
Finite Element Analysis (FEA)
An engineering analysis method that breaks a structure into many small, simple elements to numerically calculate how it behaves under real loads and forces. A structural engineer takes the analytical model (see Structural Analytical Model) out of Revit into a dedicated FEA tool like Robot Structural Analysis, which subdivides members into a mesh of small elements and solves the physics for each one - the standard method behind every modern load case, deflection, and code-compliance check.
Dividing a building into fire-resistant zones so a fire stays contained in one compartment instead of spreading unchecked through the whole structure. Compartment walls and floors carry a fire-resistance rating and every penetration through them - a duct, a cable tray, a door - needs its own fire-stopping or rated assembly to preserve that boundary. In Revit, compartmentation is typically modeled as a dedicated set of fire-rated wall and floor types with their rating carried as a parameter, checkable against local fire codes.
A formal assessment identifying fire hazards in a building and the measures needed to control them, required for most non-domestic buildings in the UK. It's a live, building-specific document rather than a one-off design check - and for higher-risk buildings, it now has to stay current as part of the golden thread.
The specific fire-safety-related information about a building's design and construction that must be handed to the responsible person under UK building safety legislation. For higher-risk buildings this feeds directly into the golden thread and the building safety case - fire safety information can't be a static PDF handed over once, it has to stay accurate as the building changes over its whole life.
Regulatory Reform (Fire Safety) Order 2005
UK legislation placing a legal duty on whoever is responsible for a non-domestic building to carry out and act on a fire risk assessment. It's the legal requirement that makes a fire risk assessment mandatory rather than optional - the Building Safety Act added a further layer of duties on top of it specifically for higher-risk buildings.
A design-stage document setting out how a building's layout and systems achieve fire safety compliance. A Fire Strategy Report is produced early in design by a fire engineer, setting out how the building's layout, means of escape, compartmentation, and fire-safety systems work together to meet Building Regulations Part B. It's a living document, updated as the design develops, and increasingly expected to be traceable through a project's Golden Thread on higher-risk buildings.
A building certification focused on occupant health and wellbeing, similar in purpose to the WELL Standard but generally faster and cheaper to achieve. It's positioned as the more accessible alternative to WELL - less exhaustive documentation, but covering much of the same ground around light, air, and occupant comfort.
A report assessing a site's flood risk and the mitigation measures a design must include before planning approval. A Flood Risk Assessment (FRA) is a report, usually required by planning authorities, that evaluates whether a site is at risk from flooding and specifies the mitigation a design must include - raised finished floor levels, sustainable drainage, flood-resistant materials. It's typically commissioned early, since its findings can constrain site layout, floor levels, and even whether the site is developable at all.
A horizontal system family in Revit, sketched as a boundary and built from a layered structure, that forms the walkable surface of a level. A floor is sketched by drawing its boundary in plan and, like a wall, gets its layers - structural slab, insulation, finish - from its type. Floors can slope via shape editing, and they host railings, stairs, and other elements that need a horizontal reference.
A Revit view looking straight down at a level, cut at a defined height - the most common view type for documenting layout, walls, and room arrangement. A floor plan is automatically generated for every level in a project and shows whatever the View Range's cut plane passes through at that elevation - which is why elements above or below the cut plane appear, disappear, or show as dashed depending on that setting. It's the primary working view for most architectural and structural drafting.
A mathematical expression written into a family or shared parameter that automatically calculates one value from others, instead of requiring manual input. A door family's frame width might be written as a formula referencing the door's overall width plus a fixed offset, so changing one dimension automatically updates the other - the mechanism that makes a well-built parametric family flex correctly instead of breaking when a user changes an unexpected value.
A long-term procurement arrangement with a pre-selected panel of contractors or consultants, used to award multiple future projects without re-tendering each one individually. Common in public-sector work, a framework establishes standard rates and BIM/information requirements once, then individual projects ("call-offs") are awarded quickly against it - meaning a firm's BIM standards and templates need to be consistent enough to serve many different projects drawn from the same framework, not tailored to just one.
A free, open-source parametric 3D CAD application with a dedicated BIM workbench for architectural modeling. It's a smaller, less mature project than Revit or ArchiCAD, but it's a real, actively developed part of the same open-source push toward openBIM as BonsaiBIM.
A loadable Revit family category for freestanding items - desks, chairs, tables - typically face-based or level-hosted rather than wall-hosted. Furniture families are usually placed freely in plan rather than hosted to a wall or floor, though face-based variants can attach to any surface. They're a common target for schedules and material takeoffs on interior fit-out projects, where quantities and finishes need tracking room by room.
A real-time VR and 4D construction simulation tool that connects directly to Revit for interactive walkthroughs and construction-sequence visualization. Fuzor sits at the intersection of visualization and scheduling - a project team can walk through the model in VR while simultaneously scrubbing through the construction timeline, which makes it a popular choice for site logistics planning and stakeholder presentations that need to show both "what it looks like" and "when it happens" together.
Green Building XML
An XML schema for exporting a building's geometry and properties to energy-analysis software. gbXML is an XML-based schema for exporting a building's geometry, spaces, and construction properties from a BIM tool into dedicated energy-analysis software - the standard bridge between Revit's Energy Model and external tools like IES-VE, since gbXML carries the thermal and spatial data those tools need that a general-purpose format like IFC isn't optimized for.
A Revit workflow that automatically generates and evaluates many design options against defined goals and constraints, instead of a designer manually iterating one option at a time. You define the inputs (say, a site boundary and a program of rooms), the goals (maximize daylight, minimize travel distance), and the constraints, and generative design produces a range of viable layouts ranked against those goals - letting a team explore far more options than manual iteration would allow. It builds on the same underlying computational-design engine as Dynamo, but is packaged as a guided, goal-driven workflow rather than open-ended visual scripting.
Anchoring a model to real-world GPS coordinates so it sits correctly on a map. Setting a project's true real-world position - latitude, longitude, and true north - so the model sits correctly on a map and its solar and shadow studies calculate accurately for its actual location. Revit's Shared Site feature lets multiple linked projects agree on one common real-world anchor, which matters on large multi-building sites or infrastructure projects spanning a wide area.
Geolocation and shared coordinates solve related but different problems: shared coordinates get models to agree with each other, geolocation gets the whole project to agree with the real planet - both need to be right for a model's sun studies, site context, and GIS integration to actually mean anything.
The physical shape, dimensions, and spatial position of a BIM element - as opposed to the non-geometric data (properties, specifications) attached to it. Every BIM element carries two kinds of information side by side: geometric data (its 3D shape and location) and non-geometric data (everything else - manufacturer, fire rating, cost code). A model can look complete geometrically while its non-geometric data is still empty, which is exactly the gap an EIR is written to close.
Greenhouse Gas Protocol
The most widely used framework worldwide for measuring and reporting greenhouse gas emissions, splitting them into direct, energy-related, and full value-chain categories. Its Scope 1/2/3 split is what most net-zero targets and carbon accounting systems in construction are actually built around, even when the project itself never names the protocol directly.
Connecting a BIM model's detailed asset-level data with GIS's broader geographic and infrastructure context, so a building or asset can be understood in relation to its surroundings. A single building's BIM model is precise but zoomed-in; a city's GIS layer is broad but shallow on detail - integrating the two lets a utility company, for instance, see exactly which pipe inside which building connects to which street-level main.
Project-wide named values that can drive dimensions and formulas across a model. Named, reusable values (a length, an angle, a number, a yes or no) that live at the project level rather than inside a single family, and can be used to drive dimensions, constraints, and formulas anywhere in the model. Setting a "Standard Corridor Width" as a Global Parameter and tying every corridor dimension to it means changing the office standard once updates every corridor in the project instantly, instead of hunting down each one manually.
They are a lightweight entry point into the same "define it once, drive everything from it" thinking that parametric modeling and shared parameters are built on, without needing a Dynamo graph to set up.
GL Transmission Format
A lightweight open 3D format built for fast web and AR/VR viewing. An open, royalty-free 3D file format (maintained by the Khronos Group) designed specifically to load fast in web browsers, game engines, and AR/VR applications - which IFC was never built for. glTF strips a model down to lightweight geometry, materials, and textures, dropping the rich parametric and classification data that IFC carries.
In a BIM workflow, glTF is typically an export target at the end of the pipeline: a coordinated federated model gets converted to glTF so a client or site team can view it smoothly on a phone or in a VR headset, without needing heavyweight BIM software.
An unbroken, accessible record of a building's safety-critical information. A term that entered BIM vocabulary through UK building-safety reform (following the Grenfell Tower inquiry): the Golden Thread is the requirement that safety-critical information about a building - fire strategy, structural design, materials, later changes - stays accurate, accessible, and unbroken from design through construction and for the entire life of the building.
It is less a specific document than a principle: information created during design must not get lost or become out of date by the time a building is occupied. BIM and a well-run CDE are the practical tools that make a Golden Thread achievable - a spreadsheet in someone's inbox is not.
The UK public-sector policy version of Soft Landings, mandating operational performance review after handover. Government Soft Landings (GSL) is the UK public-sector policy that applies the general Soft Landings approach - involving the end-user team early and reviewing real building performance after occupation - as a mandatory requirement on government-funded projects, rather than an optional best practice.
A visual programming plugin for Rhino widely used for parametric and generative design in architecture and computational BIM workflows. Like Dynamo for Revit, Grasshopper lets designers wire together nodes instead of writing code to generate and control complex geometry - facades, structural optimization, form-finding - parametrically. It's especially dominant in early-stage conceptual design and competition work, where Rhino's freeform modeling is often preferred to Revit's more constrained tools.
A datum element marking a structural column line across a project, labeled and referenced the same way on every plan, section, and elevation. Like a level, it's a datum that only needs to be placed once and stays consistent everywhere - structural engineers in particular navigate a drawing set almost entirely by grid references rather than by room names.
A geotechnical survey of a site's soil and groundwater conditions, used to design foundations and assess contamination. A Ground Investigation Report documents a site's subsurface conditions - soil type and bearing capacity, groundwater level, contamination - gathered through borehole samples and lab testing. Structural engineers rely on it to size foundations, and it often surfaces risks (contaminated land, unstable ground) that reshape a scheme before design work goes far.
Guaranteed Maximum Price (GMP)
A contract arrangement in which the contractor guarantees the project's cost will not exceed an agreed ceiling, with any savings below it typically shared with the client. It shifts cost-overrun risk onto the contractor while still letting the client benefit if the actual cost comes in under the ceiling - a middle ground between a fixed lump sum and open-book cost-reimbursable contracts.
The process of a tenant returning a leased space back to the landlord at the end of a lease, typically obligated to restore it to an agreed condition. Handback is essentially the mirror image of the original handover - instead of a new asset moving from contractor to client, an already-occupied one moves from tenant back to landlord, and disputes over the space's condition at that point are exactly what Dilapidations claims are about.
The formal transfer of a completed asset - and its information - to its owner. The point where a project stops being a construction job and becomes an operating building: possession, and the associated information, formally transfers from the delivery team to the client or operator. In a BIM-driven project, handover is not just keys and a certificate - it is when the relevant parts of the PIM get filtered and delivered as the AIM, often packaged as COBie data, alongside warranties, manuals, and as-built records.
A handover that goes badly usually traces back to a poorly defined AIR at the start of the project - if nobody specified early on exactly what data the operator needed, there is no reliable way to assemble it under deadline pressure at the end.
A practical checklist confirming every deliverable required at handover has actually been provided - keys, manuals, certificates, the AIM itself. It's the last line of defense against the common failure mode where a client discovers, months later, that some promised document was never actually handed over.
The actual bundle of documents, manuals, and certificates delivered to a client at handover - what a handover checklist confirms was included. The checklist is the verification tool; the handover pack is the physical or digital thing being verified - an O&M manual, a building user guide, and a commissioning certificate are typical contents.
Training facilities staff and building occupants on how to actually operate and maintain a building's systems, delivered as part of handover. A building user guide is the reference document; handover training is the live session that actually makes sure someone read and understood it before the design team walks away.
A CDM-mandated document collecting the safety-relevant information a future owner, maintainer, or contractor needs to work on the building safely. Hazards that were designed out get recorded here too - if a structural element contains asbestos, or a roof has no permanent fall-arrest anchor points, this is the document that has to say so, following that information from design through the entire operational life of the building.
A family (like a door or window) that must be placed on and cuts into another element - the "host" - rather than standing on its own in free space. A door family is host-based on a wall (delete the wall and the door goes with it), while a face-based family can attach to any suitable surface, and a stand-alone family - like most furniture - needs no host at all. Choosing the right hosting behavior when building a custom family in the Family Editor determines how forgiving it is to place and move later.
Health and Safety Executive
The UK's national regulator for workplace health and safety, responsible for enforcing the CDM Regulations on construction sites. It's the body that can actually stop work on a site or prosecute a contractor over a health-and-safety breach - the CDM Regulations are the rules; the HSE is who enforces them.
A Revit plugin that exports model parameter data to Excel for bulk editing, then writes the edited values back into the model. Editing hundreds of door numbers or room names one by one inside Revit is slow and error-prone - Ideate BIMLink pulls that data into a familiar spreadsheet, where find-and-replace and formulas make bulk changes fast, then pushes the results back without anyone touching the model elements directly.
Information Delivery Specification
Machine-readable requirements checked automatically. buildingSMART's youngest standard, turning information requirements from Word documents into a machine-readable file. Instead of writing "every door must have a fire rating", an IDS file defines the requirement in a form software can check automatically against the IFC model - flagging every element that fails.
In practice: fewer arguments about "what was required", and quality control that becomes an automated report instead of a manual review.
Integrated Environmental Solutions Virtual Environment
A leading dedicated building performance simulation software, used for detailed compliance-grade energy, daylight, and thermal comfort analysis beyond what quick in-model tools provide. Where a quick Revit-native check answers "roughly how much energy will this use," IES-VE is built for the detailed, standards-compliant modeling a certification body or building regulator actually requires - geometry usually gets exported or linked from Revit rather than modeled a second time from scratch.
Industry Foundation Classes
Open file format for cross-software BIM exchange. The open standard file format for exchanging BIM data between different software platforms. IFC allows an architect working in Revit to send a model to a structural engineer working in Tekla or a contractor working in Navisworks - without losing information.
IFC is maintained by buildingSMART International and is the backbone of open BIM - the principle that BIM workflows should not be locked to any single vendor's software ecosystem.
Industry Foundation Classes 4.3
The IFC schema version that added full, native support for civil infrastructure - roads, railways, bridges, ports - alongside the buildings IFC already covered. Before 4.3, exchanging infrastructure data as open BIM meant stretching a buildings-focused schema to fit a road or a bridge; 4.3 gives alignments, road, rail, and other infrastructure disciplines their own proper IFC entities instead.
Issued For Construction Drawings
Drawing set formally released to the site team as the current build reference. The formal issue status marking a drawing as released to the contractor and site team as the authoritative version to build from - as opposed to earlier statuses like For Review or For Coordination, which are for internal checking only and were never meant to leave the design team's hands.
IFC drawings move through the same CDE approval gate as AFC Drawings, and on many projects the two labels describe the same milestone from two angles - IFC is what the site team sees stamped on the sheet, AFC is what the design team's issue tracking log calls the approval event. When a later revision supersedes an IFC set, the superseded drawings must be marked void immediately, since a subcontractor working from a stale IFC sheet is one of the most common, and costly, coordination failures on site.
The current major version of the IFC standard, with richer data than IFC2x3. The current major release of IFC, superseding the long-dominant IFC2x3 version. IFC4 added support for richer parametric relationships, better structural analysis data, infrastructure elements, and tighter alignment with openBIM workflows. In practice, IFC2x3 is still widely requested on many projects simply out of software-compatibility habit, so it is common to see an EIR specify exactly which IFC version - 2x3 or 4 - a project must use, since the two are not fully interchangeable.
Knowing to ask "which IFC version?" rather than assuming "IFC" means one single thing is a small detail that saves real coordination headaches.
A free, open-source software library for reading, writing, and processing IFC files - the engine underneath many openBIM tools, including BonsaiBIM. Most users never touch it directly - it's the underlying library developers build on, the same way a website's code depends on libraries a visitor never sees.
The fundamental choice between bringing external geometry into a Revit file as a static, disconnected copy (Import) or as a live, updatable reference (Link). An imported DWG or model is frozen the moment it's brought in - if the source file changes, nothing updates - while a Linked Model stays connected and refreshes automatically, which is why Linked Models are the standard for ongoing multi-discipline coordination, and importing is generally reserved for one-off reference geometry that will never need to update.
In-Place Family / Model In-Place
Geometry modeled directly inside a project for a one-off condition, rather than built as a separate, reusable Family - generally discouraged except for genuinely unique elements. An in-place model is quick to create but comes with real costs: it can't be shared or reused across projects, it tends to bloat file size more than an equivalent Family, and it doesn't flex the same way through Family Editor parameters - appropriate for a genuinely one-off sculptural element, but a common sign of a rushed workflow when used for anything repeatable.
The generic ISO 19650 term for any named, discrete unit of information - a model file, drawing, document, or schedule - stored and managed within a Common Data Environment. Rather than talking about "files" or "drawings" specifically, ISO 19650 uses "information container" as a vendor- and format-neutral label for any single piece of managed project information, so the same rules (naming, status, revision, approval) apply consistently whether the container is a Revit model, a PDF, or a spreadsheet.
A defined point at which information is formally shared between parties on a project - each one triggered by a data drop and governed by the requirements set out in the EIR. A tender submission, a stage-gate deliverable, and a final handover package are all information exchanges - not casual file-sharing, but a defined, checked, and recorded event. ISO 19650's whole CDE workflow exists to make each exchange auditable: who submitted what, when, and whether it passed the required checks.
The overarching discipline ISO 19650 codifies for organizing project information. The umbrella discipline that ISO 19650 exists to codify: planning, producing, reviewing, and securely sharing information throughout a built asset's life, using consistent processes rather than ad hoc habits that vary team to team. It is broader than "using BIM software" - information management covers the naming conventions, approval workflows, security classifications, and roles and responsibilities that make a CDE actually function as intended, rather than just being a shared folder with a fancier name.
Most of the acronyms in this glossary - EIR, BEP, AIR, PIM, AIM, LOIN - are all specific pieces of the information management framework that ISO 19650 defines.
The role responsible for managing information exchange within a Common Data Environment on behalf of the appointing party. Defined in ISO 19650, the Information Manager is a procedural role - not a design or coordination one - that governs the Common Data Environment (CDE), ensures information is exchanged according to the agreed protocol, and confirms deliverables meet the project's Exchange Information Requirements before they move between CDE states. The role has no responsibility for clash detection or design decisions; it exists purely to keep information management disciplined and auditable.
A broader term than "3D model" - the combined geometric and non-geometric data describing an asset, of which AIM and PIM are the two lifecycle-stage-specific versions. "Information model" is the umbrella term ISO 19650 actually uses - a federated model is one way to build it, but the information model also includes documents, schedules, and data that never appear in the 3D view. During delivery it's called a PIM; once handed over, it becomes the AIM.
The umbrella term for the family of documents (OIR, AIR, PIR, EIR) that define what information a party needs, at what level of detail, and when. Every "information requirements" document answers the same three questions - what, how detailed, and by when - just from a different vantage point: organizational (OIR), asset (AIR), project (PIR), or exchange with a specific supplier (EIR). Understanding the family as a whole makes each individual acronym much easier to place.
A pocket of data trapped inside one discipline's tools or one party's files, cut off from the rest of the project and unavailable to anyone who needs it elsewhere. An MEP consultant's spreadsheet of equipment data that never makes it into the shared model is a classic information silo - precisely the failure mode a CDE and a single source of truth are designed to eliminate.
A document listing the checks required at each stage of an activity and who must witness or approve them. An Inspection and Test Plan (ITP) lists, activity by activity, exactly which checks are required, at what stage, and who has to witness or sign off each one - a hold point that stops work until an inspector confirms it, versus a witness point that just requires someone present. It's the practical, activity-level tool that turns a project's Quality Plan into something a site team can actually follow.
Insurance-Backed Guarantee (IBG)
A warranty on installed work that stays valid even if the original contractor goes out of business, because an insurer stands behind it. A standard warranty is only as good as the company that issued it; an IBG solves the exact failure case where that company no longer exists to honor its own promise.
Integrated Project Delivery
A delivery method in which owner, designer, and contractor sign a single shared contract, aligning their interests and sharing risk and reward rather than negotiating against each other. Popularized by the AIA in the US, IPD is the delivery-method end state that target value design and co-location both support - the multi-party contract is what actually removes the incentive for any one party to protect its own margin at the project's expense.
The role that coordinates information exchange between different task teams working on interdependent parts of a project. The Interface Manager identifies where one task team's information depends on another's (for example, where structure and MEP models must align) and coordinates the exchange so nothing falls through the gaps between disciplines. It is a communication-heavy role, sitting alongside the Task Team Manager and Task Information Manager in a typical BIM task team structure.
Revit's built-in tool for finding geometric clashes between categories or elements inside the current model, distinct from full multi-discipline clash detection in a dedicated coordination tool. Interference Check is a quick, in-app sanity test - "does this duct hit this beam, within this one file" - while full Clash Detection in Navisworks or Solibri federates multiple linked models from every discipline and manages the resulting issues at project scale; most teams use both, at different stages.
The ability of different software to exchange BIM data without losing meaning. The broad goal that IFC, openBIM, and formats like glTF all serve: the ability for different software tools - made by different vendors, used by different disciplines - to exchange model data without losing or corrupting its meaning along the way. Perfect interoperability is genuinely hard: geometry usually survives a round-trip between programs, but rich data (parameters, classifications, relationships) is exactly what tends to get lost or mangled in translation.
It is worth treating as a spectrum rather than a yes-or-no property - "how interoperable" a given exchange actually is depends heavily on which specific software pair, which format, and which data you are asking about.
Internet of Things
Networked sensors and devices feeding a building's real-world data back into its digital model. Networked sensors and connected devices embedded throughout a building - occupancy sensors, temperature monitors, energy meters, smart lighting - that continuously feed real-world data back into digital systems. In a BIM context, IoT is what turns a static handover model into a live Digital Twin: instead of a one-time snapshot from handover day, the model keeps receiving real operational data for the rest of the building's life.
The practical value shows up in facilities management: an IoT-connected BMS can flag a failing piece of equipment before it breaks, or an energy manager can compare a building's real IoT-measured performance against the energy targets modeled during 6D design.
ISO 9001: Quality Management Systems - Requirements
The international standard for quality management systems - not BIM-specific, but commonly required of design/construction firms as proof of consistent process discipline before a BIM appointment is even considered. A client's tender documents often ask bidders to demonstrate ISO 9001 certification alongside their BIM capability - it's a baseline signal that an organization has documented, repeatable processes, which a BIM Execution Plan then builds project-specific information-management procedures on top of.
Building construction — Organization of information about construction works
The ISO standard defining the framework for construction classification systems like Uniclass and OmniClass. ISO 12006 sets out the framework construction classification systems are built on - how to structure tables for classifying elements, systems, spaces, and products so information stays consistent across a project. Uniclass and OmniClass are both implementations of this framework rather than competing standards built from scratch.
ISO 14001: Environmental Management Systems
The international standard for environmental management systems - often required in tenders alongside ISO 9001/45001, and distinct from a building's own certifications like LEED or BREEAM, which rate the building rather than the organization delivering it. Where LEED or BREEAM certify the completed building's environmental performance, ISO 14001 certifies the contractor or design firm's own environmental management processes - waste handling, resource use, pollution prevention on site - a different, organization-level layer of the same broader sustainability picture.
Greenhouse gases - quantification and reporting
The international standard for quantifying, monitoring, and reporting greenhouse gas emissions - the technical rulebook carbon accounting is measured against. Where the GHG Protocol is the widely adopted practical framework most organizations actually follow, ISO 14064 is the formal international standard version of the same underlying idea.
Industry Foundation Classes for data sharing in the construction and facility management industries
The ISO standard that formally defines IFC as the international data schema for openBIM exchange. ISO 16739 is the international standard that formally defines IFC (Industry Foundation Classes) - the data schema itself, not just the file format most people associate with the acronym. Software vendors certify their IFC export/import against this standard, which is what makes an IFC file from one authoring tool reliably readable in another.
International standard for BIM information management. The international standard for managing information over the whole life cycle of a built asset using BIM. ISO 19650 defines the principles and requirements for:
ISO 19650 is now the global reference standard for BIM, replacing earlier national standards like the UK's PAS 1192 series.
ISO 19650-1: Concepts and Principles
The foundational part of the ISO 19650 series - it defines the core concepts and vocabulary (CDE, information container, information requirements) that Parts 2 and 3 build on. ISO 19650-1 doesn't specify procedures itself - it's the shared glossary and conceptual framework the rest of the series depends on, covering ideas like the information container, the Common Data Environment's four states, and the general principle of managing information across an asset's whole lifecycle rather than just its design and construction phases.
Information management using BIM - Part 2: Delivery phase of assets
The part of ISO 19650 that sets out information management requirements during a project's design and construction (delivery) phase. Part 2 is the section of ISO 19650 most teams work with day to day - it defines the appointment process, EIR, BEP, MIDP/TIDP, and the CDE workflow that governs how information moves from tender through to handover. Part 3 picks up where it leaves off, covering the building's operational life.
Information management using BIM - Part 3: Operational phase of assets
The part of ISO 19650 covering information management once a building is in use, after project delivery is complete. Part 3 applies the same information-management discipline as Part 2 - appointments, information requirements, a CDE - but to facilities management, refurbishment, and day-to-day operation instead of design and construction, closing the loop between a project's Asset Information Model and its real operational life.
Information management using BIM - Part 5: Security-minded approach to information management
The part of ISO 19650 that sets out how to assess and manage the security risk of a project's sensitive information - the formal standard behind the general concept of security-minded BIM. It applies to projects where the information itself could be a security risk if it leaked - critical infrastructure, defense sites, high-profile buildings - requiring a documented sensitivity assessment before deciding how openly a CDE can actually be shared.
Information Container for linked Document Delivery (ICDD)
The ISO standard for packaging linked documents, models, and data from different sources into one exchangeable container. ISO 21597, known as ICDD, standardizes how to package a set of linked resources - IFC models, spreadsheets, PDFs, point clouds - from different authoring tools into one container with the relationships between them preserved. It targets a case a single IFC file can't solve: a federated deliverable made of documents that were never meant to merge into one model.
Information Delivery Manual
The international standard defining Information Delivery Manuals (IDM) - a structured way to describe exactly what information a specific process, like clash detection, needs at each project stage. An IDM maps a real business process - say, energy analysis at concept design - to the exact IFC data it depends on, which is what a Model View Definition (MVD) then implements in software terms. Where an MVD is the technical, software-facing output, ISO 29481's IDM is the process-facing document that explains why that data is needed in the first place.
Facility management — Management systems — Requirements with guidance for use
The ISO standard defining a management-system framework for delivering facility management services. ISO 41001 defines a management-system framework for how facility management services should be planned, delivered, and improved - covering the FM organization's processes rather than the physical asset itself, which is where ISO 55001 focuses instead. The two standards are commonly implemented together on large estates.
ISO 45001: Occupational Health and Safety Management Systems
The international standard for occupational health and safety management - increasingly required of contractors alongside ISO 9001, reflecting how seriously site safety is weighted in modern tenders. A contractor's ISO 45001 certification demonstrates a systematic approach to identifying hazards and reducing risk - the organizational counterpart to the design-side hazard elimination CDM Regulations require, closing the loop between safe design and safe execution.
ISO 55000: Asset Management - Overview, Principles and Terminology
The international standard for asset management systems - governing how organizations plan, operate, and maintain physical assets over their whole lifecycle, independent of any specific BIM standard. Where ISO 19650 governs how information is managed during design and construction, ISO 55000 governs the much longer asset-management phase that follows - aligning budgets, risk, and performance targets across an entire portfolio of buildings, not just a single project. A well-structured Asset Information Model (AIM) handed over at the end of a project is what lets an ISO 55000-compliant organization actually use that data operationally.
Asset management — Management systems — Requirements
The ISO standard specifying the auditable requirements an asset management system must meet for certification. ISO 55001 sets out the specific, auditable requirements an organization's asset management system must meet to be certified - distinct from ISO 55000, which explains the general principles and vocabulary behind asset management rather than a checklist to be audited against. A facilities team managing a built asset through its operational life treats 55001 as the compliance target.
Logging, assigning, and closing out coordination problems until they're resolved. The discipline of turning a coordination problem - a clash, a missing piece of information, a design conflict - into a tracked item with an owner, a status, and a resolution, instead of letting it live only in someone's meeting notes or memory. Issues are typically exchanged between teams as BCF files, or managed directly inside a CDE platform, and a well-run project reviews open issues on a fixed cadence until the count trends to zero.
The whole point of running clash detection and model coordination is worthless without disciplined issue tracking behind it - finding a hundred problems means nothing if forty of them quietly never get fixed.
Joint Contracts Tribunal
The most widely used family of standard building contracts in the UK, published by the Joint Contracts Tribunal, covering everything from small works to major design-and-build projects. Where NEC contracts are built around proactive, collaborative risk management, JCT contracts are the more traditional, still-dominant default most UK building projects actually use.
A general Revit tool that cleanly merges the shared surface between any two elements - not just walls - so one doesn't visibly overlap or double up with the other. Wall joins are the automatic, walls-only version of this at corners; Join Geometry is the manual tool for everything else - a column meeting a floor, a beam meeting a wall.
A lean philosophy of continuous, incremental improvement - small, ongoing changes rather than one big overhaul. It's the mindset underneath the whole lean construction movement - the same logic the Last Planner System applies week to week, just named at its most general.
A schedule-like view listing every keynote used on a sheet or in a project, alongside its full description. Where an individual keynote tag on a drawing just shows a short code, the keynote legend is the key that spells out what each code actually means - required on almost every construction drawing set that uses keynoting at all.
A numbered-note system linking drawing callouts to a master specification list. A documentation system where drawing notes reference a numbered code from a master keynote list (often tied to a classification system like MasterFormat) instead of writing free text directly on every sheet. A tag on a drawing shows just the code; the full note text lives in one central, editable list, so correcting a note's wording once updates it everywhere that keynote appears across the entire project.
It is essentially the annotation-level equivalent of shared parameters: one authoritative source of text, referenced everywhere, instead of the same phrase retyped independently on forty different sheets with forty chances to go slightly out of sync.
Keyhole Markup Language
An XML-based format for displaying geographic data, originally built for Google Earth, still widely used to share simple location and site-boundary data. It's a lightweight way to share "where is this site" with someone who has no GIS software at all - just Google Earth - unlike the richer, more structured data LandXML or CityGML carry.
An XML-based data exchange format for civil engineering and survey data - terrain surfaces, road alignments, pipe networks. It's the practical bridge between site-survey data and civil design tools like Civil 3D, doing for terrain and alignments roughly what IFC does for building elements.
LASer file format
The standard binary format for exchanging LiDAR point cloud data, most commonly used for airborne, mobile, and terrestrial survey scans. Maintained by the American Society for Photogrammetry and Remote Sensing, LAS is the format most site-survey and topographic LiDAR data arrives in before it's brought into a BIM or civil design tool - E57 covers much of the same ground for terrestrial laser scanning specifically.
Last Planner System
A lean-construction production planning method built around collaborative, reliable short-term commitments from the people actually doing the work - the "last planners" - rather than a top-down master schedule alone. Developed by the Lean Construction Institute, it works backward from milestone dates to weekly work plans that foremen and subcontractors actually commit to, then tracks a "percent plan complete" metric to catch unreliable commitments early rather than discovering a slipped schedule at the end.
The ISO 19650 role for the main delivery team appointed to lead the project. The organization appointed by the Appointing Party to lead delivery of the project - often the lead designer or the main contractor, depending on the procurement route. The Lead Appointed Party is responsible for producing the BEP in response to the client's EIR, and for coordinating the work of any Task Teams it appoints beneath it.
In a typical design-led project this role usually sits with the architect or lead consultant; on a design-and-build or contractor-led project it more often sits with the main contractor - the term itself is deliberately procurement-route-neutral, which is exactly why ISO 19650 uses it instead of a more specific job title.
Applying lean manufacturing principles - eliminating waste, maximizing value, improving workflow reliability - to how construction projects are planned and run. Techniques like the Last Planner System and target value design both come out of the lean construction movement, which reframes "waste" as anything that doesn't add value for the client - rework, waiting, and unreliable handoffs between trades, not just leftover material.
Leadership in Energy and Environmental Design
The most widely used North American green-building certification system. A point-based green-building rating system (from the US Green Building Council) that certifies a project across categories like energy performance, water use, materials, and indoor air quality, awarding a level from Certified up to Platinum. LEED does not require BIM, but in practice BIM makes pursuing it dramatically easier: energy analysis, daylight studies, and material quantities that LEED documentation demands can be extracted or simulated directly from the model instead of calculated by hand.
This is essentially what 6D BIM is for in practice - LEED (or its regional equivalents like BREEAM) is often the actual target that 6D energy and environmental analysis is being done to satisfy.
A special Revit view type that displays sample model elements and their symbols for documentation purposes, without belonging to a real location in the project. A Legend view can be placed on multiple sheets at once (unlike almost any other view type), which makes it the standard way to build a door/window schedule key, a wall-type legend, or a symbols key that needs to repeat identically across a whole drawing set.
A family instance placed in a legend view purely for display purposes, showing how an object looks without it being a real, schedulable element in the project. It exists purely for the legend view showing it - placing a chair as a legend component doesn't add a real chair anywhere else in the model or in any schedule.
A mandatory assessment of a building's water systems for the risk of Legionella bacteria growth. A Legionella Risk Assessment examines a building's water systems - tanks, pipework, cooling towers - for conditions that let Legionella bacteria grow, and is a legal requirement for anyone in control of a building's water supply. It's typically commissioned as the building approaches handover and repeated periodically once it's in operation, feeding into the Building User Guide's maintenance regime.
Leica Geosystems' software for processing and registering point cloud data captured by their own laser scanners. A raw laser scan doesn't arrive ready to use - Cyclone is where multiple individual scans get aligned into one clean, registered point cloud before it's exported to E57 or brought into a scan-to-BIM workflow.
A closeout document capturing what went well and what went wrong on a project, so the next one doesn't repeat the same mistakes. It's the single most commonly skipped document on this list - everyone agrees it's valuable, and it's still the first thing dropped when a project team moves straight on to the next job.
A pre-contract document in which a client authorizes a contractor to begin limited early work, before the full contract is signed. It lets long-lead procurement or early site work start without waiting for every contract clause to be finalized - useful for keeping a schedule moving, but risky if it's used to avoid agreeing terms rather than genuinely speed things up.
The horizontal reference planes in Revit - typically one per building story - that floors, walls, roofs, and nearly every other element attach to and measure from. Levels are one of the very first things set up in any Revit project, and almost everything else depends on them: worksets, phasing, schedules, and family placement all reference a level, directly or indirectly. Getting levels wrong early on is one of the most common causes of frustrating rework later.
Life Cycle Assessment (LCA)
The methodology for calculating a building's total environmental impact across its whole life - material extraction, construction, operation, and demolition - which embodied and whole-life carbon figures are the output of. LCA is the calculation framework itself (defined by standards like EN 15978), while embodied carbon and whole-life carbon are the specific numbers it produces - a Revit model's quantities and material assignments are what actually feed an LCA tool, making accurate material data entry a sustainability task, not just a documentation one.
The set of design requirements protecting occupants during an emergency - egress routes, fire ratings, compartmentation, and detection and alarm systems. Life safety spans multiple disciplines at once: architecture sets egress widths and travel distances, structural design determines how long a building stays standing in a fire, and MEP handles detection, alarm, and smoke-control systems. In Revit, fire-rating parameters, room-based egress calculations, and life-safety plan views all draw from the same underlying model data.
Revit's setting controlling how thick or thin each category of line prints and displays, at each view scale - part of an office's Object Styles and graphic standards. A wall's cut line needs to read heavier than a hidden line behind it at every scale a drawing might print at - line weights are what make that graphic hierarchy consistent across a whole set of sheets instead of being adjusted view by view.
Revit Links
Separate model files referenced into a project, kept live and update-able. The mechanism for bringing a whole separate model - another discipline's Revit file, a site survey, a consultant's model - into a project as a live reference, without merging the actual data together. Unlike worksets, which divide ownership within one shared central model, Linked Models are entirely separate files: the architect links the structural engineer's model to coordinate against it, but each team still owns and edits their own file independently.
Getting links positioned correctly depends entirely on shared coordinates being set up right - a link with the wrong coordinate system will look fine in isolation and be meters off once brought into the host model.
A pre-agreed daily or weekly financial penalty a contractor owes the client for every day a project runs late beyond its contracted completion date. Liquidated Damages are the financial mirror of an Extension of Time - if a delay is the contractor's fault, damages start accruing; if a valid EOT is granted instead, the completion date itself moves and damages don't apply, which is exactly why the underlying schedule and change documentation matters so much to both sides.
Level of Accuracy
A measure of how geometrically accurate and reliable a model element's captured dimensions are, distinct from how detailed it is (LOD). Defined by the U.S. Institute of Building Documentation, Level of Accuracy grades reality-capture data (like scan-to-BIM output) by measured tolerance - how close the model geometry is to as-built reality - which is a genuinely different question from Level of Development's "how much information does this element carry." A highly detailed element can still have low positional accuracy, and vice versa.
The predefined sets of simultaneous loads (dead, live, wind, seismic, in various factored ratios) a structural model must be checked against to confirm it's safe under every realistic scenario. A structural model rarely fails under any single load type alone - the dangerous scenarios are combinations, like peak wind load coinciding with full occupancy live load - which is exactly why building codes mandate checking dozens of specific load combinations rather than each load type in isolation, a process modern Revit-to-Robot workflows can automate.
A personal working copy of a workshared Revit project, saved on an individual's own machine, that periodically synchronizes with the central model. Every team member on a workshared project works inside their own local file rather than the shared central model directly - this keeps the file responsive and lets each person edit their own worksets without waiting on others, syncing changes back and forth via Synchronize with Central.
Level of Development
How detailed and reliable a model element is. LOD defines how detailed and reliable an element in the BIM model is at a given stage. It answers the question: "How much can I trust this model element, and what information does it contain?"
The standard LOD scale runs from 100 to 500:
| LOD | Stage | What it means |
|---|---|---|
| 100 | Concept | Element exists as a symbol or mass. Size and location are approximate. |
| 200 | Schematic Design | Generic element with approximate geometry and size. |
| 300 | Design Development | Specific geometry, exact dimensions, location, and orientation. |
| 350 | Construction Documents | Includes connections to adjacent elements. Ready for coordination. |
| 400 | Fabrication | Detailed enough for manufacturing and assembly. |
| 500 | As-Built | Verified in the field. Represents the building as actually constructed. |
LOD is used in the BEP to specify what level each model element must reach at each project milestone.
LOD 100–500 at a glance
LOD 100 Conceptual - generic massing or symbol
LOD 200 Approximate geometry - rough size, shape, location
LOD 300 Precise geometry - accurate size, shape, location, quantity
LOD 350 Like 300, plus interfaces with other building systems
LOD 400 Fabrication-ready - detailed for construction & installation
LOD 500 As-built - field-verified actual size, shape, location
Level of Information
How much non-graphic data an element carries. Often paired with LOD. While LOD describes geometric detail, LOI describes the non-graphic data attached to an element - properties, specifications, material data, performance values.
A door at LOD 300 has accurate geometry. The same door with high LOI also has a fire rating, acoustic rating, hardware specification, and manufacturer's product code. Both dimensions matter for handover and facility management.
Level of Information Need
Exactly what information is needed, for whom, and when. The newer, ISO 19650-era term that is gradually replacing the LOD/LOI pair in specifications. LOIN flips the question around: instead of asking "what LOD should this element reach?", it asks who needs which information, for what purpose, at which milestone - and requires exactly that, no more.
LOIN is defined in the European standard EN 17412-1 and covers three kinds of content:
The goal is to stop over-modeling: information nobody asked for costs time and money to produce and maintain.
A short-term rolling schedule (typically 2-6 weeks) used in lean construction to plan the work that's actually about to happen. A Look-Ahead Schedule is a short-term rolling plan - usually two to six weeks - that breaks the master programme down into the specific tasks each trade needs to prepare for right now, checking that materials, labor, and prerequisite work are actually ready. It's the core planning tool behind the Last Planner System.
A contractual claim for a contractor's direct financial loss caused by a client-side delay or disruption. Loss and Expense is a contractual claim a contractor can make for direct financial loss - idle plant, extended preliminaries, lost productivity - caused by a matter the client or their team is responsible for, submitted alongside or separately from an Extension of Time claim for the schedule impact of the same event.
Real-time rendering and visualization software popular for its fast setup and one-click Revit import, used to turn a model into photorealistic stills and walkthroughs. Compared to Enscape or Twinmotion, Lumion is used more often for final marketing-quality stills and animations than live design-review walkthroughs - a common workflow is modeling in Revit, then exporting to Lumion specifically for the polished renders a client presentation needs.
The single, authoritative version of a piece of information (a supplier's name, a room number, an asset ID) that every system and document is expected to reference rather than re-enter. Master data is what keeps a room number or asset tag consistent across the BIM model, the CDE, the FM system, and every schedule derived from them. Without a clear master data source, the same asset ends up with three slightly different IDs in three different places - exactly the inconsistency a single source of truth is meant to prevent.
The North American classification standard organizing specifications by construction division. The North American counterpart to Uniclass - MasterFormat (published by CSI, the Construction Specifications Institute) organizes construction information into numbered divisions, like Division 08 for Openings or Division 23 for HVAC. It is primarily a specifications-writing standard rather than a full BIM classification system, but it shows up constantly in US and Canadian projects as the backbone for organizing specification sections, and its division numbers often get mapped onto model parameters for consistency between the drawings and the specs.
Where Uniclass dominates UK/international projects, MasterFormat is what you will meet on North American ones.
An annotation marking where a large floor plan is split across multiple sheets, showing where each sheet continues on another. On a large building where one floor doesn't fit on a single sheet at a usable scale, it's the annotation that keeps someone reading sheet 3 from getting lost about where sheet 4 picks up.
Keeping a digital record of a building material's composition, origin, and condition, so it can be identified and reused when the building is eventually deconstructed. It's what turns deconstruction from a hopeful idea into a practical one - a demolition crew can't easily reuse a beam whose material grade and history nobody actually recorded.
A Revit schedule that reports the quantities of specific materials (concrete volume, paint area, floor finish area) rather than counting whole elements the way a normal schedule does. Where a door schedule counts doors, a material takeoff can report the total area of a specific paint finish across every room that uses it - directly feeding a bill of quantities without a separate manual measurement pass.
The Revit library of surface appearance, physical, and thermal properties assigned to model elements. Materials in Revit define how an element looks in a render (appearance asset), behaves structurally (physical asset), and performs thermally (thermal asset) - all three bundled under one named material that can be assigned to a wall layer, a family, or a whole category at once. Material Takeoff schedules pull quantities straight from these assignments.
A 3D-camera reality-capture platform that produces walkable virtual tours and a basic point cloud/mesh, widely used for quick existing-conditions documentation. Compared to a survey-grade laser scanner, a Matterport camera is faster and cheaper to operate but less precise - a common workflow for smaller renovation projects is a quick Matterport scan for a visual walkthrough and rough measurements, reserving a full laser scan for anything requiring true as-built modeling accuracy.
Model Element Author
The task team or party responsible for authoring a specific model element, recorded so everyone knows who to ask about it and who's accountable for its accuracy. On a coordinated, multi-discipline project, it's not always obvious who "owns" a given wall or duct in the federated model - the Model Element Author designation (often a code or abbreviation on the element itself) removes the ambiguity, tying every element back to the specific task team responsible for its geometry and data.
The continuous, protected path a building occupant follows from any point inside to a safe exit outside - corridor, stair, and exit door all included. A means of egress is checked as one continuous chain, not element by element - a perfectly rated fire door means nothing if the corridor leading to it is too narrow or the travel distance to reach it is too long. Revit models can tag travel distances and run egress-width checks directly against room and corridor geometry as a design develops.
A Revit MEP family category for HVAC equipment - air handling units, chillers, fans - that ducts and pipes connect to. Mechanical equipment families carry connectors that ducts and pipes attach to, and their placement drives flow and capacity calculations for the systems routed to them. They're typically scheduled with electrical load and clearance requirements alongside their mechanical specs, since coordination around them spans multiple disciplines.
A voluntary, non-binding dispute-resolution process where a neutral mediator helps parties negotiate their own settlement, rather than imposing a decision. It's the least formal of the three main dispute routes - cheaper and faster than adjudication or arbitration, but only works if both sides genuinely want to reach an agreement rather than win an argument.
Mechanical, Electrical & Plumbing
The building services disciplines. The engineering disciplines that handle a building's services: HVAC systems, electrical distribution, plumbing, fire protection, and more. MEP models are among the most complex in a federated BIM workflow because the systems they contain must be coordinated against the structure and against each other.
In Revit, MEP work is done in Revit MEP - a discipline-specific configuration of the same platform used by architects and structural engineers.
Data that describes other data - a file's author and creation date, or an object's classification code, rather than the file or object's actual content itself. A door family's geometry is data; the fact that it was last modified on a specific date, by a specific person, tagged with a specific Uniclass code, is metadata - exactly what a CDE's audit trail and a data dictionary manage.
A construction document describing exactly how a specific task or work sequence will be carried out on site, including safety controls and equipment. Where a schedule (like a 4D sequence) says when work happens, a Method Statement explains how - the actual steps, plant, and safety measures a crew will follow for a task like a crane lift or a concrete pour, often reviewed alongside the model to confirm the sequence is physically achievable.
Bentley Systems' CAD/BIM authoring platform, widely used on infrastructure, rail, and utilities projects as an alternative to the Autodesk ecosystem. Where Autodesk's tools dominate buildings, Bentley's MicroStation and its OpenX applications (OpenRoads, OpenBridge) are especially common in civil infrastructure - the two ecosystems meet on the same project through IFC exchange rather than either one replacing the other.
Information Delivery Plans
The delivery schedule of the information. Two documents from the ISO 19650 world that live alongside the BEP. A TIDP (Task Information Delivery Plan) is one team's delivery plan: which files and models that team provides, when, and at what level of information. The MIDP (Master Information Delivery Plan) combines all TIDPs into a single project-wide delivery plan - the schedule of the information, not of the construction.
If the EIR says "what", the MIDP says "who and when".
The act of creating and building up a BIM model's geometry and data inside an authoring tool like Revit, as opposed to coordinating, reviewing, or federating models made elsewhere. Revit, ArchiCAD, and Tekla Structures are authoring tools; Navisworks and Solibri are not - they federate and review what authoring tools already built. Knowing which category a piece of software falls into explains why a clash report from Navisworks still has to be fixed back in the authoring model, not in Navisworks itself.
The ongoing cycle of merging, reviewing, and resolving issues across discipline models. The ongoing, cyclical process that clash detection is just one part of: regularly merging discipline models into a federated model, reviewing it (visually and through automated checks), logging every problem found as a tracked issue, assigning it to whoever needs to fix it, and confirming the fix in the next cycle. A single clash-detection run is a snapshot; Model Coordination is the repeating weekly or biweekly rhythm that keeps a project's models converging toward a buildable, conflict-free design instead of diverging further apart.
Issues are typically tracked with BCF files so every team can open exactly the same problem in their own software, at the exact camera angle and element it was found.
A single discrete component within a BIM model that represents a real physical or spatial part of the building. Walls, doors, ducts, and rooms are all model elements - the basic building blocks that carry both geometry and data inside an information model. Understanding "model element" as the generic unit is what makes concepts like Level of Development and Model Element Author meaningful, since both are defined per-element, not per-model.
A Revit feature that bundles a set of elements together so they can be copied, placed, and updated as one unit across a project. Unlike a Family, which is a single reusable component, a Group bundles multiple existing elements (say, a hotel room's walls, door, and furniture) into one placeable unit - editing one instance of the group can propagate to every copy, which makes it a fast way to repeat identical layouts across a floor or a whole tower.
The overall technical condition of a model file - its file size, warning count, and how much unused or corrupted data it's carrying - independent of whether its design content is any good. A model can be brilliantly designed and still be unhealthy - hundreds of unresolved warnings, bloated by years of unpurged families, slow to open for everyone on the team. Regular audit and purge passes are the routine maintenance it actually depends on.
Lines drawn directly in 3D model space in Revit, visible in every view that shows that part of the model - unlike detail lines, which exist only in the single view they're drawn in. A model line drawn on a site plan to mark a property boundary shows up in a 3D view and a section too, since it's real model geometry - a detail line doing the same job would only ever appear in that one plan view.
A structured check that a BIM model meets the agreed standards - naming, LOD, classification, data completeness - before it's issued or federated with others. It's usually run automatically through rule-checking software (Solibri, Navisworks, or a custom IDS check) rather than manually, catching things like missing parameters or elements on the wrong workset before they reach a federated model and cause a much more expensive problem downstream.
Deriving a cost estimate directly from a BIM model's own quantities and data, rather than measuring drawings manually to produce a bill of quantities first. It's the practical outcome quantity surveyors are aiming for when they push for well-structured, LOD-appropriate models - the more reliable a model's quantities are, the less manual re-measurement an estimate needs.
Modern Methods of Construction (MMC)
An umbrella term for off-site, factory-based, and technology-driven construction approaches - modular units, panelized systems, digital fabrication - as an alternative to traditional on-site building. Modular construction and DfMA are two specific approaches that sit under this wider umbrella - MMC is the category the UK government and industry actually use when discussing the shift away from traditional building methods as a whole.
Building large sections off-site in a factory, then assembling them on site. A construction method where large sections of a building - entire rooms, bathroom pods, structural modules - are manufactured complete in a factory and transported to site for assembly, rather than built piece by piece on location. It is the physical, large-scale end of the DfMA spectrum: instead of individual prefabricated components, whole volumetric chunks of the building arrive ready or near-ready.
BIM is close to a prerequisite for modular construction at any real scale: the factory needs LOD 400 fabrication-level model accuracy to manufacture modules that will actually fit together correctly on site, since there is little room to "figure it out" once a module has already left the factory.
The structural framing member that divides a curtain wall into individual panels - vertical, horizontal, or angled. Mullions in Revit are placed automatically along a curtain wall's grid lines and can be swapped for different profile types - rectangular, L-shaped, circular - without touching the grid layout itself. Multi-loop mullion profiles let a single mullion carry a more complex cross-section than a simple extruded shape.
A single Revit tag family that can label elements from several different categories with one shared style. A Multi-Category Tag is a single tag family that can label elements from several different categories - furniture, casework, specialty equipment - sharing one visual style, instead of needing a separate dedicated tag family for every category a drawing might contain.
Model View Definition
A defined subset of the IFC schema tailored to a specific exchange use case, so software only has to implement the parts of IFC that use case actually needs. The full IFC schema is huge - an MVD narrows it down to exactly what's needed for one workflow, such as "Coordination View" for clash detection or "Quantity Take-off View" for QTO, so software vendors can certify support for a specific, testable subset instead of all of IFC at once. buildingSMART maintains the official MVDs alongside the IFC standard itself.
Autodesk Navisworks
Autodesk's model-review and coordination tool for federated BIM models. Autodesk's dedicated tool for reviewing large, federated BIM models from multiple disciplines and multiple software packages at once. Navisworks aggregates models (Revit, IFC, DWG, and more) into a single lightweight federated view, runs clash detection, drives 4D construction sequencing, and manages coordination issues, often exchanged as BCF files with the design team.
It is not a modeling tool - nothing gets designed in Navisworks - it is where coordination and construction planning happen once the discipline models exist. On many contractor-led projects, Navisworks (or a competitor like Solibri) is where the "real" coordination meeting actually happens.
National Building Specification
A UK-origin digital specification platform and standard specification library that links written performance/product requirements directly to BIM model objects. NBS specifications are traditionally the detailed written document that sits alongside drawings and the model, spelling out exactly which product, performance standard, or workmanship quality is required for each element. Modern NBS tools (like NBS Chorus) link that text directly to BIM objects by classification code, so a change to a spec section can be traced straight back to the model elements it governs.
New Engineering Contract, 4th edition
The current edition of the NEC family of construction contracts, built around proactive collaboration and early problem-flagging rather than after-the-fact dispute mechanisms. Early warning notices and compensation events are its two signature mechanisms - the whole contract is designed around surfacing problems while they're still small and cheap to fix.
A family loaded inside another family, sharing or exposing its own parameters. A family loaded inside another family - a handle family nested inside a door family, a hinge nested inside a window - letting complex components be built out of smaller, independently maintained pieces rather than one monolithic geometry blob. The parent family can expose (or "shared") the nested family's parameters so they still appear and schedule correctly at the project level.
Nesting is what makes large, realistic families genuinely manageable: update the handle family once, and every door family that nests it picks up the change, rather than needing forty separate handles remodeled by hand.
Net Zero Carbon
A building whose carbon emissions are reduced as far as possible and offset for the rest. A target where a building's carbon emissions - from both its operation (energy use) and its construction (embodied carbon) - are reduced as far as practically possible, with any unavoidable remainder balanced out through offsets or carbon removal, so the net contribution to atmospheric carbon is zero. "Net zero operational carbon" and "net zero whole-life carbon" are meaningfully different, narrower and broader claims, and the distinction matters when a client asks for one specifically.
BIM's role is mainly in the "reduce as far as possible" part: 6D energy analysis and embodied-carbon calculation from model quantities are what let a design team actually test how close to net zero a design gets, long before construction starts.
Project information management software that organizes and tracks correspondence, RFIs, and submittals across a project's full email and document trail. Rather than hunting through email threads to find who answered a specific RFI, Newforma indexes all project communication in one searchable place - a workflow layer that sits alongside, not inside, the BIM authoring tools.
The UK's most widely used technical standards and warranty requirements for new-build residential construction. NHBC Standards are the technical requirements a new-build home must meet to qualify for an NHBC Buildmark warranty - the most widely used new-homes warranty in the UK - covering everything from foundation design to internal finishes, and referenced constantly by housebuilders alongside Building Regulations compliance.
A report predicting a proposed development's noise impact and the mitigation needed to meet limits. A Noise Impact Assessment predicts the noise a proposed development will generate - or be exposed to, from nearby roads or industry - and specifies the mitigation needed to stay within acceptable limits. It's a common planning-application requirement, with construction-phase noise typically governed separately by BS 5228.
A formal record of work that fails to meet the specification, tracked through investigation to resolution. A Non-Conformance Report (NCR) formally records work that fails to meet the specification or an Inspection and Test Plan's requirements, capturing what went wrong, its cause, and the corrective action agreed before the work can proceed or be accepted. It's the paper trail Root Cause Analysis draws on when the same defect keeps recurring.
The information attached to a model element that isn't shape or position - specifications, cost, warranty, manufacturer, performance data. A door's 3D geometry tells you almost nothing useful for facilities management or costing on its own; its non-geometric data - fire rating, hardware set, supplier, warranty period - is what actually gets used downstream by schedules, COBie exports, and FM systems. BIM's real value over plain 3D modeling comes almost entirely from this layer.
A contractual mechanism transferring a design consultant's appointment from the client to the contractor partway through a project, common in Design and Build procurement. An architect appointed directly by the client during early design can get "novated" to the contractor once construction starts - the same firm keeps working on the same model, but their client relationship and reporting line legally switches, which can quietly change whose information requirements actually take priority.
The legal document that formally transfers a design consultant's contract, and their obligations, from the client to the contractor - the paperwork behind novation. It's what actually makes a design-and-build novation real - without a signed novation agreement, the consultant technically still answers only to the original client.
New Rules of Measurement
The UK quantity-surveying standard for measuring and costing construction work. A suite of standards (from the RICS, the Royal Institution of Chartered Surveyors) that define exactly how to measure and cost construction work consistently, across three volumes covering cost planning, detailed measurement, and maintenance costs. NRM is the rulebook that makes QTO and 5D meaningful in practice - it defines what actually counts as "one unit" of a wall, a door, or an excavation, so quantities extracted from a BIM model can be compared and costed consistently between projects and quantity surveyors.
Without a measurement standard like NRM behind it, a model-derived quantity takeoff is just a number - NRM is what makes it a trustworthy one.
Operations and Maintenance Manual
The handover document set explaining how to run, maintain, and service a completed building's systems and equipment. Traditionally a mountain of PDFs handed over in a box at the end of a project, the O&M Manual's content is increasingly pulled directly from BIM model data - maintenance schedules, warranty periods, spare-parts lists - so facilities managers get structured, searchable information instead of a filing cabinet to dig through.
A simple, widely-supported 3D geometry file format, originally developed by Wavefront Technologies, that stores mesh shapes, texture coordinates, and materials without any BIM-style parametric data. It's one of the oldest and most universally supported 3D formats, which is exactly why it's still used for moving simple mesh geometry into renderers, game engines, or 3D printing workflows where FBX or glTF might carry more than's needed.
A curated, reusable collection of BIM objects (families) that meet a consistent naming and classification standard, so they can be safely reused across many projects. BS 8541-1 is exactly the kind of standard a well-run object library is built against - without it, a library becomes a folder of files with inconsistent names nobody trusts enough to reuse.
The project-wide setting controlling the default line weight, color, and pattern for every model category - walls, doors, furniture - before any view-specific override is applied. It's the base layer underneath visibility/graphics overrides and view templates - change a category's line weight in Object Styles and it updates everywhere by default, unless a specific view has already overridden it.
The BIM approach of building a model from smart, data-carrying objects (walls, doors, ducts) instead of dumb lines and arcs, so each element knows what it is, not just what it looks like. A CAD line representing a wall is just geometry; a BIM wall object knows its own type, fire rating, and cost - and updates every plan, section, and schedule at once when it changes.
Organizational Information Requirements
The highest-level information needs - what the whole organization must know to run its business. The top of the ISO 19650 requirements pyramid. OIR describes the information an entire organization needs to make strategic and operational decisions across its whole property portfolio - not just one building. Think of it as the "why" behind everything else: the OIR shapes the AIR (what a specific asset needs), which shapes the EIR (what a specific project needs).
Most individual project teams never touch the OIR directly - it lives at the client organization's portfolio-management level - but it is worth knowing it exists, because it explains why some information requirements on a project can feel disconnected from that project's own scope.
OmniClass Construction Classification System
A North American classification standard that organizes construction data into numbered tables covering everything from building types to materials, work results, and disciplines. OmniClass is built from 15 numbered tables (Table 21 for Elements, Table 23 for Products, Table 33 for Disciplines, and so on), each usable independently or combined to classify a single object from multiple angles at once. It's the classification system most often paired with MasterFormat and referenced inside Revit family templates and keynote files for North American projects.
openBIM / closedBIM
Open formats vs vendor lock-in. Two approaches to sharing information. openBIM relies on open, vendor-neutral formats - IFC, BCF, IDS - so every party can work in the software they choose and the information is never locked to one vendor. closedBIM assumes everyone works in the same ecosystem ("everyone on Revit"), which simplifies day-to-day coordination but creates vendor lock-in and complicates long-term handover.
Public projects increasingly require openBIM deliverables.
A 360-degree photo capture platform that auto-maps site walkthroughs onto the floor plan for progress tracking. OpenSpace is a 360-degree photo capture platform - a worker walks the site wearing a camera, and the software automatically stitches and pins the footage to the floor plan, no manual tagging required. It's a more automated evolution of the same demand Progress Photography serves, aimed at capturing site conditions comprehensively rather than a handful of chosen shots.
A plan preparing the people and systems that will run a building - not just the building itself - to be ready by the day it opens. Common on hospitals and major infrastructure, it covers staff training, moving-in logistics, and system testing under real operating conditions - the practical extension of soft landings past the construction finish line.
A dynamic thermal simulation checking whether a space stays within acceptable temperature limits during a hot summer, not just whether it can be heated in winter. Well-insulated, airtight buildings built to hit energy targets can overheat badly in summer if solar gain and ventilation weren't checked alongside heating demand - an overheating assessment runs a full year of weather data against the model to catch that before it becomes a real occupant complaint. Shading, glazing ratio, and the ventilation strategy are usually the first things adjusted when an assessment flags a risk.
A Revit-generated table listing every circuit connected to a specific electrical panel, its load, and its breaker rating. It updates automatically as electrical circuits are added or changed - an electrician on site relies on it being accurate far more than on the plan view itself.
Designing geometry as a set of rules and relationships (parameters) rather than fixed shapes, so changing one value automatically updates everything connected to it. A parametrically designed staircase defined by "total rise divided by riser height" recalculates its step count the moment the floor-to-floor height changes. Grasshopper and Dynamo exist to push this idea further than a single family's own parameters can.
Elements defined by parameters - one change updates everything. The term that explains why Revit is not "AutoCAD in 3D". In parametric modeling every element is defined by parameters - dimensions, materials, rules and relationships - rather than frozen lines. Change one parameter and the element updates along with everything that depends on it: move a wall and the doors, dimensions and quantities follow.
This is what makes a BIM model smart rather than just drawn: geometry and data stay linked, and the model keeps itself consistent through every change.
The Revit category for parking space and aisle families used in site and civil layouts. Parking is a Revit category for parking space and drive-aisle families, used to lay out and count parking on a site plan - the count feeds directly into compliance checks against a project's required parking ratio.
A collaborative procurement approach where a client and contractor commit to working together across multiple projects, building trust and efficiency over time rather than re-tendering every job from scratch. It's a lighter-weight relative of a full framework agreement - less formal, but built on the same logic that repeat collaboration beats one-off competitive tendering for certain kinds of ongoing work.
A legal agreement between neighboring property owners in the UK covering work on or near a shared wall or boundary. It has to be in place before certain excavation or wall work starts - skipping it is a common, entirely avoidable source of neighbor disputes and delayed starts on site.
PAS 128: Specification for Underground Utility Detection, Verification and Location
A British specification classifying how reliably underground utilities (pipes, cables) have been surveyed and located, from desktop research up to verified physical exposure. PAS 128 defines quality levels (D through A, A being the most certain) for utility survey data, so a model showing an existing gas main can carry an explicit confidence rating - critical before excavation or foundation work begins near services nobody has physically verified.
Publicly Available Specification 1192
The UK's pre-ISO 19650 suite of BIM information-management standards. The PAS 1192 series (published by BSI, the British Standards Institution) was the UK's national suite of specifications for managing BIM information before ISO 19650 existed. PAS 1192-2 covered the capital delivery phase, PAS 1192-3 covered operational asset management, and PAS 1192-5 covered security-minded BIM.
ISO 19650 was built directly on top of PAS 1192 - the CDE zones (WIP, Shared, Published, Archive), the EIR/BEP pairing, and much of the terminology carried over almost unchanged. If you read an older UK BIM specification or contract, it likely still references PAS 1192 by name.
Retrofitting dwellings for improved energy efficiency — Specification and guidance
The UK standard governing how domestic retrofit projects must be assessed, designed, and installed. PAS 2035 sets out the process a domestic Retrofit project must follow - a whole-house assessment first, a coordinated design across all the measures being installed, and monitoring after completion - to avoid the unintended consequences (damp, poor ventilation) that piecemeal retrofit work has caused in the past. It's now a requirement for government-funded retrofit schemes in the UK.
Carbon Management in Buildings and Infrastructure
The UK standard for managing and reducing whole-life carbon across infrastructure and building projects. PAS 2080 sets out a framework for managing carbon across a project's whole value chain - client, designer, and contractor all sharing responsibility for measuring and reducing it - rather than leaving carbon reduction to any single party. It's become a common client requirement on UK infrastructure and increasingly building projects, sitting alongside the existing Embodied Carbon and Whole Life Carbon metrics as the process standard for actually managing them down.
Passivhaus (Passive House) Standard
A rigorous, performance-based energy-efficiency building standard focused on ultra-low heating/cooling demand through airtightness, insulation, and heat recovery - rather than points-based credits. Unlike LEED or BREEAM, which award credits across many categories, Passivhaus certifies a building against a small set of hard, measurable performance thresholds - primarily heating/cooling demand and airtightness (measured via a blower-door test). Because the standard is so sensitive to construction detailing, Passivhaus projects typically demand tighter coordination between the Revit model and the actual as-built envelope than a typical green-building certification.
A formal document certifying the value of work completed to date, which authorizes an interim payment to the contractor. The percentage complete stated on a payment certificate is increasingly checked against real quantities pulled from the model itself (via QTO or a tool like Assemble) rather than a contractor's own estimate, making an accurate, up-to-date model a direct input into the project's cash flow.
Portable Document Format
The universal, view-only document format used to publish drawing sets for review, markup, and distribution outside the model. Revit exports sheets to PDF directly, and background export lets that run without blocking further work in the model. Once exported, a PDF carries no live model data - it's a static snapshot for markup tools like Bluebeam, plan review, or simply sending to someone who has no access to the authoring model at all.
A financial guarantee, usually from a bank or insurer, that compensates the client if a contractor fails to complete the contracted work. A performance bond protects the client against outright contractor failure or insolvency, which is a different risk than Retention (protecting against defects in otherwise-completed work) or Liquidated Damages (compensating for lateness) - all three mechanisms often exist on the same contract, each covering a different failure mode.
A formal authorization required before starting a specific high-risk task, confirming precautions are in place. A Permit to Work is a formal authorization, signed off by a supervisor, required before starting a specific high-risk task - hot work, confined-space entry, working at height - confirming the necessary precautions are already in place. It's a control on the activity itself, distinct from the RAMS document that plans it.
The view setting controlling which elements from which construction phase are shown, hidden, or shown with an override, based on a view's assigned phase. Phasing sets which phase an element belongs to; the phase filter is what actually decides how a specific view chooses to display existing, demolished, and new work relative to that assignment.
Modeling what exists, what's demolished, and what's new across time. Revit's system for modeling a building across time rather than as one static snapshot. Every element gets assigned a Phase Created and, if relevant, a Phase Demolished, and every view is set to show a specific phase (or a phase comparison, like "New Construction" showing new work highlighted against a greyed-out existing building). This is essential for renovation and retrofit projects: the same model can represent existing conditions, demolition, and new work simultaneously, with each view filtering to show only what is relevant.
Phase Filters control exactly how each phase state gets drawn - what line style demolished elements get, whether existing elements show at all - giving full control over how the story of the building's timeline gets told on paper.
A reality-capture technique that reconstructs accurate 3D geometry and a point cloud from a large set of overlapping photographs, rather than a laser scanner. Software matches common points across dozens or hundreds of overlapping photos (often taken from a drone) to triangulate real-world coordinates - cheaper and faster to capture than laser scanning for large sites, though typically less precise for tight interior detail, which is why the two methods are often combined on the same project.
Project Information Model
The information model built during design and construction. One half of ISO 19650's central pair. The PIM is the information model built up during design and construction: models, drawings, specifications, schedules, and documentation, all developed and approved through the CDE.
At handover, the relevant parts of the PIM are transferred to the owner and become the basis of the AIM.
A Revit MEP system family that routes fluids - water, drainage, gas - between plumbing fixtures and mechanical equipment. Like ducts, pipes connect through connectors and auto-generate fittings as a run is drawn, but also carry a pipe system type (domestic hot water, sanitary, storm) that governs slope requirements and connection rules. Sanitary and storm systems typically need a minimum slope, which Revit can flag automatically if a run falls outside it.
Project Information Requirements
What the client needs to know to make decisions during a specific project. The third member of the OIR/AIR/PIR family. PIR captures the information a client needs during the life of one specific project - not to operate the finished asset (that's the AIR) and not for the whole organization (that's the OIR), but to make good decisions about this particular job: budget tracking, risk management, design approvals.
In practice, the EIR that a project team receives is usually assembled from a mix of the relevant AIR and PIR content - the client's way of saying "here is everything I need from you, for this project and for running the building afterward".
An early construction field-management app for plan markup and issue tracking, now folded into Autodesk Build. PlanGrid was one of the earliest construction field-management apps for markup and issue tracking on drawings from a tablet, acquired by Autodesk in 2018 and gradually folded into what's now Autodesk Build - still referenced often enough on older projects that it's worth knowing the name.
The formal submission to a local authority requesting permission to carry out a proposed development, including drawings, reports, and supporting statements. Biodiversity net gain assessments and a design and access statement are two of the supporting documents a planning application increasingly needs alongside the drawings themselves.
A construction defect and quality-management platform for tagging issues directly on drawings or BIM models. PlanRadar is a defect and quality-management platform widely used across European construction sites, letting teams pin issues directly onto drawings, floor plans, or a linked BIM model and track them through to resolution.
The Revit category for trees, shrubs, and other landscape vegetation families. Planting is a dedicated Revit category for landscape vegetation - trees, shrubs, groundcover - modeled as families that can carry data like species and mature height, distinct from the generic Site category used for grading and hardscape.
A Revit family category for sinks, toilets, and other fittings that connect to a building's water supply and drainage pipe systems. Plumbing fixtures carry connectors for supply and waste that pipe runs attach to, and their placement typically drives fixture unit counts used to size the drainage and supply systems feeding them. They're usually hosted to a wall or floor, and coordinated closely with casework in bathroom and kitchen layouts.
Laser-scan data used to model existing buildings. The bridge between existing buildings and BIM. A point cloud is the output of a 3D laser scan (or photogrammetry): millions of measured points that together form a precise digital snapshot of a physical space.
Scan to BIM is the workflow of importing that point cloud (in Revit: RCP/RCS files, linked like any other reference) and modeling the real building over it - walls, floors, structure, systems - to produce an accurate as-built model for renovation, retrofit, or documentation projects.
Post-Occupancy Evaluation (POE)
Systematically reviewing how a building actually performs and is used after occupants move in, and feeding those lessons back into future design and facilities decisions. A POE compares the "As Designed" intent against the "As Occupied" reality - actual energy use versus the performance simulation's prediction, occupant comfort surveys, how spaces get used differently than planned - closing the loop that Soft Landings and BS 8536 are both designed to set up from the start.
Discussions held after tenders are submitted to clarify, adjust, or agree final terms before a contract is awarded. It's the step between bid management and actually signing a contract - the point where an ambiguous line item in a bill of quantities usually gets resolved.
The UK contractual milestone where the works are complete enough for the client to take possession, minor defects aside. Practical Completion is the UK contractual milestone where the works are complete enough for the client to take possession and start using the building, even though minor defects remain - it's the trigger that starts the Defects Liability Period and releases the first portion of Retention. It's the UK-contract equivalent of the US term Substantial Completion.
The formal contractual document confirming a building is complete enough for the client to take possession and start using it, even if minor snags remain outstanding. Issuing this certificate is what actually starts the clock on the Defects Liability Period and hands operational responsibility to the client - the model and documentation package delivered around this milestone is what the facilities-management team will live with for years afterward.
Informal guidance sought from a planning authority before submitting a formal planning application. Pre-Application Advice is informal guidance a design team requests from a local planning authority before submitting a formal Planning Application - flagging likely objections or required reports early enough to address them in the scheme rather than after a costly formal submission gets refused.
The information a client is legally required to give the principal contractor before construction starts under the CDM Regulations - existing site hazards, known asbestos, ground conditions. It's the client's half of the CDM information exchange, feeding directly into the contractor's own construction phase plan.
Using sensor data and a digital twin to forecast when building equipment will need servicing, instead of following a fixed maintenance schedule or waiting for failure. A digital twin connected to live equipment sensors can flag a failing pump or an HVAC unit trending toward breakdown weeks in advance, letting facilities teams schedule the fix on their own terms rather than responding to an emergency - the practical payoff of investing in accurate BIM data for the operations phase.
A defined allowance in a contract sum for work by a named supplier or specialist not yet selected in detail. A Prime Cost Sum (PC Sum) covers work or supply from a specific named nominated subcontractor or supplier - a particular lift manufacturer, a specialist facade subcontractor - whose exact cost isn't finalized when the main contract is signed, adjusted once that supplier's own quote is confirmed. It's distinct from a Provisional Sum, which covers genuinely undefined scope rather than a known supplier with a pending price.
The CDM 2015 dutyholder responsible for managing health and safety on site during the construction phase. The Principal Contractor is the statutory CDM Regulations counterpart to the Principal Designer, taking over responsibility for planning, managing, and monitoring health and safety once construction starts - running the Site Induction, coordinating multiple trades' Permit to Work systems, and maintaining the Construction Phase Plan.
The CDM 2015 dutyholder responsible for managing health and safety risk during the pre-construction design phase. The Principal Designer is a statutory role under the UK's CDM Regulations, responsible for planning, managing, and monitoring health and safety during the pre-construction design phase - coordinating how designers eliminate or reduce risk before it ever reaches site. It's a legal duty distinct from being the lead architect or BIM Manager, though on smaller projects the same person sometimes holds more than one of those roles.
A widely used construction project management platform covering budgets, daily logs, RFIs, submittals, and drawing management for the construction phase. Where BIM 360/ACC and Autodesk Forma grew directly out of the design/model-coordination side of Autodesk's ecosystem, Procore is a construction-management-first platform - many general contractors run Procore for site operations while still coordinating the model itself through a separate BIM tool.
The overall strategy chosen for how a project's design and construction responsibilities are structured and contracted - the umbrella choice design-bid-build, design-and-build, and IPD all sit under. It's decided before almost anything else on a project, because it determines who's actually responsible for design risk once construction starts - a decision every other document on this list is written to reflect.
Professional Indemnity Insurance (PI)
Insurance covering a designer or consultant against claims arising from a mistake, omission, or negligent advice in their professional work. It's the standard risk transfer mechanism behind almost every design consultant's appointment - a client will usually require proof of current PI cover before signing anyone on.
Tracking real, on-site construction progress against the planned schedule (often the 4D model) using reality-capture data like drone photos or point clouds. A drone or 360-camera pass captures the site on a regular cadence, and that reality-capture data is compared against the 4D schedule model to flag what's ahead, on track, or falling behind - turning "how's it going out there" into an objective, model-based answer instead of a subjective site-visit impression.
Systematically photographing a construction site over time to document progress and support progress monitoring, valuations, and dispute records. It's the simplest, oldest form of reality capture on a project - still valuable even after photogrammetry and point clouds became standard, because a dated photo is sometimes the fastest way to prove what existed on a given day.
Project Bank Account (PBA)
A ring-fenced bank account that pays the main contractor and subcontractors directly and simultaneously, protecting subcontractors if the main contractor becomes insolvent. It's increasingly required on UK public sector projects specifically to fix a well-known failure mode - a subcontractor doing good work but never getting paid because the money stalled somewhere above them in the chain.
The tree-view panel listing every view, sheet, family, and group in a Revit project - the primary way most users navigate a model. The Project Browser organizes a project's views, sheets, schedules, families, groups, and links into an expandable tree, grouped by discipline and phase by default. Renaming, deleting, or opening almost anything in a project happens through it, which is why a well-organized browser (see Browser Organization) matters so much on large projects.
The integrated discipline of managing a project's cost, schedule, and risk together, rather than tracking each one separately in isolation. Earned value management and the critical path method are two of its core techniques - project controls is the discipline that puts them to use together rather than as standalone tools.
The overall document setting out how a project will be organized, managed, and delivered - broader than a BEP, which covers only the BIM-specific side of that plan. Where a BEP answers "how will information be managed," the project execution plan answers the wider question of how the whole project - budget, schedule, roles, risk - will actually be run.
Custom parameters added to specific categories within a single Revit project - visible in schedules and tags in that file, but not shared with other projects like Shared Parameters are. Project Parameters are the simplest of Revit's three parameter types to set up - useful for a one-off tracking field on this project only - but because they're baked into that single file, they can't be tagged, scheduled across other projects, or exported to ODBC the way a Shared Parameter can.
The extra costs a contractor incurs - site overheads, extended equipment hire, longer supervision - because a project ran longer than planned due to a delay that wasn't their fault. An extension of time gives a contractor more days; prolongation costs are the separate, and often more contested, claim for what those extra days actually cost to keep the site running.
The panel showing instance parameters for whatever is currently selected, or the active view's own settings when nothing is selected. With an element selected, the Properties Palette shows and lets you edit its instance parameters directly - the type selector at the top switches which family type is assigned. With nothing selected, it shows the current view's own properties instead, like its View Range, Detail Level, or applied View Template.
A Revit site element marking the legal boundary of a plot, used to check setbacks and site coverage. A Property Line marks the legal boundary of a site in Revit, either sketched directly or entered from surveyed distances and bearings, and can carry area/tax-parcel data. Once modeled, it's what lets a design be checked against required setbacks and site-coverage limits without leaving the model.
A placeholder allowance in a contract sum for work that can't be fully defined or priced at tender stage. A Provisional Sum is a placeholder amount included in a contract to cover work that can't be fully designed or priced when the contract is signed - existing-ground conditions, a client-selected fitting not yet chosen - and is adjusted to the actual cost once the work is properly defined, distinct from a Prime Cost Sum, which covers a specific named supplier's cost.
The American English term for a snagging list - the itemized list of defects to fix before a project is considered finished. It's the same practice as snagging under a different name - useful to know both terms, since which one a project uses often just depends on whether it follows UK or US contract conventions.
The Revit command that removes unused families, types, and styles from a project. A built-in Revit command that finds and removes elements loaded into a project but not actually placed anywhere - unused family types, line styles, materials, view templates - which quietly bloat file size and slow down performance over the life of a project without adding any value.
Purge Unused is one of the simplest, lowest-risk habits for keeping a model healthy: run it periodically (especially before a big milestone or handover), and a project that has picked up hundreds of unused, half-experimented-with elements over months of work gets noticeably lighter and faster with essentially no downside.
A free, open-source extension that lets Revit users write automation scripts in Python, an alternative to Dynamo's visual node-based scripting. Where Dynamo's visual graphs are approachable for modelers without a coding background, pyRevit appeals to users who already know or want to learn Python - the two aren't mutually exclusive, and some studios use Dynamo for quick one-off graphs and pyRevit for maintaining a shared library of reusable custom tools across a whole office.
A free, open-source GIS application, the most widely used alternative to Esri's commercial ArcGIS. It reads and writes the same open geospatial formats (like KML and LandXML) as its commercial competitors, making it a common low-cost entry point into GIS-BIM integration.
Quantity Takeoff
Extracting quantities directly from the model. The practical side of 5D. QTO means extracting quantities directly from the model - wall areas, duct lengths, concrete volumes, door counts - instead of measuring drawings by hand. In Revit this happens through Schedules; tools like Navisworks or Power BI let you slice quantities by level, zone or construction stage.
QTO quality depends directly on modeling quality: an element modeled wrong gets counted wrong.
The proactive processes that prevent defects, distinct from Quality Control's inspection of finished work. Quality Assurance (QA) is the set of processes built into a workflow to prevent defects before they happen - checklists, approval gates, standardized methods - as distinct from Quality Control (QC), which inspects work already done to catch defects that slipped through. A project's Quality Plan document typically sets out both.
The document setting out how a project or organization will check that its work meets the required standard, usually aligned with ISO 9001. It defines who checks what, how often, and against which standard - inspection and test plans, model quality checks, and sign-off procedures all sit underneath it. On a BIM project this usually includes explicit model quality review steps alongside the traditional physical inspections.
The discipline of measuring and costing construction work, from early estimates through final accounts. Quantity surveyors extract measured quantities from drawings or a BIM model - historically by hand, increasingly via QTO tools reading model data directly - to produce cost estimates, bills of quantities, and valuations as a project progresses. BIM's structured, parametric data makes this measurement faster and far less error-prone than working from 2D drawings alone.
A Revit family category for guardrails and handrails, hosted to a sketched path, a stair, or a ramp. Railings automatically follow the stair or ramp they're hosted to, updating baluster spacing and handrail geometry as the underlying run changes, or can be sketched freely along their own path for a balcony or mezzanine edge. Baluster placement patterns are rule-based, so a fixed spacing or a pattern tied to tread count stays consistent even as the railing's length changes.
A Revit system family, sketched like a stair run, that connects two levels with a sloped surface instead of steps. A ramp is sketched by drawing its run and landings between two levels, with slope calculated automatically the same way a stair's risers are, making it the standard way to model accessible routes. Railings host to a ramp exactly as they do to a stair.
Risk Assessment and Method Statement
A combined document assessing the risks of a specific task and the method for carrying it out safely. RAMS pairs a Risk Assessment (what could go wrong, how likely, how severe) with a Method Statement (the step-by-step safe way to carry out the task) into one document, produced before higher-risk site activities begin. It's the standard site-level companion to the project-wide Risk Register - one covers the whole project, RAMS covers a single task.
The umbrella term for scanning, drones, and photos used to record existing conditions. The umbrella term for every technique used to record the real, physical condition of a site or building digitally: laser scanning that produces a point cloud, drone photography, 360-degree photo documentation, and photogrammetry (building 3D geometry from overlapping photographs instead of a laser). Scan to BIM is the specific workflow of turning reality capture data into a usable Revit model - reality capture is the broader category that workflow belongs to.
On a renovation project, good reality capture at the start is what makes an accurate as built model possible later; skipping it usually means a model built on guesswork and old, unreliable drawings instead.
Reinforcing Bar
Steel bars embedded in concrete to carry tensile loads concrete alone can't resist - modeled in Revit as individual bars or bar sets hosted to a structural element. Rebar in Revit is hosted to a concrete element (a wall, slab, or column) and follows its geometry, so a change to the host's shape automatically adjusts the reinforcement laid inside it. A single bar or a shape-driven set can be placed at once, with cover, spacing, and hook geometry all controlled parametrically instead of drawn line by line.
Autodesk ReCap
Autodesk's reality-capture software, which processes raw laser-scan or photogrammetry data into a clean, lightweight point cloud that can be linked directly into a Revit project. Raw scanner output is usually far too heavy and noisy to work with directly, so ReCap indexes, cleans, and compresses it into its own .rcp/.rcs format before a modeler links it into Revit as an underlay for tracing walls, floors, and existing conditions at real-world scale - the practical first step in most Scan-to-BIM workflows.
The formal drawing deliverable capturing exactly what was built, issued as part of handover - the drawing-set equivalent of an as-built model. Where "as-built" describes a category of information generally, record drawings are the specific 2D document set a client actually receives at handover - and increasingly, that set is generated directly from the as-built model rather than redrawn from scratch.
2D construction lines used inside Revit's sketch modes to align, constrain, or set up geometry - distinct from a Work Plane, which is the 3D surface a sketch is drawn on. Reference planes are the invisible-in-3D guide lines a modeler adds inside a family editor or sketch (often locked with dimensions or parameters) to keep geometry aligned as it flexes - they're a sketch-time tool, while a Work Plane is the actual 3D surface hosting the whole sketch.
Inspecting site progress or quality via video call, drone footage, or 360-degree photos instead of an in-person site visit. It became mainstream almost overnight during the pandemic, and stuck around afterward simply because it's faster for routine checks - a drone survey feeding straight into it for anything at height or hard to reach.
Designing and managing a built asset to withstand and recover from climate-related and other disruptive events - flooding, extreme heat, power loss - over its working life. It's increasingly modeled alongside embodied and whole-life carbon rather than treated separately - a building designed for net-zero operation still needs a resilience plan for the climate conditions it will actually face over a 60-year life, not just the ones on file today.
Responsibility Matrix (RACI)
A table mapping who is Responsible, Accountable, Consulted, and Informed for each modeling or information task on a project. In an ISO 19650 workflow, a responsibility matrix is what actually assigns each piece of model content and information deliverable to a specific team or role, so a coordination clash or missed deliverable has a clear, agreed-upon owner rather than an ambiguous "someone should fix this."
A percentage of each payment withheld from a contractor until the works (or the Defects Liability Period) are satisfactorily complete, as financial leverage to ensure defects actually get fixed. A typical retention is 5% of each payment, with half released at Practical Completion and the rest at the end of the Defects Liability Period - a real financial incentive tied directly to how quickly and completely a contractor closes out the snag list.
A bond a contractor can provide instead of having cash Retention withheld from payments, freeing up their cash flow while still giving the client financial security. Instead of the client physically holding back 5% of every payment, the contractor's bank or insurer issues a bond covering the same risk - the contractor keeps full cash flow through the project, and the client can still call on the bond if defects go unfixed at the end of the Defects Liability Period.
Upgrading an existing building's performance - typically energy efficiency, systems, or safety - rather than designing and building something new. Retrofit projects almost always start with Scan-to-BIM (there's rarely an accurate existing model), and success is measured against Whole Life Costing and carbon targets rather than a fresh design brief - a fundamentally different modeling problem than new-build work, working around and constrained by what's already there.
A Revit tool that cuts a recessed horizontal groove into a wall or floor, the inverse of a Wall Sweep. A Reveal cuts a horizontal recessed groove into a wall or floor along a sketched path - the geometric inverse of a Wall Sweep, which adds material rather than removing it - commonly used for a shadow gap or a decorative recess between finishes.
Managing the flow of materials backward through the supply chain - from a deconstructed building back to a factory or a new project - for reuse or recycling. Ordinary supply chain management moves materials from factory to site; reverse logistics is the same discipline running the other way, and it's usually the harder direction to make economically viable.
A cloud-shaped annotation drawn around a part of a drawing that changed, visually flagging exactly what to look at in a re-issued sheet. It's the visual half of a two-part system - the cloud shows where a change happened on the sheet, while the revision schedule records what the change was, when, and why.
The table on a Revit sheet listing every revision issued for that drawing - a number, a date, and a description for each one. It's usually placed right next to the title block, giving anyone reading a printed drawing an instant history of every change without needing to compare it against an older version.
Autodesk's parametric BIM authoring software - the core modeling tool most of the industry's building information modeling actually happens in, across architecture, structure, and MEP. Revit was originally developed by Charles River Software and acquired by Autodesk in 2002 - its name is short for "Revise Instantly," a nod to its core idea: every wall, door, and schedule is a live view of one shared model, so a single change updates everywhere else automatically. That is the parametric, database-backed approach the rest of this glossary keeps referring back to - families, worksets, schedules, and the Revit API all exist inside Revit specifically, not as generic BIM concepts. Three separate disciplines (architecture, structure, MEP) work inside the same core product, usually coordinating through linked models and worksharing rather than separate software.
Revit Application Programming Interface
The programming interface that lets developers write custom add-ins and scripts to automate, extend, or control Revit directly. Anything Revit can do manually, the API can usually do programmatically - bulk-editing parameters, generating custom reports, automating repetitive modeling tasks, or building entire custom tools. Dynamo and most third-party Revit plugins are themselves built on top of the Revit API; power users write directly against it in C# or Python (via pyRevit) when they need something beyond what visual scripting offers.
A lower-cost, single-user version of Revit with a reduced feature set - no worksharing, no add-in/API support, and a simplified rendering engine. Revit LT covers the core modeling and documentation workflow at a fraction of full Revit's price, which makes it attractive to sole practitioners and small firms - but the missing worksharing and API support mean it can't participate in a multi-user central model or run Dynamo scripts, so growing firms typically outgrow it.
Autodesk's on-premise server for worksharing across multiple office locations. Autodesk's own solution for extending worksharing across multiple physical office locations without everyone connecting to the same local network. Instead of a single central model sitting on one office's server, Revit Server hosts the central model and lets each office's local Revit Server instance keep a synchronized copy, so a team in one city and a team in another can work on the same project through their own local, fast connection.
It has been increasingly overtaken by cloud worksharing (Autodesk Construction Cloud), which does the same job without dedicated server hardware in every office, but Revit Server is still common in larger firms with an existing IT infrastructure investment.
A real-time coordination and issue-tracking platform combining model review with BCF workflows. A coordination platform that combines federated model viewing, clash detection, and issue tracking into one real-time environment, aimed at making coordination meetings genuinely interactive - multiple people can navigate the same live 3D view together during a call, rather than one person sharing their screen while everyone else watches.
It competes directly with Navisworks and Solibri in the same coordination space, and like BIMcollab, leans on BCF to keep issues portable between different teams' software.
Revit Family
The file extension for a Revit family - a reusable, parametric component loaded into a project. An .rfa file is a single loadable family - a door, a light fixture, a piece of furniture - built and edited in the Family Editor, independent of any specific project. It gets loaded into a project the way an image gets inserted into a document, and the same .rfa can be reused across many different projects.
Request for Information
A formal question raised by one project party to another, usually the contractor asking the design team to clarify or resolve a gap in the drawings or model. RFIs are the standard mechanism for resolving ambiguity during construction - when something on site doesn't match the documents, or two disciplines' information conflicts, an RFI captures the question, routes it to whoever can answer, and creates a written record of the resolution. Frequent RFIs on a project are often a sign of coordination problems that better BIM clash detection could have caught earlier.
Revit Family Template
The file extension for a Revit family template - the starting point used to create a new family, not a finished family itself. An .rft file pre-wires the reference planes, category, and hosting behavior a new family needs before any real geometry is added - picking "Door.rft" versus "Generic Model face-based.rft" sets up completely different starting behavior. Family templates ship with Revit and are what a modeler opens via New > Family, not something loaded into a project directly.
Rhinoceros 3D
A free-form 3D modeling application, most often paired with Revit through Grasshopper, used for complex geometry that Revit's own modeling tools handle poorly. A double-curved facade panel or an organic canopy shape is often designed and rationalized in Rhino using Grasshopper's parametric tools, then brought into Revit as an imported form or adaptive component family for documentation and coordination with the rest of the building model.
The UK's staged framework for organizing a project from brief to use. A widely used UK framework (from the Royal Institute of British Architects) that divides a project into numbered stages - from 0 (Strategic Definition) through 7 (Use) - each with defined outputs and decision points. It is not a BIM standard on its own, but BIM specifications constantly reference it: an EIR will typically say what LOD is expected "by the end of Stage 3" or "by Stage 4," anchoring model detail to a stage everyone in the industry recognizes.
Other countries use their own equivalent staged frameworks, but the RIBA Plan of Work is the one referenced often enough internationally that it is worth knowing even outside the UK.
Royal Institution of Chartered Surveyors
The global professional body for chartered surveyors, including quantity surveyors, setting standards for measurement, valuation, and professional conduct across the property and construction industry. NRM, the New Rules of Measurement quantity surveyors work to daily, is itself an RICS publication - membership and its professional standards sit behind much of how quantity surveying and valuation are practiced in the UK and internationally.
Identifying, tracking, and mitigating project risks - coordination clashes, missing information, safety hazards - in a structured, prioritized way rather than reacting to problems as they surface. In a BIM context this usually takes the form of a live risk register cross-referenced against model elements and a responsibility matrix, so a genuinely serious coordination clash gets escalated ahead of a cosmetic one instead of both landing in the same undifferentiated issue list.
A live, maintained list of the risks identified on a project, each one scored, assigned an owner, and tracked with a mitigation plan. A design-stage risk register might flag an unresolved geotechnical uncertainty; a construction-stage one tracks a live weather delay. It's reviewed at every stage gate, and closing out an entry usually means either the risk was designed out or a mitigation genuinely worked - not that it was quietly forgotten.
Shifting responsibility for a specific risk from one party to another, usually through a contract clause or an insurance policy. A guaranteed maximum price is a form of risk transfer onto the contractor; professional indemnity insurance is a form of risk transfer onto an insurer - the same underlying idea applied to different parties.
Autodesk Robot Structural Analysis Professional
Autodesk's structural analysis software, which exchanges data bidirectionally with Revit so structural engineers can analyze loads and forces on the same model the architectural team is building. A structural engineer exports the analytical model (see Structural Analytical Model) from Revit into Robot, runs load cases and code checks there, then pushes reinforcement or member-size results back - keeping the physical Revit model and the engineering analysis in sync instead of maintained as two disconnected files.
A Revit system family, created by footprint, extrusion, or face, that forms a building's uppermost weatherproofing layer and can carry a pitch. The most common method - Roof by Footprint - sketches a boundary and applies a slope to selected edges, while Roof by Extrusion sweeps a profile along a path for more complex forms. Like walls and floors, a roof's layers (structure, insulation, waterproofing) live in its type, and it can host dormers, skylights, and other roof-based families.
A property controlling whether an element (a wall, a column, even a line) counts as a boundary when Revit calculates room and area geometry. A room that calculates the wrong area or refuses to fill with a color scheme almost always has a room-bounding mismatch nearby - a furniture family incorrectly set to room-bounding, or a partition wall incorrectly set to not room-bounding - making this one of the first properties to check when Room vs. Space calculations look wrong.
A per-room deliverable document that lists a space's required finishes, fittings, environmental targets, and equipment - often generated directly from BIM model data. Common on healthcare, education, and hospitality projects with hundreds of similar-but-distinct rooms, a Room Data Sheet is typically generated straight from Revit room parameters and schedules rather than authored by hand - keeping it automatically in sync whenever a room's finishes or area change in the model.
Revit's two competing element types for bounding an enclosed area - one architectural, one MEP. A frequent point of confusion for anyone coordinating architecture with MEP in Revit: Rooms and Spaces are two separate element types that can occupy the exact same physical volume but belong to different disciplines and different Revit categories entirely. Architects place and schedule Rooms; MEP engineers place Spaces (used for HVAC load calculations and energy analysis) - and the two do not automatically stay in sync with each other.
Best practice is usually to let Spaces derive their boundaries directly from the architectural model's Rooms wherever possible, and to re-check that link whenever the architectural layout changes - otherwise an MEP team can end up doing load calculations against room boundaries that no longer match the actual design.
Investigating a defect, delay, or incident to find its actual underlying cause, rather than just fixing the visible symptom. A cracked wall can be patched in an afternoon; root cause analysis is what tells you whether it'll just crack again because of a settlement issue nobody actually looked into.
Revit Project File (.rvt)
Revit's native project file format, carrying the full model and all its data. The native file extension of a Revit project - .rvt - which carries the complete model: geometry, parameters, views, sheets, and every loaded family, all in one proprietary binary file. Unlike exchange formats like IFC or DWG, an RVT file is not meant for cross-software exchange - it is Revit talking to Revit, preserving 100% of the model's native intelligence, which is exactly why it is the file format used for the central model in worksharing.
RVT files can grow large and, without regular maintenance (purging unused elements, auditing), gradually accumulate bloat that slows the whole team down - which is why file-health habits matter as much as modeling skill on a long-running project.
A digital construction platform for planning and tracking progress against process-based checklists on site. Sablono is a digital construction-management platform for planning work as repeatable process templates - a sequence of checklist steps per unit or room type - and tracking real-time progress against them on site, aimed at the highly repetitive scopes common in residential and hotel construction.
Standard Assessment Procedure
The UK government's official methodology for calculating a new dwelling's energy performance and carbon emissions, used to demonstrate regulatory compliance. Every new dwelling in England and Wales needs a SAP calculation before building control will sign it off, producing the figures behind its Energy Performance Certificate rating. Geometry, U-values, and system efficiencies feeding a SAP assessment increasingly come straight out of the Revit model rather than being re-entered by hand into separate energy software.
A QA process comparing an as-built point cloud scan against the design model to verify how accurately construction actually matches what was designed. Where Scan-to-BIM creates a model FROM a scan (usually for existing buildings with no model), Scan vs. BIM compares a NEW scan of freshly built work against an ALREADY-EXISTING design model - flagging deviations before they become expensive problems, a quality-control step increasingly run at key construction milestones rather than only at final handover.
The process of converting laser-scan point cloud data of an existing building into an intelligent BIM model. Surveyors capture an existing site or building with a laser scanner or photogrammetry to produce a point cloud, then modelers use that point cloud as an accurate reference to build walls, floors, and other elements in Revit (or another BIM tool) at real-world dimensions. It's the standard way to get reliable as-built models for renovation, retrofit, and facilities-management projects where no accurate existing model exists.
Revit Schedule
A live, tabular report of model data that updates automatically as the model changes. A table view in Revit that lists model elements and their parameters as rows and columns - a door schedule, a room finish schedule, a window schedule - built directly from live model data rather than typed in by hand. Because a Schedule is really just another view of the model, editing a value in the schedule changes the actual element, and editing the element updates the schedule instantly; the two are never out of sync the way a model and a separately-maintained spreadsheet always eventually are.
Schedules are also the most common practical output of QTO: a material takeoff schedule with a calculated quantity column is often the fastest way to get numbers out of a model and onto a cost plan.
A Revit tool that defines a reusable set of parameter values (like finish types) as named "keys," so a schedule can look up a whole group of values by picking one key name. Instead of typing "wall finish: paint, floor finish: tile, ceiling finish: acoustic panel" into every single room, a modeler assigns one key (say, "Finish Type 2") and the schedule key table fills in all three values automatically - built specifically to make a Room Data Sheet-style schedule fast to populate and consistent across hundreds of rooms.
A Revit tool that defines a 3D boundary controlling which grids and levels are visible in a given view, used to manage large or multi-building projects cleanly. On a large campus or multi-tower project, grids and levels would otherwise stretch across every view regardless of which building it belongs to; a scope box lets a modeler crop grid/level visibility to just the relevant building or zone in each view, without touching the extents of the actual grids and levels themselves.
A legal agreement attached to UK planning permission requiring a developer to fund or provide community benefits. A Section 106 Agreement is a legally binding obligation attached to a UK planning permission, requiring the developer to fund or deliver something in exchange for approval - affordable housing, a new school place contribution, highway improvements - negotiated between the council and developer alongside the planning application itself.
An interactive 3D clipping box in Revit that cuts away part of the model in a 3D view, letting a user look inside a building rather than only at its exterior. It's a live, view-specific tool for exploring a model interactively - unlike a crop region, which limits what a 2D view shows, or a scope box, which limits what datum elements appear across several views at once.
A Revit view type showing a vertical (or horizontal) cut through the model, revealing construction that a plan or elevation alone can't show. A section is drawn as a line and arrow through a plan or another view, and Revit generates a live view of everything the cutting plane passes through - wall layers, floor build-ups, structural connections - updating automatically as the model changes. Building sections cut through the whole structure; wall sections zoom into one specific construction detail at a much larger scale.
An approach to managing sensitive project information (per PAS 1192-5) so building data can't be exploited for physical, cyber, or personnel security threats. Not every building's information can be freely shared - airports, government facilities, and critical infrastructure need controls on who can access what, at what resolution, and through which systems. Security-minded BIM builds a security triage process into the standard ISO 19650 workflow, assessing sensitivity before information gets published rather than after.
A saved group of specific model elements in Revit that can be reselected instantly by name, without a Group's shared-geometry behavior or a Filter's rule-based logic. A modeler manually picks an odd, one-off combination of elements - say, every window on a single irregular elevation - saves it as a named selection set, and can reselect that exact same combination weeks later in one click, which neither a rule-based View Filter nor a geometry-sharing Group is built for.
One real-world anchor for all models. The number-one reason models "don't sit" on each other in coordination. Every Revit model has a Project Base Point (internal reference) and a Survey Point (anchor to the surveyor's coordinate system). Shared coordinates are the agreement of all disciplines on the same real-world anchor - so when the structural model is linked into the architectural one, they meet in the right place, at the right elevation, at the right rotation.
Setting them correctly on day one of the project saves weeks of pain.
The plain text file storing shared parameter definitions, which multiple families and projects can all reference to stay consistent. A firm typically maintains one central shared parameter file that every project and family template points to - split it across several inconsistent files, and the same parameter can end up with two different internal IDs in different projects.
One consistent data field across families and schedules. Revit's way of letting one piece of data exist consistently across families, projects and schedules. A shared parameter is defined once in an external .txt file with a unique GUID, and every family or project using it refers to the exact same field - which is why it can appear in schedules, tags and IFC exports.
Without shared parameters, "FireRating" in one family and "Fire_Rating" in another are two strangers that will never meet in the same schedule.
A Revit mechanism for coordinating the real-world position of linked models via a common site location, as an alternative to publishing shared coordinates directly. It's a less commonly used path to the same destination shared coordinates reach - useful when several models need to agree on a real-world position but publishing coordinates directly between them isn't practical.
A cloud worksharing feature letting a specific Revit view be shared with a stakeholder for review, without giving them full access to the model itself. It solves a specific access problem - a client or reviewer who has no Revit license and shouldn't see the whole working model can still open one shared view in a browser to leave comments.
A Revit schedule listing every sheet in a project's drawing set, typically used to generate the cover sheet's index. Since it's a live schedule, adding or removing a sheet updates the drawing index automatically - no more manually retyping a table of contents every time the sheet count changes.
Fabrication-level drawings produced by a subcontractor or manufacturer, derived from the BIM model. Detailed, fabrication-ready drawings produced by a subcontractor, fabricator, or manufacturer - showing exactly how a component will be built or installed, at a level of precision the design team's own drawings do not attempt. In a BIM workflow, shop drawings are increasingly generated directly from the model rather than redrawn from scratch, once the model reaches LOD 400.
Shop drawings usually require formal approval from the design team before fabrication starts, which is exactly the kind of milestone tracked through a project's issue tracking and review workflow - an unapproved shop drawing that gets fabricated anyway is a common, expensive mistake on a poorly coordinated project.
The rule that all project information must pass through the CDE at one controlled entry point, rather than being shared directly between parties by email or private folders. It sounds like a technicality, but it's what makes a CDE actually work: if a drawing can also be emailed directly to a subcontractor, there are now two versions in circulation and no way to know which one is current. A single point of entry is what keeps the CDE the genuine single source of truth instead of just one more copy of the files.
A procurement principle where one party is accountable for both design and construction, so a client has only one contract to enforce if something goes wrong. It's the underlying logic behind design-and-build's appeal - instead of a client managing a design team and a contractor separately, and arguing about whose fault a problem is, there's only one door to knock on.
The principle that one authoritative version of information exists, not scattered copies. The foundational principle behind most of BIM's process discipline: information about a project should exist in exactly one authoritative place, with everything else - drawings, schedules, reports - generated from it, rather than maintained as separate, parallel copies that inevitably drift out of sync. A schedule pulled live from the model is a single source of truth in action; a spreadsheet someone maintains by hand alongside the model is the opposite.
The CDE is the organizational mechanism that makes a single source of truth possible at the project level - a defined, agreed place where the current, correct version of every piece of information lives, so nobody is ever working from an outdated copy without realizing it.
Setting up a construction site at the very start of a project - welfare facilities, hoarding, security, temporary power - before any actual building work begins. It's the physical execution of the site logistics plan - the plan on paper becoming hoarding, cabins, and a compound gate in the real world.
The mandatory safety and orientation briefing every worker completes before first entering a construction site. Site Induction is the mandatory safety and orientation briefing every worker, visitor, or delivery driver completes before first setting foot on a construction site - covering hazards, emergency procedures, and site-specific rules. It's often the first place a digital site-diary or permit-to-work system records someone's presence.
The document mapping out crane positions, material storage, site access, and welfare facilities for a specific construction site. On a tight urban site it's often the single most argued-over document on the job - it's also exactly the kind of plan a digital rehearsal is used to test before committing to it on paper.
Modeling the temporary elements of a construction site itself - cranes, material laydown areas, site access routes - to plan a safe, efficient sequence of work. A site logistics model sits alongside the permanent building model and changes as construction progresses - a crane's reach and a material laydown zone that make sense in month two might need to move entirely by month eight, and planning that sequence in the model catches clashes a static 2D site plan would miss.
Precise measurement of a physical site, forming the ground-truth base for a model. A precise physical survey of a site - boundaries, existing levels, utilities, existing structures - carried out by a licensed surveyor and used as the accurate ground-truth base a model is built on top of. A site survey is typically imported as a linked drawing or point file and tied to the project's shared coordinates, anchoring everything modeled afterward to the real world.
Skipping or rushing a proper site survey is one of the most common sources of expensive downstream problems: a building modeled against inaccurate site data can end up with the wrong finished floor level, misaligned property boundaries, or a design that does not actually fit the real topography once construction starts.
A plan setting targets and methods for reducing, reusing, and recycling construction waste on a specific project. It tracks waste by type and destination - what gets recycled, what's reused on site, what actually ends up in landfill - and is increasingly tied to a project's circular economy and embodied carbon targets rather than treated as a standalone compliance document.
A sustainability rating for fit-out projects, covering scopes LEED and BREEAM don't reach at that scale. SKA Rating is a sustainability benchmark specifically for fit-out projects - assessing things like materials, waste, and energy at the Cat A/Cat B scope rather than a whole building - filling a gap the building-level BREEAM and LEED schemes weren't designed to cover.
A free-form 3D modeling application known for its ease of use, popular for early massing studies and concept design before a project moves into Revit. Many architecture students and small firms start a concept in SketchUp because its learning curve is far gentler than Revit's parametric approach - the tradeoff is that a SketchUp model carries no real building data (no wall types, no schedules), so it typically gets rebuilt as proper Revit families once the design is set, rather than imported wholesale.
SketchUp's native file format, storing its 3D model geometry, components, and scenes. It's the format behind the free 3D Warehouse library many SketchUp users pull furniture and site-context models from - useful for early massing and concept work, though it carries none of the parametric, data-rich structure a Revit family does.
The process of identifying, listing, and tracking defects or unfinished work ("snags") on a construction site, typically ahead of handover. A "snag list" (also called a punch list) is walked and photographed on site, then increasingly logged directly against BIM model elements using mobile apps or BCF issue files, so each defect is tied to the exact object, location, and responsible party rather than a loose spreadsheet row.
The actual, itemized list of defects found during snagging - each entry tracked until it's fixed and signed off. Clearing every item on the snagging list is what a certificate of making good defects formally confirms happened.
BSRIA Soft Landings
A structured handover process that keeps the design team involved after occupation. A framework (originally from BSRIA in the UK) for closing the gap between how a building was designed to perform and how it actually performs once people move in. Soft Landings keeps the design and construction team involved for a period after handover - typically a year or more - to fine-tune systems, answer the operator's questions, and compare real performance data against the original design intent.
It pairs naturally with BIM: the AIM and COBie data produced during the project become the baseline the Soft Landings team measures against, and lessons learned feed back into the next project's EIR.
Solibri Model Checker
A rules-based BIM model-checking and coordination tool built around open IFC. A model-checking and coordination platform (now owned by Nemetschek) built specifically around openBIM and IFC, rather than any single authoring tool. Solibri's strength is rule-based checking: instead of just visually spotting clashes, it can automatically verify a model against a defined rule set - fire-escape distances, accessibility clearances, missing information, LOD compliance - and flag every violation in a structured report.
It is a common alternative or companion to Navisworks, especially on projects that lean heavily on openBIM workflows and want checking that goes beyond geometric clashes into actual information quality.
Making sure every discipline's model elements occupy compatible space within the same federated model - the general principle clash detection actually checks for. Clash detection is the automated check; spatial coordination is the broader discipline it serves, including things a clash test alone won't catch, like leaving enough clearance around a valve for a technician to actually reach it.
The written document defining the quality, performance, and installation standards for materials and systems - the counterpart to the drawings' "what" and "where.". If drawings show what goes where, the specification says how good it has to be - which standard a material must meet, how it should be installed, and how it's tested or certified. On BIM projects, specification sections (often organized via MasterFormat or a national equivalent like NRM) are increasingly linked directly to model elements rather than living in a completely separate document.
An open-source data platform for AEC that streams and versions BIM data between different software (Revit, Rhino, Grasshopper, Blender) without exporting static files each time. Instead of exporting an IFC or Navisworks file and re-importing it whenever something changes, Speckle keeps live, versioned "streams" of model data that different tools can push to and pull from - closer to how a code repository works than a traditional file exchange. It's gained traction as a lighter, more automatable alternative to file-based interoperability, especially for teams already scripting with Dynamo or Grasshopper.
A Revit tool that divides a single element - a wall, a beam, a pipe - into two independent pieces at a chosen point. It's useful the moment two halves of what was one continuous wall need different properties - a different fire rating past a certain point, say - without redrawing anything from scratch.
A Revit annotation marking the exact height of a single point on the model - a floor level, a site grade point, a roof low point. Site and roof drainage plans depend heavily on it - a series of spot elevations across a sloped surface is how a reviewer confirms water will actually flow toward a drain rather than pool somewhere unintended.
A Revit wall type made of two or more separately-typed walls stacked vertically into one composite element. A Stacked Wall combines two or more differently-typed walls vertically into a single element - a masonry base with a curtain-wall upper section, for instance - so they move and edit together as one wall while each sub-wall keeps its own compound structure.
A project governance structure in which work only moves to the next stage after passing a formal review "gate" - checking that the previous stage's deliverables and decisions are complete and approved. The RIBA Plan of Work's numbered stages are a well-known example - each stage gate exists to stop a project sliding into detailed design before the client has actually approved the concept it's based on.
A Revit system family, typically built "by component," that connects two levels with a run of treads and risers calculated from the height between them. A stair-by-component run automatically calculates riser height and tread depth from the level-to-level height and a target riser count, updating live as either level moves. Landings, winders, and supports are separate sub-components of the same run, and railings host directly to it.
Revit's flexible stair-creation tool that builds stairs from separate parts (run, landing, support) instead of a single sketched profile. It replaced the older sketch-based stair tool as the default for a reason - each component stays independently editable, which handles awkward real-world stair geometry far more gracefully.
Identifying everyone with an interest in a project's outcome and actively managing their expectations and involvement throughout its life. A responsibility matrix tells you who does what; stakeholder management is the broader, ongoing job of keeping everyone who cares about the outcome informed and aligned, whether or not they're formally assigned a task.
A formal declaration that completed work or a product meets the relevant specification or standard. A Statement of Compliance is a formal declaration - from a contractor, manufacturer, or specialist subcontractor - confirming that completed work or a supplied product meets the relevant Specification or standard. It's a lighter-weight assurance document than a full test certificate, often requested for straightforward items where independent testing isn't practical.
A utility company with a legal right to install and maintain infrastructure - water, gas, electricity, telecoms - on or near a site. A Statutory Undertaker is a utility company - water, gas, electricity, telecoms - with a legal right to install and maintain its apparatus on or near a site, independent of the landowner's permission. Coordinating with them, via a Utility Search early on and often a Wayleave later, is a fixed part of any project that touches existing infrastructure.
Standard for the Exchange of Product Model Data
A neutral 3D geometry exchange format from the manufacturing world, used at the boundary between BIM and product/component fabrication. When a Revit-modeled component needs to actually get manufactured - a custom curtain wall bracket or a piece of structural steel - STEP is often the format that hands its precise geometry off to CNC machines and manufacturing CAD software, since it was built for mechanical engineering precision rather than architectural documentation.
Stereolithography
A simple mesh file format used almost universally for 3D printing. STL is a simple triangulated-mesh format with no material, color, or metadata - just surface geometry - used almost universally as the input for 3D printers. Models exported from Revit or Rhino for a physical study model or a 3D-printed mockup typically go through STL.
A cloud BIM viewer used by site and facilities teams to check tasks, defects, and checklists against the model. StreamBIM is a cloud-based BIM viewing and checklist platform aimed at the site and facilities-management side rather than design authoring - workers use it to view the model, tick off checklists, and log issues against specific model elements without needing an authoring license.
The simplified line-and-node model structural engineers use to run calculations. A simplified representation of the structure - beams and columns reduced to centerlines, walls reduced to planes - that structural analysis software actually calculates against, running alongside the full Physical Model (the real geometry everyone else sees and coordinates with) inside the same Revit structural elements.
The two models can drift apart if not managed carefully: moving a column's physical geometry does not always automatically move its analytical line the same way, and a structural engineer's calculations are only as trustworthy as how well the analytical model actually matches the real, physical design intent.
The formal engineering document showing the load calculations and design checks behind a structure, proving it meets the required codes. A finite element analysis or a structural optimization pass usually feeds directly into it - the calculations document is the formal, checkable record of what that analysis actually concluded.
A vertical load-bearing Revit family category - steel, concrete, or timber - hosted to a level and typically aligned to a grid intersection. Structural columns snap to grid intersections by default, carry a structural material and cross-section, and participate in the analytical model the same way beams and framing do. They're a distinct family category from architectural columns, which exist purely for visual/decorative purposes and carry no structural load path.
Revit's tool for modeling the physical steel connections (bolts, plates, welds) between structural members. Structural Connections is Revit's toolset for modeling the actual steel connection between two structural members - bolts, end plates, welds - rather than just the members meeting at a point. It matters most for steel-detailing handoff, where a connection's real geometry affects fabrication and clash checks that a simplified beam-to-column join can't catch.
Revit's category for the elements that transfer a building's loads into the ground - isolated footings, wall footings, and structural slabs. Foundation families come in three flavors: isolated footings sit under individual columns, wall footings run continuously beneath a bearing wall, and structural slabs cover a broader area - a raft or mat foundation being the most common example. All three carry structural material and bearing-capacity data that geotechnical and structural teams coordinate against.
Revit's category for horizontal and sloped structural members - beams, joists, braces - placed between columns or walls to carry the structure's loads. Structural framing elements host to two points (or a sketched path) rather than to a level the way a wall or floor does, and carry a structural material, cross-section, and analytical representation that feeds into load combinations and finite element analysis. Point-to-point steel modeling and split-with-gap tools both operate directly on this category.
Refining a structural design to use less material or cost while still meeting all the required load and safety criteria. It's finite element analysis put to a specific purpose - not just checking whether a design works, but iterating toward the leanest design that still works.
The American-contract milestone marking a project as essentially finished and usable, even with a punch list of minor items still outstanding - the US equivalent of practical completion. AIA contract documents define it precisely because so much else hangs on that date - warranty periods, retainage release, and the client's insurance obligations often all start counting from it.
The ISO 19650 status codes (S0-S7) marking exactly what a piece of information is fit for - coordination, review, or construction - as it moves through a CDE. A model or drawing marked S2 ("suitable for information") is very different from one marked A2 ("authorized for construction") - suitability codes make that distinction explicit and machine-readable instead of relying on a filename or an email saying so. They're what actually moves a piece of information between a CDE's WIP, Shared, and Published states.
Revit's built-in tool for visualizing the sun's position and shadows on a model at any date, time, and location, used for shading and daylight design checks. A quick sun-path study inside Revit itself can catch an obvious overshadowing problem or confirm a shading device works at the summer solstice, without needing to export to a dedicated building performance simulation tool for every early design question.
Coordinating and managing the network of subcontractors and suppliers that deliver materials and specialist work to a project. A digital fabrication supplier is only as reliable as the supply chain feeding it materials on time - which is why a delayed shipment three tiers down can still blow a critical path months later.
Choosing materials, suppliers, and contractors based partly on their environmental and social impact, not price and quality alone. It's the procurement-side counterpart to embodied carbon targets - a low-carbon design can still fail its sustainability goals if the materials behind it are sourced from whoever's cheapest regardless of their footprint.
Synchro Pro
Dedicated 4D construction scheduling software that links a project schedule directly to 3D model elements to simulate and manage the sequence of construction. Instead of a schedule and a model living as two disconnected documents, Synchro ties each schedule task to the specific elements it builds, so the whole team can visually watch the building "grow" over time and immediately spot sequencing conflicts a spreadsheet-based schedule alone would never reveal.
A Revit panel listing every MEP system in a project (each duct run, each piping loop) organized by system rather than by view or sheet. Where the project browser organizes a model by view, the system browser organizes it by system - the tool an MEP engineer reaches for to select every element on one specific duct run at once, wherever it appears.
A Revit family type built into the project itself - walls, floors, roofs, ceilings - that can't be loaded, saved, or shared as a separate file the way a loadable family can. It's the fundamental split every new Revit user has to learn: loadable families (like a door or a piece of furniture) live in RFA files and get loaded into a project, while system families are always project-hosted, copied between projects via transfer project standards instead of a family load.
A Revit interface feature allowing multiple open projects to sit in separate tabs within a single window, instead of each project opening its own full application instance. Copying an element between two open projects, or quickly comparing a detail across a current job and a past reference project, becomes a simple tab-switch instead of alt-tabbing between two entirely separate Revit windows - a workflow convenience most new users only appreciate once they've felt the friction of the old way.
View-specific annotation elements in Revit that automatically display a parameter value (like a door number or wall type) from the model element they're attached to. A tag isn't independent text - it's a live readout tied to a specific model element's parameter, so if that element's value changes (or the element gets deleted), the tag updates or disappears with it, which keeps drawing documentation from silently drifting out of sync with the model.
A lean-construction practice where cost and value targets are set collaboratively up front, and design decisions are made to meet them - the reverse of designing first and costing afterward. It puts the owner, designer, and contractor in the room together from the start, treating the target cost as a design constraint rather than an estimate produced after the design is already fixed - closer in spirit to integrated project delivery than to a traditional design-bid-build sequence.
The person who directs information production for a task team, following agreed standards and methods. Within a BIM task team (as set out in ISO 19650 and BS 1192), the Task Information Manager plans and directs the day-to-day production of information, ensures the team follows the project's naming conventions and standards, and reviews information before it is shared for coordination. Distinct from the wider Information Manager role, which operates at the whole-project level rather than within a single task team.
A discipline-specific team producing information under the Lead Appointed Party. A single-discipline team - the structural engineers, the MEP consultants, the facade specialists - appointed to produce a specific portion of the project's information, working under the coordination of the Lead Appointed Party. Each Task Team is responsible for its own TIDP, and for delivering its discipline model to the agreed LOD at each milestone.
In everyday language this is simply "one of the consultant teams on the project" - ISO 19650's contribution is giving that relationship a precise name and a defined place in the overall information-delivery structure, rather than leaving it implicit.
Trimble's BIM authoring tool specialized for structural engineering, particularly strong in steel and precast concrete detailing. Where Revit is a generalist across every discipline, Tekla goes deep on one - connection-level steel detail accurate enough to drive digital fabrication directly, which is why it's common to see a Tekla structural model federated with a Revit architectural one.
Template (.rte)
A starting file carrying the office standard. Every project's starting file - and the DNA of an office standard. A template (.rte in Revit) comes pre-loaded with view settings, view templates, families, line styles, sheets, parameters and naming conventions - so every new project starts organized and consistent.
An office with a good template produces uniform work fast; an office without one reinvents the wheel every project. Building an office template is one of the highest-return investments in BIM adoption.
The dimensions Revit automatically displays while placing or moving an element, showing its distance to nearby references - gone once the action is confirmed, unless converted to a permanent dimension. They're a placement aid, not documentation - a small permanent-dimension icon appears next to them precisely so a user can promote a useful temporary reading into a real dimension string before it disappears.
The engineering design of structures that support the works during construction but aren't part of the finished building - scaffolding, formwork, propping, shoring. It's a distinct engineering discipline from the permanent structural design, and a frequent source of on-site accidents when it's treated as an afterthought rather than designed and checked properly.
The full package of drawings, specifications, quantities, and conditions issued to contractors so they can submit a competitive bid for the work. Under Design-Bid-Build, the quality of the tender package directly determines how comparable and reliable the bids that come back actually are - an incomplete or ambiguous model/specification at tender stage is one of the most common sources of costly change orders once construction starts.
A Revit 2D annotation element for adding written notes to a view, distinct from 3D Model Text. A Text Note is Revit's basic 2D annotation element for adding written notes directly to a drawing - leader lines, formatting, and a family of text types are all built in. It's view-specific like a Detail Line, and distinct from Keynoting, which pulls its text from a linked parameter rather than being typed freely.
A localized point in a building's envelope - a balcony slab, a steel beam through insulation - where heat escapes much faster than through the surrounding construction. A thermal bridge undermines an otherwise well-insulated wall or roof assembly, showing up as a cold spot, a condensation risk, and a real gap between a design's calculated and actual energy performance. Detailing insulation continuity around structural penetrations - and modeling those junctions accurately in Revit - is what a thermal bridging assessment actually checks.
A contract clause allowing someone who wasn't an original party to the contract - a future building owner, for instance - to enforce its terms directly. It's a lighter-weight alternative to a collateral warranty, achieving a similar practical outcome with less separate paperwork for each new party who needs protection.
The bordered information panel on a Revit sheet holding the project name, drawing title, scale, date, and revision history. It's itself an annotation family, custom-built or edited per firm, and it's what every revision schedule and sheet list ultimately displays alongside.
A short, recurring on-site briefing covering a specific safety topic relevant to that day's work. A Toolbox Talk is a short, informal briefing - typically five to fifteen minutes - held on site covering one specific safety topic relevant to that day's work, such as working at height or a new piece of equipment. Unlike the one-time Site Induction, these repeat regularly throughout a project.
A Revit element type introduced to replace the older Toposurface tool, modeling terrain as a true solid with layers, materials, and sub-elements like a floor slab rather than just a surface. A Toposurface was purely geometric - a shape with no material layers or quantity data - while a Toposolid behaves like a proper building element: it can host sub-elements, split into layers (topsoil over subgrade), and feed schedules the way a floor or wall assembly does, closing a long-standing gap between site modeling and building modeling.
Revit's older, purely geometric site-terrain element - a shape with no material layers or quantity data, superseded for most new work by the Toposolid. A Toposurface models a site's ground shape from survey points, contour lines, or an imported point cloud, but carries no material layers or schedulable quantities the way a Toposolid does. It still appears in older projects and remains useful for simple site context, but Autodesk's newer Toposolid is now the recommended tool whenever the site itself needs to behave like a real building element.
A plan controlling how vehicles - deliveries, cranes, concrete trucks - move around and through a construction site and its surrounding roads. On a tight urban site it works hand in hand with the site logistics plan, but focuses specifically on the public road network rather than the site boundary itself.
A Revit tool that copies system families, view templates, line styles, and other project settings from one project file into another, without having to rebuild them by hand. Since system families and view templates can't be loaded like an RFA family, this is the actual mechanism firms use to keep standards consistent across projects - typically run once against a firm's master template file rather than project-to-project.
A formal record accompanying a set of documents or models sent from one party to another, listing what was sent, when, and why. A transmittal is the paper trail of information exchange - it names the sender, recipient, purpose (for information, for review, for construction), revision numbers, and a list of every file included, so both sides have a shared, auditable record of what was issued and when. On BIM projects it's usually generated automatically by the Common Data Environment when a set of documents changes CDE state.
A planning-application document assessing a development's traffic generation and access arrangements. A Transport Statement assesses the traffic and access implications of a proposed development - trip generation, parking provision, pedestrian and cycle routes - submitted alongside the planning application for schemes below the scale that triggers a full Transport Assessment. It directly informs how much Parking a site plan can or must provide.
A survey cataloguing existing trees on a site and assessing the impact a proposed development has on them. A Tree Survey catalogues every existing tree on and around a site - species, condition, retention category - and the resulting Arboricultural Impact Assessment sets out which trees a proposed development can retain and what root-protection measures construction near them needs. Like an Ecological Survey, it's often a planning-approval precondition and can constrain where a building or its access road can actually go.
A basic Revit editing tool that shortens or lengthens walls, lines, or beams so they meet cleanly at a corner or intersection. It's one of the very first tools a new Revit user learns - clicking two walls that don't quite meet and having them snap together cleanly instead of manually dragging endpoints.
Trimble's cloud collaboration platform, common on infrastructure and Tekla projects. Trimble's cloud-based collaboration platform - a CDE-style environment for sharing, viewing, and coordinating models across teams, particularly common on projects using Tekla Structures or other Trimble tools, and widely used in infrastructure and heavy-civil work alongside building projects.
It plays a similar functional role to Autodesk Construction Cloud, but from a different vendor ecosystem - which project you will meet it on usually comes down to which authoring software the structural or infrastructure discipline is using.
A Revit structural family built from a triangulated pattern of members, spanning long distances with less material than a solid beam. A Truss in Revit is a structural family built from a repeating triangulated pattern of chords and webs, used to span long distances - roofs, bridges - with far less material than a solid beam would need. Revit's truss tool lets you sketch a profile once and generates the internal member pattern automatically, and it stays parametric if the span changes.
Epic Games' real-time visualization tool, built on the Unreal Engine. A real-time architectural visualization tool from Epic Games (the makers of the Unreal Engine and Fortnite), offering the same "instant photorealistic walkthrough" value as Enscape, but built on genuine game-engine technology. Models come in from Revit and other BIM tools via Datasmith, Epic's dedicated import pipeline, preserving materials and hierarchy far better than a generic export would.
Twinmotion and Enscape occupy roughly the same niche and are frequently compared directly - the choice between them usually comes down to rendering style preference, VR support needs, and which one a firm's existing licenses already cover.
A procurement process where a contractor is appointed early based on preliminary information, then works with the design team to agree a final price before construction starts. It brings the contractor's buildability input into the design earlier than a traditional single-stage tender would - closer in spirit to early contractor involvement than to a pure design-bid-build split.
The two levels of data an element carries - shared by every copy, or unique to one. One of the first genuinely confusing ideas for anyone new to Revit. A Type parameter is shared by every placed instance of that type - change the fire rating on one door of "Door Single 900mm" and every door of that exact type updates, because it is really one shared definition. An Instance parameter belongs to one specific placed element only - its Mark number, its Level, its exact height above the floor - and changing it affects nothing else.
Getting this distinction right is the difference between a model where a single correction fixes forty doors at once, and one where you are manually fixing forty doors one by one.
A Revit text file that lists every type variant of a family, letting users load specific sizes or configurations without opening the whole family. Rather than loading an entire family with every possible size (say, a door family with forty width/height combinations) and picking one, a type catalog lets a user pick just the specific type they need straight from the Insert dialog - keeping projects lighter and family management cleaner, especially for manufacturer content with many variants.
Thermal Transmittance
A measure of how much heat passes through a building element per square meter per degree of temperature difference - lower means better insulated. A wall, roof, or window's U-value is calculated from the thermal properties and thickness of every layer in its compound structure, so getting it right in Revit depends directly on modeling real, correctly specified materials rather than generic placeholders. Energy codes and standards like Passivhaus set maximum U-values as hard performance targets that a design has to meet.
A faded, non-editable reference to another level shown behind the current view - typically the floor below, used to check alignment between levels. It's how a drafter checks that a wall on the second floor actually lines up with the wall supporting it below, without switching back and forth between two separate plan views.
Unified Classification for the Construction Industry
A UK-developed classification system that organizes construction information into consistent tables - by system, product, space, and more - so it can be tagged, filtered, and shared consistently across a project. Uniclass groups information under tables like Systems, Products, Spaces/Locations, and Entities, and each item gets a short alphanumeric code (e.g. Ss_25_10 for a wall system) that stays consistent whether it's referenced in a drawing, a schedule, or a COBie handover file. It's most common on UK and Commonwealth projects, and pairs naturally with classification fields already built into Revit's family and material parameters.
Uniformat Classification for Building Elements
A North American classification system organized by building elements and systems (foundations, superstructure, exterior enclosure) rather than by trade or work result. Where MasterFormat organizes information by trade (concrete, masonry, doors and windows), Uniformat groups the same building by what it physically is made of - substructure, shell, interiors, services - which makes it especially useful for early cost estimating and elemental quantity takeoffs, before trade-specific specifications even exist.
A real-time 3D engine used for interactive walkthroughs, VR, and gamified training built from BIM data. Unity is a real-time 3D engine, alongside Unreal Engine one of the two dominant choices for turning exported BIM geometry into an interactive walkthrough, VR experience, or gamified safety-training simulation - generally favored for lighter-weight or mobile-targeted builds where Unreal's heavier rendering pipeline isn't needed.
A real-time 3D game engine increasingly used directly for high-end architectural visualization and VR, the underlying technology Twinmotion itself is built on. Twinmotion trades some of Unreal's raw flexibility for a much faster, AEC-tailored workflow - a studio that needs full creative control over lighting, materials, and interactivity beyond what Twinmotion's simplified interface offers will often go straight to Unreal itself instead.
Universal Scene Description
An open 3D scene-description framework, originally built for film production, increasingly used to bring BIM models into real-time visualization and simulation pipelines like NVIDIA Omniverse. USD's ability to layer and merge huge scenes from multiple sources non-destructively is what makes it attractive for AEC beyond film - a Revit model can be converted to USD and combined with other data sources in a shared real-time environment without flattening everything into one fixed file the way older exchange formats do.
A search of existing underground utility records before design, revealing pipes and cables that constrain the site. A Utility Search requests records from every Statutory Undertaker with apparatus near a site - water, gas, electricity, telecoms - to find out what's buried underground before design starts, since an undocumented main or cable can force a foundation or drainage redesign if it's discovered only once digging begins.
A high-end rendering engine, available as a Revit plugin, known for photorealistic lighting and material accuracy rather than real-time speed. Unlike the real-time engines built for fast design-stage walkthroughs (Enscape, Twinmotion, Lumion), V-Ray renders take longer to compute in exchange for more physically accurate light bounces and materials - the tool of choice when the final image itself is the deliverable, like a competition board or a hero marketing shot.
A structured process for cutting cost without sacrificing required function or quality. A structured process for reviewing a design specifically to find ways to reduce cost while still meeting the project's required function and quality - substituting materials, simplifying a detail, questioning whether a specified system is actually necessary - as distinct from simply "cutting corners," which sacrifices quality to save money.
BIM makes value engineering far more informed: because a model carries live QTO and cost data, a proposed substitution's actual cost and quantity impact can be tested in the model directly, rather than estimated roughly on paper, and the impact of a change ripples visibly through every schedule and drawing that depends on it.
A structured, whole-project process for making sure every design and procurement decision delivers the best balance of cost, quality, and function - broader than a single value engineering exercise. Where value engineering is usually a targeted exercise applied to a specific design once it exists, value management runs throughout the project lifecycle, shaping the brief and decisions from the very start rather than optimizing after the fact.
A lean-construction technique for visually mapping every step in a process to spot waste, delay, and rework that don't add value for the client. It's a diagnostic tool lean construction borrows directly from manufacturing - drawing out the actual flow of a process is often the fastest way to see where it's genuinely breaking down.
Virtual Design & Construction
Using models to plan the construction itself. A term you will meet constantly in job postings and large construction companies. VDC is the management approach that wraps around BIM: using virtual models to plan the construction itself - coordination, schedules, site logistics and budget - before anyone reaches the field.
If BIM is the information and the model, VDC is how the project team uses them to make execution decisions. In practice, a "BIM coordinator" role at a contractor is very close to VDC work.
The overall approach a design takes to bringing fresh air into a building and removing stale air - natural, mechanical, or a mix of both. A natural ventilation strategy relies on openable windows and stack or cross-ventilation airflow; a mechanical strategy uses ducted supply and extract systems instead, trading energy use for tighter control over air quality and comfort. As buildings get built increasingly airtight to hit energy targets, the ventilation strategy becomes the counterbalance that keeps indoor air genuinely healthy to breathe.
Tracking and managing changes to a model or document over time, so previous versions can be recovered and it's always clear which version is current. A CDE's own status/revision fields are its version control mechanism at the project level; Revit's central-and-local file system is the same idea at the single-file level.
A Revit rule that overrides the graphic appearance (color, line style, visibility) of elements in a view based on their parameter values, without changing the model itself. Instead of manually recoloring every wall by hand, a view filter says "any wall where Fire Rating equals 2 Hours turns red in this view" - applied per view or view template, purely graphical, and completely reversible since it never touches the actual model data. Common uses include coding phases, disciplines, or fire ratings by color across a whole set of drawings at once.
The set of horizontal planes (top, cut, bottom, and view depth) that determine what a Revit plan view actually shows and at what height it slices through the model. A plan view showing a kitchen counter but not the upper cabinets above it, or missing a low beam that should appear as a dashed line, is almost always a View Range setting problem rather than a modeling error - one of the most common sources of confusion for anyone new to reading or producing Revit plan views.
A saved bundle of view settings applied in one click for consistent graphics. A saved collection of view settings - visibility and graphics overrides, scale, detail level, phase, view range, and more - that can be applied to a view in a single click, and optionally locked so nobody can accidentally change it. View Templates are how an office keeps every floor plan, section, and elevation looking consistent across a project (and across every project, if the templates live in the office Template), instead of every team member configuring visibility settings by hand.
They are one of the highest-leverage tools in a well-run Revit office: a good set of view templates turns "make this drawing look right" from a 20-minute manual task into a two-second dropdown selection.
The 3D navigation widget in the corner of a Revit view, letting you snap to standard orthographic views or drag to any custom orientation. Clicking a face, edge, or corner of the ViewCube snaps the view to a standard angle (top, front, isometric corner), while dragging it rotates freely - the same tool exists across most Autodesk products, not just Revit. A small house icon next to it resets the view to the model's default home orientation.
Visibility/Graphics Overrides (VG)
The per-view dialog controlling which categories, elements, and filters show or hide, and how they're drawn - distinct from a View Template, which bundles many such settings together. VG (opened with the shortcut VG or VV) is where a modeler tweaks a single view's line weights, hatch patterns, or category visibility on the fly - a View Template, by contrast, packages a whole set of VG and other view settings into one reusable, lockable preset applied across many views at once.
The agreed plan for how a large project's model is split into separate files/volumes (by zone, floor, or discipline) so worksharing and coordination stay manageable. On a large project, one single Revit file becomes too heavy for anyone to work in efficiently, so the team agrees up front on how to split it - often by tower, floor band, or zone - and documents where each split's boundaries sit so linked models stay aligned and no scope falls between two volumes unowned.
An animated camera path through a Revit model, letting a viewer experience moving through the building rather than looking at a single static view. It's a simpler, built-in alternative to exporting a model into Twinmotion or Lumion for a fully rendered flythrough - lower fidelity, but immediate, with no extra software involved.
A system family in Revit built from stacked layers (structure, insulation, finishes) that hosts doors, windows, and other openings. A wall's layers - each with its own material, thickness, and function (structure, thermal, finish) - are defined once in a type and reused across every instance of that type, so editing the type's layer stack updates every wall using it at once. Walls automatically join at corners and clean up intersections with other walls, and everything from doors to curtain panels hosts to them.
How Revit automatically resolves the geometry where two or more walls meet at a corner or intersection - which one's layers wrap around the other. It's one of the most common sources of confusing-looking corners in a plan - the automatic join usually gets it right, but disallowing or overriding it manually is a routine fix when it doesn't.
A horizontal decorative or functional profile added along a wall - a cornice, a skirting board, a belt course - hosted on the wall but modeled as its own element. It follows the wall's own path automatically, including around corners and openings, instead of being drawn as separate straight segments that would need manual updating every time the wall changes.
Revit's built-in alerts flagging modeling problems that don't stop work but should be fixed. The built-in alerts Revit raises when something in the model is geometrically or logically questionable - overlapping walls, elements at the wrong level, rooms that aren't fully enclosed - without actually blocking the user from continuing to work. A small number of warnings is normal on any active project; a model with thousands of accumulated, ignored Warnings is usually a sign of deeper, unaddressed coordination or quality problems.
Reviewing and triaging the warnings list periodically - fixing what is real, understanding and dismissing what is a false positive - is a standard part of the model-health checks a BIM Coordinator runs before a milestone or handover.
A manufacturer's or subcontractor's guarantee covering a specific product or system for a set period, separate from and often longer than the general Defects Liability Period. A roof membrane might carry a 20-year manufacturer warranty even though the general Defects Liability Period on the whole project ends after 12 months - tracking which specific product warranties apply to which model elements is exactly the kind of non-geometric data an Asset Information Model is built to carry into operation.
A legal agreement granting a utility company access across private land to install or maintain apparatus. A Wayleave is a legal agreement granting a Statutory Undertaker access across private land - often a temporary or revocable right rather than a permanent one - to install or maintain apparatus like an overhead cable or an underground pipe. It's distinct from an easement, which typically runs permanently with the land title itself.
A certification focused on how a building affects the health of the people inside it. Where LEED and BREEAM focus mainly on a building's environmental footprint, the WELL Building Standard certifies how the building affects the health and wellbeing of its occupants - air and water quality, lighting, acoustics, thermal comfort, and mental health considerations. It is increasingly requested alongside LEED or BREEAM rather than instead of them, especially for workplace and residential projects where occupant experience is a selling point.
As with the other certifications, the data a WELL assessment needs - daylight levels, ventilation rates, material transparency - overlaps heavily with information a properly developed BIM model can already provide.
A building's total carbon footprint across its entire lifecycle, embodied plus operational. The complete carbon picture of a building across its entire lifecycle: embodied carbon from materials and construction, operational carbon from decades of energy use, and end-of-life carbon from eventual demolition or deconstruction, all added together. Assessing whole life carbon requires exactly the kind of rich, structured data BIM is built to hold - quantities, material types, expected service life, energy performance - pulled together from a single model rather than assembled by hand from separate reports.
It is increasingly what regulations and certifications like LEED and BREEAM are moving toward requiring, replacing older assessments that only looked at operational energy in isolation.
Whole Life Costing (WLC)
Calculating a building's total cost - construction plus every future cost of operating, maintaining, and eventually replacing it - rather than just its upfront construction price. A cheaper HVAC system to build can easily cost more over 30 years of energy use and replacement parts than a pricier, more efficient one - Whole Life Costing is the discipline of comparing options on that full timeline instead of the upfront number, using the same quantities and system data already captured in the model.
A hosted Revit family category that cuts an opening in a wall for glazing, sized by type parameters like width, height, and sill height. Like a door, a window is hosted to a wall and cuts it automatically wherever placed, but adds a sill height parameter controlling how far above the floor the opening starts. Sash, frame, and glazing are all part of the family geometry, so swapping a window's type can change its look site-wide without re-placing every instance.
Work in Progress
Unfinished work not yet approved for sharing. The private zone inside the CDE where each discipline works on their own model before sharing it with the wider team. WIP information has not been checked or approved - it is the raw working file.
Promoting information out of WIP and into the Shared zone is a formal step: it means the information has been reviewed and is ready for the rest of the team to coordinate against.
Work Breakdown Structure (WBS)
Breaking a project down into a hierarchy of smaller, manageable pieces of work - the standard scaffolding a schedule and a budget are both built on. Uniformat and Omniclass are essentially standardized WBS structures for building elements - which is exactly why a well-built BIM model's own hierarchy so often lines up with the project's cost and schedule breakdown too.
The invisible reference surface Revit uses to sketch and place new geometry. The invisible flat reference surface Revit uses whenever you sketch or place something - by default it is tied to the current view or level, but it can be set explicitly to a face, a reference plane, or a specific grid to sketch somewhere other than flat and horizontal, like on a sloped roof or an angled wall.
Confusion about "why did that element go where I didn't expect" is very often a Work Plane problem in disguise - Revit placed the new geometry relative to whatever plane was active, not necessarily the one the user assumed. Understanding work planes explicitly is one of the fastest ways to stop fighting Revit's placement logic and start using it deliberately.
The logical divisions of a shared central model, split by team or building zone. The mechanism inside worksharing that splits one central model into logical, independently-editable chunks - shell and core, interiors, site, MEP - so multiple people can work on the same file at once without constantly stepping on each other. Every element belongs to exactly one workset, and each user can choose which worksets are open and visible in their own session, which is also how a large, heavy model stays workable: closing worksets you don't need speeds up your local session considerably.
Worksets are about dividing ownership within one file; if you need to bring in a genuinely separate file, that is what Linked Models are for.
Central Model & Worksets
A whole team working on one Revit model at once. The terms every junior hears in week one on a real project. Worksharing is Revit's mode for letting a whole team work on one model at the same time: the project lives in a Central Model (on a server or in the cloud), each person works on a synced local copy, and changes flow back with "Synchronize with Central". Worksets split the model into logical chunks - shell, interiors, site - so ownership and visibility can be managed per team. If you ever wondered why file names end with "_Central" - this is why.
A Revit view mode that color-codes elements by workset, owner, or edit status directly in the model view - a visual alternative to checking the separate Worksharing Monitor dialog. Instead of opening the Worksharing Monitor dialog to check who owns what, a modeler can toggle Worksharing Display directly in a 3D view or plan to see it painted across the actual geometry - useful for quickly spotting which parts of the model are actively being edited by teammates right now.
A Revit dialog showing the live status of a worksharing session - who's editing what, which worksets are open, and current sync activity across the team. When a save-to-central is running slowly or a team member can't get an editing request granted, the Worksharing Monitor is the first place to check - it shows exactly who's connected, what they're borrowing, and whether the central model itself is under heavy load at that moment.
An open-source .NET toolkit for reading, creating, and validating IFC data. xBIM is an open-source .NET toolkit for reading, writing, and validating IFC data programmatically - used by developers building custom BIM data checks, converters, or viewers on the .NET stack, the same niche BonsaiBIM and IfcOpenShell fill on the Python/Blender side.
A Revit MEP grouping of rooms or spaces sharing a common HVAC system, used for load and energy analysis. A Zone groups multiple rooms or spaces that share a common HVAC system or thermostat, used to roll up heating and cooling loads for equipment sizing and energy analysis rather than calculating every room in isolation - the MEP-side grouping concept sitting alongside the architectural Room vs. Space distinction.