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.