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.