Embodied Carbon
The total greenhouse gas emissions released in producing, transporting, and installing a building's materials, with concrete and steel the largest contributors on most projects, as distinct from a building's operational carbon, which comes from energy used to run it after construction is complete.
Why it matters
A building's operational energy use gets most of the sustainability attention because it's easier to measure and improve over time, but embodied carbon is locked in the moment materials are manufactured and installed; there's no opportunity to reduce it later the way a building's operational efficiency can be upgraded after the fact.
On a real project
A design team compares two structural systems with similar cost and performance and chooses the one using a lower-carbon concrete mix, since that choice is fixed once the structure is built, unlike the building's operational energy use, which later efficiency upgrades could still improve.
Who this matters most to
A Sustainability/LEED Consultant tracks embodied carbon as part of a project's overall sustainability strategy, often alongside operational energy targets. An Estimator increasingly fields material substitution requests driven by embodied carbon goals, weighing them against cost and availability the same way any other substitution gets evaluated.
Where this goes wrong
A project focuses its entire sustainability effort on the building's projected operational energy use, without ever accounting for the emissions locked in by its structural material choices. The project markets itself as low-carbon while its embodied carbon footprint, set irreversibly during construction, goes entirely unaddressed.