When looking at the carbon intensity of a building, heavy focus is placed on the operational emissions. We have a pretty good idea on how to reduce these through increasing the performance of the building envelope and systems to reduce energy use, then supplying that energy from renewable sources. However, the building materials themselves can impart a substantial carbon debt (embodied carbon) and it is equally important to include those in a carbon intensity analysis.
For example, typical concrete and steel have high embodied carbon and substantially contribute to that carbon debt. Or, we look to insulation to reduce operational emissions, but its embodied carbon can greatly diminish that benefit.
In a sense, there’s a carbon payback aspect to the design. We’ve been offered general guidance to reduce the use of high intensity materials, but there’s a simple tool allowing us to quantify those tradeoffs and better understand their impact.
Builders for Climate Action developed the Building Emissions Accounting for Materials (BEAM) Estimator to analyze those upfront emissions and guide designers toward lower impact buildings.