Embodied carbon's growing importance

The architectural community is becoming more focused on reducing the carbon emissions caused during the extraction, manufacture and transportation of products used in their buildings (embodied or “upfront” carbon). This topic is now receiving as much of their attention as reducing carbon emissions from buildings during their operational life (operational carbon).

According to Architecture 2030, embodied carbon will be responsible for almost half of the total new building construction emissions between now and 2050. Today, embodied carbon emissions from the building sector are responsible for 11% of annual global greenhouse gas emissions [1].

While strategies, can be implemented in a building over time to reduce operational carbon, the embodied carbon of a building has already been spent – emitted into the atmosphere, contributing to climate change – before the building is even occupied. Given that the equivalent of an entire New York City is predicted to be added to the planet every 34 days for the next 40 years [1, 2], this points to a clear priority of reducing embodied carbon.

The market is beginning to react. Recently, the Buy Clean California Act (also known as Assembly Bill 262) was enacted, requiring high energy intensive building products - glass, structural steel, carbon steel rebar and mineral wool board insulation – used in California’s publicly funded projects to meet a minimum global warming potential (GWP). GWP is expressed in carbon dioxide (CO2) equivalents and is a measure of embodied carbon.

Skanska, a global construction company and signatory of the Paris Climate Accord, has been leading the way in driving construction material sourcing based on embodied carbon in the U.S. The company recently launched a tool (the EC3 calculator) in collaboration with the Carbon Leadership Forum and Microsoft, which provides the industry with easy access to material carbon emissions data, allowing for comparisons. Skanska is actively using the tool to make sourcing decisions.

Stacey Smedley, regional director of sustainability for Skanska’s building operations, recently demonstrated the use of the tool at a Façade Tectonics Institute Forum event to compare fenestration products from two manufacturers who had published EPDs.