California updates building code to reduce embodied carbon

The new changes will come into effect on 1 July 2024

The state of California has updated its building code in a bid to limit the amount of embodied carbon emissions allowed in commercial and school buildings. The California Building Standards Commission (CBSC) is said to have voted the changes to two building codes into effect; the move is said to make the state the first in the United States to implement embodied carbon reduction in certain buildings.
Embodied carbon covers carbon emissions generated from the entire lifespan of a building, including manufacturing, construction, maintenance and eventual demolition.
The new code will “limit embodied carbon emissions in the construction, remodel, or adaptive reuse of commercial buildings larger than 100,000sqft (9,230sqm) and school projects over 50,000sqft (4,650sqm),” according to The American Institute of Architects (AIA) California, which worked closely with policy-makers on the changes.
The new changes will come into effect 1 July 2024. The change is an amendment to the 2022 California Green Building Standards Code (CALGreen), California’s first statewide green building code, which was first developed to supplement the general code in 2007, said a report.
“This action is a real catalyst for change that will push the industry forward in rapidly addressing the growing climate emergency,” said William Leddy, AIA California Vice President of Climate Action.
In California, construction activity is said to contribute 40% of the state’s greenhouse gas pollution. By reducing embodied carbon, the state aims to mitigate its contribution to climate change and promote sustainable building practices.
The compliance options include reusing at least 45% of an existing structure, using materials that meet specific emission limits, and using a performance-based approach that involves analysing the entire lifecycle of a building, the report added.
“The most sustainable buildings are the ones that are already built. Prioritising the reuse of existing buildings not only accelerates the reduction of embodied carbon emissions from new construction, it ‘incentivises’ the industry to address California’s severe housing crisis more quickly and efficiently, creating more sustainable and resilient communities,” concluded Leddy.