The California Carbon Report: Analysis of Embodied and Operational Carbon Impacts of 30 Buildings
Actors in the built environment are promoting strategies targeted at reducing the environmental impacts of buildings. Many government agencies, design companies, builders, and developers have proposed voluntary net-zero commitments to drive change across the sector. Similarly, policymakers at both the state and national levels have been passing successful legislation to achieve mandatory emissions reductions, and many of these policies rely heavily on building-related decarbonization. Though all of these commitments and policies vary in their scopes and ambition levels, they all ultimately seek to reduce GHG emissions in alignment with Paris Agreement targets. Still, building decarbonization at scale has continued to prove challenging.
In this study, we investigated the use of whole life carbon assessment (WLCA) through a sample of 30 new construction building projects located in the State of California that were sourced from design practitioners as part of the CLF WBLCA Benchmark Study (v2). California was chosen for this preliminary study owing to its unique climate, large population, geographic size, rapidly decarbonizing electrical grid, ambitious climate targets, and quickly evolving policy landscape. By conducting this analysis, we sought to answer the following questions:
- What is the projected balance of emissions between embodied and operational carbon over time for a sample of new buildings in California?
- What are reasonable estimates of embodied and operational carbon intensities for the buildings analyzed?
- What are the most significant contributors to embodied carbon impacts from different buildings’ scopes, elements, or materials?
- What are the current gaps and challenges within industry practices toward developing comprehensive whole life carbon assessments?
- How do the results vary based on changes to LCA methods and assumptions?