California Embodied Carbon Law: How to Prepare for AB 2446

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California Embodied Carbon Law: How to Prepare for AB 2446

Some exciting news coming out of California means big things for greenhouse gas (GHG) emissions associated with the building sector. With 25% of the state’s emissions resulting from buildings, the passage of AB 2446 into law, which targets embodied carbon reduction of building materials, is a significant step towards addressing climate change. Embodied carbon refers to the GHG emissions caused by sourcing, manufacturing, transportation, installation, maintenance, and disposal of construction materials. This can be measured and monitored using life cycle assessments (LCAs). With California’s climate leadership only growing, this law paves the way for renewed focus on embodied or upfront carbon reduction across the building sector.

Here we give you the highlights of the law, how this may impact the development landscape in California, and what you can do to prepare for it.


On September 16th 2022, California’s governor signed AB 2446 (Carbon Intensity of Construction and Building Materials Act) into law, requiring all new non-residential buildings over 10,000 square feet and residential projects with at least 5 units to submit life cycle assessments and product-specific Environmental Product Declarations (EPDs) of building materials used. This sets the stage for widespread GHG emission reduction in the built environment. It also requires the California Air Resources Board (ARB) to establish a framework to monitor and reduce GHG emissions of building materials.

Key milestones for the state board include:

  • Completing embodied carbon framework by July 1st, 2025
  • Establishing emissions baseline for the construction industry in 2026
  • Reducing GHG emissions of building materials by 40% from baseline by 2035, with an interim target of 20% reduction by 2030

The law requires ARB to encourage the production and use of low-carbon construction materials by leveraging state and federal financial incentives where possible to drive market demand. This can significantly lower emissions associated with a product or project without increasing the cost to the owner. This is big news for low-carbon construction alternatives!

In a recent study by the Carbon Leadership Forum and C40 cities aimed at evaluating the potential of city policies to aid emission reduction targets, the authors identified that the most impactful measures include reducing building level embodied carbon, incentivizing adaptive reuse, and limiting emissions from concrete used in buildings. While there is still much work to be done, the results from this proof-of-concept study demonstrate that AB 2446 can be an effective first step in checking building sector-related emissions.


AB 2446 will have a large impact on developers and the development landscape in California. As a starting point, here’s what developers should consider.

Considerations for Developers

#1: Utilize existing resources and carbon reduction guidelines

Optimizing the quantity of building materials used, or using bio-based products through design decisions can significantly reduce embodied carbon emissions. The Carbon Smart Materials Palette provides guidelines for reducing emissions on commonly used building materials and introduces low carbon or bio-based alternatives. Once concept design is finalized, conducting a whole building LCA can help assess the overall upfront carbon and identify the most environmentally impactful areas. The LCA findings can guide general contractors in procuring products that have lower emissions compared to the industry average and those with product-specific or Type III EPDs. Some commonly used design-integrated LCA and material procurement tools include One Click LCA, tallyCAT, EC3, and Athena Impact Estimator, among others. Other available embodied carbon resources are listed in the AIA-CLF Embodied Carbon Toolkit.

#2: Identify synergies with other policies and green building certifications

The Buy Clean California Act (BCCA), LEED v4.1 Material Life Cycle Impact Reduction credit, and Living Building Challenge Material Embodied Carbon imperative, all target upfront carbon of building materials and reward carbon reduction. By understanding these synergies, developers can streamline their efforts to achieve multiple targets.

#3: Collaborate early with industry stakeholders

Improved collaboration between owners, designers, engineers, contractors, suppliers, and researchers develops a shared understanding of carbon reduction strategies.

Impact on Development Landscape in California

#1: Accelerate the adoption of alternate building systems and materials

AB 2446 is likely to accelerate the shift from conventional carbon intensive structural systems like concrete to low-carbon alternatives such as mass timber, recycled steel, and composite systems. It will also encourage innovation and the introduction of carbon sequestering products such as bamboo, hempcrete, or strawbale, as well as the systematic phase out of their carbon intensive counterparts.

#2: Increase adaptive reuse

Compared to new construction, adaptive reuse of existing buildings can save up to 75% of upfront carbon emissions. This law could catalyze an increase in renovation projects, and the site selection process is likely to consider more existing buildings that can be potentially restored.

#3: Expand available product-specific or Type III Environmental Product Declarations

Financial incentives and regulations encouraging the roll out of low-carbon materials and requirement of whole building LCAs will encourage more suppliers to publish product-specific EPDs and potentially reduce the cost of low impact products. This will also improve the data accuracy in LCAs.

Whether you’re ready for the new framework to go into effect or unsure where to start, we’d love to discuss your options for embodied carbon reduction. Reach out to connect with our carbon services experts.