What is Happening on AB 2446?

• By: admin
• On: 07/01/2025 12:08:39
• In: CalCIMA News

The legislation applies to all building materials–whether concrete, wood, metal, windows, asphalt, or insulation. It applies to new residential developments of 5 homes or more and new buildings over 10,000 square feet.

The legislation requires two things of concrete and other building materials manufacturers:

1. Submittal of Type III Environmental Product Declarations (EPD) or similar data
2. Report data to CARB, beginning in 2026, that products are meeting the carbon reduction targets

The first stage for CARB in implementing AB 2446 is to have 1) a framework, or methodology, to develop a baseline from which to measure the carbon intensity of building materials. The baseline has to be based on 2026 data or whatever is most recent. Additionally, it must have 2) a reporting mechanism to obtain data from product manufacturers.   

For the baseline development methodology, CARB is considering two alternatives.  

• The U.S. EPA's Environmentally-Extended Input Output (USEEIO) Models for materials. It collects and collates average emissions data for materials from a variety of data sources, or 
• A combination of industry average data from EPDs and life cycle assessment (LCA). For LCAs, they are considering whether to focus only on the manufacturing phase or all phases of a materials' use and life. 
• Each has advantages and disadvantages. The USEEIO models provide a broader look and consistency among the variety of building materials being considered, whereas EPDs and LCA provide more of a realistic picture of what is actually happening at plants in California.

For carbon reporting, CARB is also considering a couple of options: 

• One is to request EPDs, but ask for ones that are updated every 2 years (compared to the current 5 years), focus on specific emissions of interest, and that use CARB-approved emissions factors. 
• The other is simply to develop their own criteria for manufacturers to report energy use; material inputs, output, and quantities; and total facility carbon emissions. 

For materials' manufacturers, the methodology and reporting methods are the two big ticket items at this time. There are other things on CARB's list, including fees to administer the reporting,and how to assess cost impacts from lower carbon materials on home and building construction.  For this, they are considering whether to gather financial information from producers.  

So, to complete this first stage of the regulatory process, producers can expect in the coming months more workshops, reports, and regulatory proposals. The aim is to have the regulation done by the end of the year, and begin the reporting program in 2026.  

After this is completed, the next stage will be for CARB to develop by the end of 2028 the means to achieve the 40% emission reductions by 2035.