Status: ACTIVE
Assembly Bill 1815 (Wicks)
What the bill does:
AB 1815, authored by Assembly member Buffy Wicks, co-sponsored by HAC and the California Housing Consortium, prohibits local jurisdictions from imposing or enforcing building standards that exceed the state minimum standards in the California Building Standards Code on factory-built housing projects. The bill targets building code fragmentation, a barrier that has kept factory-built housing from reaching scale in California even though it holds real promise for cutting construction costs and speeding up production timelines. Factory-built projects depend on standardized designs that can be replicated across markets to achieve efficiency, but varying local requirements currently make that standardization impossible.
By requiring all factory-built housing projects to be built to the state code, AB 1815 gives factories the regulatory certainty they need to scale up production statewide. The Terner Center has identified this kind of building code reform as a meaningful opportunity to make factory-built housing more viable, and HAC and CHC are backing the bill as a direct response to one of the clearest cost drivers in the state's housing shortage.
Why this bill matters:
Factory-built housing is one of the more promising tools for bringing down construction costs and shortening timelines, but it hasn't scaled in California because factories can't rely on a single set of standards. A modular unit designed to meet one city's amendments to the building code often can't be sold as-is in the next city over, even though both cities are subject to the same state minimum code. That forces manufacturers to either customize designs project by project, which erases the cost savings of factory production, or avoid certain markets altogether. AB 1815 matters because it removes that friction at the source: it stops local jurisdictions from layering their own building standards on top of the state code for factory-built projects, so a single design can actually be replicated statewide.
AB 1815 prohibits local jurisdictions from imposing or enforcing building standards on factory-built housing that exceed the state minimum standards in the California Building Standards Code. In practice, that means a factory can design to one standard and deploy that same design anywhere in California without re-engineering it to satisfy a patchwork of local amendments. The Terner Center's research on this exact fragmentation problem helped shape the case for the bill: standardized, replicable designs are what let factory-built housing achieve real production efficiencies, and that only works if the rules don't change from jurisdiction to jurisdiction.
Contact Ali Sapirman at Ali@housingactioncoalition.org for more information.
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