AB 1815: Factory-built housing: building standards and local requirements.

Official summary

Legislative Counsel’s Digest (official, as of the latest version). Written by nonpartisan legislative staff; reproduced verbatim.

Existing law, the California Building Standards Law, establishes the California Building Standards Commission within the Government Operations Agency. Existing law requires the commission to approve and adopt building standards and to codify those standards in the California Building Standards Code.

Existing law, the California Factory-Built Housing Law, generally regulates the design, manufacture, and installation of factory-built housing, as defined and specified. That law specifically and entirely reserves to local jurisdictions certain local requirements, including local use zone requirements, snow load requirements, and wind pressure requirements. That law provides that any person who violates any of those provisions and other specified law is guilty of a misdemeanor, as specified.

This bill also would prohibit a city, county, city and county, or district from imposing or enforcing local building standards applicable to a factory-built housing structure, as defined, that exceed or differ from the applicable mandatory standards contained in the California Building Standards Code. The bill would authorize a city or county to make changes or modifications in the requirements contained in the provisions published in the California Building Standards Code that are reasonably necessary to maintain minimum health and safety because of local climatic, geological, or topographical conditions, subject to the city or county making a specified finding. The bill would create a rebuttable presumption in favor of a determination that facilitates the use of factory-built housing and allows a project to qualify as a factory-built housing structure.

This bill would define certain key terms for purposes of the California Factory-Built Housing Law. In this regard, the bill would define “building assembly” to mean assembled construction materials, components, subsystems, subassemblies or other systems designed for use in, or as part of, factory-built housing, and “factory-built housing structure” as a residential building where at least 23 of the new or converted square footage is designated for residential use and in which at least 30% of the residential use portion of the building is built using factory-built housing. The bill would recast the definition of “factory-built housing” to mean, among other things, a residential building, dwelling unit, building component, building assembly, or building system that is manufactured in a specified manner.

The bill would make other conforming changes to definitions in the California Factory-Built Housing Law, the Sales and Use Tax Law, and the Vehicle Code.

By adding to the duties of local officials, and expanding the scope of a crime, this bill would impose a state-mandated local program.

Sponsors

Sponsors by party (alphabetical): Democratic 5 · Republican 1

“Support” is shown only as formal sponsorship recorded by the legislature. Roll-call votes are available on the official bill page.

Recent official actions

1. September 29, 2026Chaptered by Secretary of State - Chapter 782, Statutes of 2026.
2. September 29, 2026Approved by the Governor.
3. September 10, 2026Enrolled and presented to the Governor at 3 p.m.
4. August 30, 2026Senate amendments concurred in. To Engrossing and Enrolling. (Ayes 74. Noes 0. Page 6868.).
5. August 28, 2026In Assembly. Concurrence in Senate amendments pending.
6. August 28, 2026Read third time. Passed. Ordered to the Assembly. (Ayes 40. Noes 0.).
7. August 24, 2026Read second time. Ordered to third reading.
8. August 21, 2026Read second time and amended. Ordered returned to second reading.
9. August 20, 2026Read third time and amended. Ordered to second reading.
10. August 13, 2026Read second time. Ordered to third reading.
11. August 13, 2026From committee: Do pass. (Ayes 7. Noes 0.) (August 13).
12. August 3, 2026In committee: Referred to APPR. suspense file.