Bill Text: CA AB1815 | 2025-2026 | Regular Session | Amended
Bill Title: Factory-built housing: building standards and local requirements.
Sponsorship: Moderate Partisan Bill (Democrat 5-1)
Status: (Engrossed) 2026-07-02 - Read second time and amended. Re-referred to Com. on APPR. [AB1815 Detail]
Download: California-2025-AB1815-Amended.html
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Amended
IN
Senate
July 02, 2026 |
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Amended
IN
Senate
June 22, 2026 |
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Amended
IN
Assembly
April 27, 2026 |
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Amended
IN
Assembly
March 19, 2026 |
CALIFORNIA LEGISLATURE—
2025–2026 REGULAR SESSION
Assembly Bill
No. 1815
| Introduced by Assembly Members Wicks and Quirk-Silva (Coauthors: Assembly Members Caloza, Mark González, Harabedian, and Hoover) |
February 10, 2026 |
An act to amend Sections 19969.3, 19971, 19972, 19975.1, 19976.05, and 19993 of, and to add Sections 19970.1 and 19971.1 to, the Health and Safety Code, relating to housing.
LEGISLATIVE COUNSEL'S DIGEST
AB 1815, as amended, Wicks.
Factory-built housing: building standards and local requirements.
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 these provisions and other specified law is guilty of a misdemeanor, as specified.
This bill
would instead reserve to local jurisdictions local use zone requirements, local design standard requirements, local flood resistant control standards, and local wildfire safety building requirements, as provided. The bill would provide that the Legislature finds and declares that the California Building Standards Code addresses regional variations in snow load and wind pressure, as specified. The
This bill also would prohibit a city, county, or city and county from imposing or enforcing building standards that exceed the state minimum building standards in the California Building Standards Code on
a factory-built housing construction project. The The bill would clarify that this provision does not apply to structures of a development project that are not factory-built housing.
This bill would revise and recast definitions of key terms for purposes of the California Factory-Built Housing Law. In this regard, the bill would generally define “factory-built housing” to mean a residential building with a ratio of the cost of factory-built components to the total direct hard costs for the scope of construction work within the footprint of a structure that is at least 15%, as specified, where at
least 2/3 of the new or converted square footage is designated for residential use. By adding to the duties of local officials, and expanding the scope of a crime, this bill would impose a state-mandated local program.
The bill would include findings that changes proposed by this bill address a matter of statewide concern rather than a municipal affair and, therefore, apply to all cities, including charter cities.
The California Constitution requires the state to reimburse local agencies and school districts for certain costs mandated by the state. Statutory provisions establish procedures for making that reimbursement.
This bill would provide that no reimbursement is required by this act for specified reasons.
Digest Key
Vote: MAJORITY Appropriation: NO Fiscal Committee: YES Local Program: YESBill Text
The people of the State of California do enact as follows:
SECTION 1.
Section 19969.3 of the Health and Safety Code is amended to read:19969.3.
“Design approval agency” means a private organization meeting the requirements specified in regulations of the department to perform evaluation of factory-built components.SEC. 2.
Section 19970.1 is added to the Health and Safety Code, to read:19970.1.
(a) “Factory-built component” means a volumetric modular unit, panelized system, or assembly that bears the insignia of the department that is either wholly manufactured or is in substantial part manufactured at an offsite location to be wholly or partially assembled onsite in accordance with building standards published in the California Building Standards Code and other regulations adopted by the commission pursuant to Section 19990, and is manufactured in such a manner that all concealed parts or processes of manufacture cannot be inspected before installation at the building site without disassembly, damage, or destruction of the component.(b) “Factory-built component” does not include a mobilehome, as defined in Section 18008, a recreational vehicle, as defined in Section 18010, or a commercial modular, as defined in Section 18012.5.
SEC. 3.
Section 19971 of the Health and Safety Code is amended to read:19971.
“Factory-built housing” means a residential building with a factory-built ratio of at least 15 percent, where at least two-thirds of the new or converted square footage is designated for residential use.SEC. 4.
Section 19971.1 is added to the Health and Safety Code, to read:19971.1.
(a) For the purpose of this section, the following definitions apply:(1) “Cost of factory-built components” means the total cost of manufacturing and applicable sales tax of factory-built components, exclusive of transportation costs.
(2) “Cost of vertical construction” means the total direct hard costs, inclusive of labor and materials, for the scope of construction work within the footprint of a structure, including foundations and excluding earthwork and ground improvements. Direct hard costs do not include a general contractor’s general conditions, general requirements, insurances, overhead, or
profit.
(3) “General conditions” means the general contractor’s project-specific indirect costs required to manage, supervise, and execute the work.
(4) “Insurances” means the general contractor’s general liability, automotive, and workers’ compensation insurances.
(5) “Overhead” means the general contractor’s business operating expenses that are not directly attributable to a specific project but are necessary to run the company as a whole.
(6) “Profit” means the general contractor’s fee for executing the work.
(b) “Factory-built ratio” means the ratio, expressed as a percentage, of the cost of
factory-built components to the cost of vertical construction calculated on the basis of a detached structure, as estimated at the time of plan submission to the department, calculated by dividing the cost of factory-built components by the cost of vertical construction, then multiplying by 100 to achieve a percentage.
SEC. 5.
Section 19972 of the Health and Safety Code is amended to read:19972.
“First user” means the person, firm, or corporation who initially installs factory-built housing within this state. A person who subsequently purchases factory-built housing is not a first user within the meaning of this definition.SEC. 6.
Section 19975.1 of the Health and Safety Code is amended to read:19975.1.
“Local inspection agency” means the building department of a city, county, or city and county, which has been certified by the department, and which has assumed responsibility for inspection of in-plant manufacture as provided by Section 19991.1.SEC. 7.
Section 19976.05 of the Health and Safety Code is amended to read:19976.05.
“Quality assurance agency” means a private organization meeting the requirements specified in regulations of the department to perform in-plant inspections of the manufacture of factory-built components.SEC. 8.
Section 19993 of the Health and Safety Code is amended to read:19993.
(a) (1) Local use zone requirements, local design standard requirements, local flood resistant control standards, and local wildfire safety building requirements are hereby specifically and entirely reserved to local jurisdictions notwithstanding any requirement of this part.(2) Local use zone requirements, local design standard requirements, local flood resistant control standards,
and local wildfire safety building requirements imposed on factory-built housing pursuant to the authority granted by this subdivision shall not vary substantially from the requirements imposed on other residential buildings of similar size.
(3) The Legislature finds and declares that Chapter 16 of the California Building Standards Code robustly addresses regional variations in snow load (Section 1608 of Title 24 of the California Code of Regulations) and wind pressure (Section 1609 of Title 24 of the California Code of Regulations).
(b) (1) A city, county, or city and county shall not impose or enforce building standards that exceed the state
minimum building standards in the California Building Standards Code
on a factory-built housing construction project.
(2) If a development project includes factory-built housing and other structures that are not factory-built housing, this subdivision shall apply only to the factory-built housing.
(c) For the purposes of this section, “local flood resistant control standards” means Appendix (G) of Part 2 of Title 24 of the California Building Code incorporated by a city, county, or city and county.
