AB 1070
Building Codes for “Missing Middle” Housing
AB 1070 will direct state agencies to study how using the residential building code for small, multi-family home projects could accelerate the construction of “missing middle” housing.
Under current California building codes, small apartment buildings (from 3-10 homes) are treated the same as large, commercial developments. When developers build a single-unit home or a duplex, they follow practical residential rules designed for human habitation.
But when the total number of homes crosses over to three or more, builders must follow commercial building codes that are meant for much larger apartment complexes – and even shopping malls, business towers, and retail centers. These types of buildings require industrial-grade plumbing, fire protection, and other building materials that are beyond what’s necessary for small residential buildings – adding significantly to construction costs, and sometimes even killing new homes altogether.
AB 1070 seeks to correct the imbalance in our building codes by directing the state to study how buildings with 3 to 10 homes could follow the residential building codes meant for housing.
Updates
| Feb 20, 2025 | Introduced |
| Apr 3, 2025 | Amended in Assembly · Became a two-year bill |
| Jan 5, 2026 | Amended in Assembly |
| Jan 26, 2026 | Passed Assembly floor 75–0 · Now in Senate |
Authors
- Chris Ward (AD 78)
Sponsors
- California YIMBY
- Casita Coalition
- Council of Infill Builders
Resources
AB 1070 Fact Sheet
A closer look at the bill’s details.