Note: This is the seventh update in our series covering AB 130 and SB 131, two bills that work substantive changes to the California Environmental Quality Act (CEQA) and California housing law. Click here to learn more about other recent updates in these bills.
On June 30, 2025, Gov. Gavin Newsom signed two budget trailer bills—AB 130 and SB 131. These bills, which took effect immediately, create major changes to the California Environmental Quality Act (CEQA) and state housing law. This alert focuses on changes made by AB 130 to local agencies’ ability to modify California Building Standards Code (“Building Code”) standards.
The inclusion of these changes in a budget trailer bill marks a notable deviation from the general practice of this administration of not including significant policy changes in budget language. A measure earlier in the session, AB 306 by Assemblymember Nick Schultz (D-Burbank), would have imposed a moratorium on the adoption or modification of new state and local building standards affecting residential units. The measure has been paused for now, but it faced significant opposition from a large coalition of environmental groups and building code officials in its first committee test in the Assembly.
The Building Code includes certain construction and occupancy standards for residential buildings that are approved and adopted by the California Building Standards Commission (“Commission”) on a triennial cycle. State housing law also includes standards as well. Prior to AB 130, a city or county could make changes to those building standards or adopt more restrictive standards, including green building standards, if the city/county made an express finding that the change or additional restriction was reasonably necessary due to local climatic, geological or topographical conditions.
By amending Health & Safety Code (“Health & Saf. Code”) sections 17958, 17958.5, 17958.7, and 18941.5, however, AB 130 prohibits a city or county, from making changes or adopting more restrictions to the State Housing Law and Building Code standards applicable to residential units unless one of the following conditions is met:
- The change is substantially equivalent to a change previously filed by the city/county and was in effect as of Sept. 30, 2025 (id., §§ 17958, 17958.5, 17958.7, 18941.5);
- The Commission deems the change necessary as an emergency standard to protect health and safety (id.);
- The change relates to home hardening (id.);[1]
- The building standard relates to home hardening and is proposed for adoption by a fire protection district (id.);
- The change is necessary to implement a local code amendment that is adopted to align with a general plan approved on or before June 10, 2025, and that permits mixed-fuel (i.e., electric and natural gas, etc.) residential construction consistent with federal law while also incentivizing all-electric construction as part of an adopted greenhouse gas emissions reduction strategy (id.); or
- Where the change is a modification rather than an additional restriction, the change is related to administrative practices, is proposed for adoption during the time between Building Code updates, and exclusively results in any of the following:
- Reductions in time for a local agency to issue a post-entitlement permit;
- Alterations to a local agency’s post-entitlement fee schedule;
- Modernization of, or adoption of, new permitting platforms and software utilized by the local agency;
- Reductions in cost of internal operation for a local agency; or
- Establishment, alteration or removal of local programs related to enforcement of building code violations or complaints alleging building code violations (id., §§ 17958, 17958.5, 17958.7).
If the change satisfies one or more of these conditions, the governing body of a city or county shall make express findings that such change is reasonably necessary because of local climatic, geological or topographical conditions, and submit such findings with the proposed change to the Commission. (Id., § 17958.7.) The Commission must reject a change that does not satisfy one of these conditions. (Ibid.)
These restrictions on local agency authority will last from October 1, 2025, to June 1, 2031, unless further extended. (Id., §§ 17958(b), 17958.5(c), 17958.7(c), 18941.5(c).)
Similarly, state agencies are prohibited from updating the building standards related to residential units unless one of the following conditions is met:
- The Commission deems the change necessary as an emergency standard to protect health and safety;
- The building standard is an amendment by the State Fire Marshal to a building standard within the California Wildland-Urban Interface Code;
- The building standard is proposed for adoption in relation to standards regarding single-exit, single-stairway, three-story-plus apartments;
- The building standard is proposed for adoption in relation to adaptive reuse residential projects, water reuse systems or water quality standards for reuse of non-potable water in multifamily residential, commercial and mixed-use buildings;
- The building standard is necessary to: ensure the latest editions of the model codes are incorporated into the triennial edition of the Building Code; incorporate errata or emergency updates to the national model codes; or incorporate updates to accessibility requirements that align with minimum federal accessibility laws, standards and regulations; or
- The building standard would take effect on or after Jan. 1, 2032.
(Id., §§ 18929.1(c), 18930(g).)
The inclusion of a carve-out for “single stair reform” is noteworthy. The push to update the building code to allow for a single stairwell in medium-density multifamily housing has recently been a cause célèbre among abundance advocates and YIMBY activists alike. Currently, the residential building code in most U.S. cities requires two stairwells for multifamily developments, which can significantly limit unit counts and design options for smaller projects. Indeed, it effectively renders many midrise projects on small or irregular lots infeasible. Advocates have been pushing for reform in this space and have started to make headway with code changes in some major metropolitan areas. When AB 306 proposed to put a moratorium on building code changes, the general support from the housing community was tempered by a concern that the policy could derail ongoing efforts to influence the Building Standards Commission in support of reform. That the single stair received a specific mention in AB 130 is a signal of institutional support from the governor’s office and legislative leadership, and we are likely to see additional legislative proposals next year looking to capitalize on this momentum.
As for the Building Code at large, AB 130 limits some of the periodic changes that the Commission may make. Previously, the Commission was required to publish an updated Building Code every three years and supplement, as necessary, in the intervening period. Now, the Commission is only permitted to adopt changes during the intervening period as necessary for the following limited reasons:
- Editorial or clarity reasons;
- Certain technical updates to existing requirements to support implementation of the requirement;
- Emergency building standards;
- Amendments by the State Fire Marshal to specified building standards within the California Wildland-Urban Interface Code;
- To incorporate errata or emergency updates to the national model codes;
- Certain changes or modifications to administrative practices; and
- Building standards necessary to incorporate minimum federal accessibility requirements.
(Health & Saf. Code, § 18942(a)(2).)
AB 130 also updates the Building Code to expand the definition of “model code” to include the latest edition of the International Wildland-Urban Interface Code of the International Code Council. (Id., § 18916(h).)
Moving forward, AB 130 also requires state and local building standards in effect at the time an application for a building permit is submitted for a residential dwelling based on a model home design approved under those standards to apply to all future residential dwellings based on that approved model home design in the same jurisdiction, unless the design substantially changes or 10 years have passed since the original building permit was approved. (Id., § 18938.5(d).) This provision expands the previous rule, which stated that, no matter the project, applicable building standards are those in effect at the time an application for a building permit is submitted.
Taken together, these amendments imposed by AB 130 are designed to further streamline the construction of residential housing to address the state’s housing crisis. It remains to be seen to what extent these changes accelerate the pace of housing construction throughout the state.
[1] AB 130 does not clarify whether the change must be for fire protection or other purposes.
