Accessory Dwelling Units: ordinances.

Bill renumbered as Chapter 510 with governor approval date of October 10, 2025 added

Senate and Assembly passage headers, signature lines, and Private Secretary transmittal block removed as part of standard chaptering process

Official 'STATE OF CALIFORNIA AUTHENTICATED ELECTRONIC LEGAL MATERIAL' header added

The entire amendment to Government Code Section 66316 was dropped from the enrolled version. That section would have required all ADU ordinances to contain only ministerial approval provisions (no discretionary processes) and would have automatically invalidated any existing local ADU ordinance that failed to meet those requirements.

The bill's scope narrowed from amending two sections of the Government Code (66316 and 66326) to amending only one section (66326). The enrolled version no longer addresses the content requirements for ADU ordinances, focusing solely on the administrative submission and compliance review process.

A provision making an ADU ordinance null and void if the local agency failed to submit it within 60 days or failed to respond to state findings within 30 days was removed from Section 66316. A similar nullification penalty remains in Section 66326(d), but it is now the only enforcement mechanism in the bill.

Section 66315 now explicitly states that no additional standards may be imposed 'including an owner-occupant requirement,' making the prohibition on owner-occupancy rules more specific and harder for local agencies to argue around.

The bill's sections were reordered: Section 66315 (maximum standards) and Section 66322 (parking and owner-occupancy prohibitions) now appear before Section 66316 (ministerial approval and null-and-void enforcement), so the standards are established before the enforcement mechanism.

The fiscal committee designation changed from 'no' to 'yes' and the state-mandated local program designation changed from 'no' to 'yes,' acknowledging that the bill imposes new duties on local governments that trigger reimbursement analysis under the California Constitution.

Removed the amendment to Section 66322 that prohibited local agencies from imposing parking standards for ADUs in six specific situations (near transit, historic districts, part of primary residence, on-street permits not offered, car share nearby, simultaneous permit applications).

Removed the amendment to Section 66315 that established maximum standards for evaluating proposed ADUs on lots with single-family dwellings.

Removed the prohibition on local agencies imposing owner-occupancy requirements for proposed or existing accessory dwelling units.

Removed the provision preventing local agencies from denying ADU permits due to nonconforming zoning conditions, building code violations, or unpermitted structures that do not threaten public health and safety.

Added a new provision in Section 66326(c)(2) allowing the Department of Housing and Community Development to consider whether a local agency had adopted a compliant ordinance between January 1, 2017 and January 1, 2020 before notifying the Attorney General of a violation.

Clarified in Section 66326(d) that the null-and-void consequence for noncompliance explicitly includes failure to meet the ordinance submittal requirements of that section itself.

Added Senator McNerney as a coauthor of the bill.

The bill no longer imposes a state-mandated local program. The fiscal committee review requirement was changed from 'yes' to 'no,' and the entire section stating that no reimbursement is required under Article XIIIB of the California Constitution was deleted.

Section 66315 no longer explicitly names 'owner-occupant requirement' as an example of a prohibited additional standard. The prohibition on owner-occupancy requirements remains in Section 66322(b), so this is a redundancy cleanup rather than a policy change.

The three amended sections were reordered: Section 66316 (ministerial approval and null-and-void provisions) now appears first, followed by Section 66315 (maximum standards), then Section 66322 (parking and owner-occupancy prohibitions). The legislative digest was also restructured to present existing law before describing the bill's changes.

New amendment to Government Code Section 66316 requires that ADU ordinances include only ministerial approval provisions and no discretionary processes. Any existing ordinance that fails to meet these requirements is declared null and void, forcing the local agency to apply state standards until it adopts a compliant ordinance.

A local agency's ADU ordinance becomes null and void if the agency fails to submit a copy to the Department of Housing and Community Development within 60 days of adoption, or fails to respond to the department's non-compliance findings within 30 days.

Section 66315 no longer explicitly states that an owner-occupant requirement is prohibited; that language was removed. The prohibition remains in Section 66322(b), so the practical effect is unchanged but the legal basis shifts.

A new provision states that no state reimbursement is required under Article XIII B of the California Constitution because local agencies have authority to levy service charges, fees, or assessments sufficient to cover the mandated program costs.

The bill is now classified as imposing a state-mandated local program (changed from 'no' to 'yes') and requires fiscal committee review (changed from 'no' to 'yes'), reflecting the new enforcement duties placed on local governments.