California enacted four ADU laws in 2025 that take effect for 2026: AB 462, AB 1154, SB 9 and SB 543. Most apply on January 1, 2026. Together they speed permit review to a 15 business day completeness check, ease the junior ADU owner occupancy rule, and add state enforcement of local ADU ordinances.
Last verified: September 25, 2026 against the California Legislature bill text and history (leginfo.legislature.ca.gov) and the recodified Government Code Section 66310 and following.
An accessory dwelling unit, or ADU, is a second, smaller home on a lot that already has a house. A junior ADU, or JADU, is a unit of up to 500 square feet created inside the walls of an existing house. This page tracks what California changed for 2026 and 2027, bill by bill, with the effective date and Government Code section for each change.
What are the new California ADU laws for 2026?
California enacted four ADU laws in 2025. Governor Newsom signed all four on October 10, 2025. Three take effect on January 1, 2026, and one took effect immediately because it is an urgency statute.
| Bill | Effective date | What it changed | Government Code | Source |
|---|---|---|---|---|
| AB 462 (Lowenthal) | October 10, 2025 (urgency) | Sets a 60 day deadline for coastal development permits for ADUs, and lets a disaster county issue occupancy for a detached ADU before the main house is rebuilt | 66328, 66329 | Ch. 491, Statutes of 2025 |
| AB 1154 (Carrillo) | January 1, 2026 | JADU owner occupancy now applies only when the JADU shares sanitation with the main house, and a JADU rental must be longer than 30 days | 66333 | Ch. 507, Statutes of 2025 |
| SB 9 (Arreguin, 2025) | January 1, 2026 | Adds state enforcement: a city must send its ADU ordinance to HCD within 60 days and cure defects within 30 days, or the ordinance is null and void | 66326 | Ch. 510, Statutes of 2025 |
| SB 543 (McNerney) | January 1, 2026 | Requires a 15 business day completeness review, defines interior livable space, and ties the impact fee waiver to that definition | 66311, 66313, 66317, 66321, 66323 | Ch. 520, Statutes of 2025 |
AB 462: coastal and disaster ADUs
AB 462 is an urgency statute, so it took effect the day it was signed, October 10, 2025. AB 462 requires a local agency to approve or deny a coastal development permit for an ADU within 60 days of a complete application. AB 462 also lets a county under a state of emergency issue a certificate of occupancy for a detached ADU before the primary dwelling, where the primary home was destroyed in the emergency and the ADU passed inspection. AB 462 amended Government Code Sections 66328 and 66329.
AB 1154: junior ADU owner occupancy
AB 1154 narrowed the junior ADU owner occupancy rule. Before AB 1154, a city could require the owner to live on site for any JADU. Under AB 1154, effective January 1, 2026, owner occupancy applies only when the JADU shares sanitation facilities with the existing house. A JADU with its own bathroom is exempt from the owner occupancy requirement. AB 1154 also requires that a JADU rental be for a term longer than 30 days, which blocks short term rental use. AB 1154 amended Government Code Section 66333.
SB 9 (2025): state enforcement of local ADU rules
Two different laws share the number SB 9. The SB 9 that took effect January 1, 2026 is the 2025 bill by Senator Arreguin, and it is an ADU enforcement law. It is not the 2021 SB 9 lot split law by former Senator Atkins, which is a separate statute covered on our SB 9 lot splits page. The 2025 SB 9 requires a local agency to submit its ADU ordinance to the Department of Housing and Community Development, known as HCD, within 60 days. If the agency does not submit the ordinance, or does not cure HCD findings within 30 days, the ordinance is null and void and the statewide default ADU standards apply. The 2025 SB 9 amended Government Code Section 66326.
SB 543: faster permits and how size is measured
SB 543 is the largest of the four bills. SB 543 requires a permitting agency to tell an applicant within 15 business days whether an ADU application is complete. SB 543 defines interior livable space as space in a dwelling intended for human habitation. That definition sets the basis for the 500 square foot junior ADU cap and the 750 square foot impact fee threshold. SB 543 renumbered the impact fee section, so the ADU impact fee waiver now sits at Government Code Section 66311.5. SB 543 amended Government Code Sections 66311, 66313, 66317, 66321 and 66323, effective January 1, 2026.
What changed on January 1, 2026?
Ministerial approval means a city must approve a qualifying application without discretionary review or a public hearing. By right means the use is allowed without a special permit. Here is what changed for California ADUs on January 1, 2026, one point at a time.
- A city must now issue a completeness determination within 15 business days of receiving an ADU or JADU application (SB 543, Gov. Code 66317).
- A junior ADU with its own bathroom no longer triggers an owner occupancy requirement (AB 1154, Gov. Code 66333).
- A junior ADU rental must be for more than 30 days (AB 1154, Gov. Code 66333).
- A city that fails to file a compliant ADU ordinance with HCD loses that ordinance to the statewide default standards (SB 9 of 2025, Gov. Code 66326).
- The impact fee waiver for an ADU of 750 square feet or less is measured by interior livable space (SB 543, Gov. Code 66311.5).
The 60 day ministerial approval deadline for a complete ADU application did not change. That deadline remains at Government Code Section 66317, and a city that misses it triggers deemed approval.
What changes in 2027?
No further statewide California ADU changes are scheduled as of September 25, 2026. The 2026 changes above are the current state of the law. We recheck the California Legislature each session and will update this page when a 2027 bill is chaptered.
A short history of California ADU law
California rewrote its ADU law repeatedly before the 2026 bills. The table below lists the earlier statutes that built the current framework. Their text is superseded, but their substance now lives in the Government Code Section 66310 series after the 2025 recodification.
| Bill | Year | What it did | Source |
|---|---|---|---|
| SB 1069 (Wieckowski) | 2016 | The modern ADU liberalization law: cut parking and streamlined approval | Ch. 720, Statutes of 2016 |
| SB 13 (Wieckowski) | 2019 | Cut impact fees for smaller ADUs and eased owner occupancy | Ch. 653, Statutes of 2019 |
| AB 68 (Ting) | 2019 | Expanded ADU permissions and ministerial approval | Ch. 655, Statutes of 2019 |
| AB 881 | 2019 | Removed several owner occupancy and parking barriers | Ch. 659, Statutes of 2019 |
In 2025 California moved ADU law out of Government Code Section 65852.2 into a new dedicated chapter beginning at Government Code Section 66310. Bills chaptered in 2023 or earlier, such as AB 1033, still reference the old section numbers, but the operative text now lives in the 66310 series.
How the 2026 bills connect to other California ADU laws
The 2026 bills sit alongside three other recent ADU laws, each covered on its own page.
- The 2021 SB 9 lot split law is a different statute from the 2025 SB 9 above, and it governs splitting a single family lot rather than ADU standards.
- AB 1033 lets a city opt in to allowing an ADU to be sold separately as a condominium.
- SB 1211 allows up to eight detached ADUs on a lot with an existing multifamily building.
For the full statewide rules on size, setbacks, height, parking and fees, see the California ADU law and permits pillar. For how big an ADU can be under these rules, see our California ADU size limits page.
Frequently Asked Questions
What are the new ADU laws in California for 2026?
California enacted four ADU laws in 2025: AB 462, AB 1154, SB 9 and SB 543. AB 462 took effect on October 10, 2025 as an urgency statute. AB 1154, SB 9 and SB 543 took effect on January 1, 2026.
When did the new California ADU laws take effect?
AB 462 took effect immediately on October 10, 2025. AB 1154, the 2025 SB 9 and SB 543 all took effect on January 1, 2026.
Does California still require owner occupancy for an ADU?
No. California does not allow a city to require owner occupancy for an ADU, under Government Code Section 66315. A junior ADU can still trigger owner occupancy, but only when it shares sanitation with the main house, after AB 1154.
Is the 2026 SB 9 the same as the 2021 SB 9 lot split law?
No. The 2021 SB 9 is a lot split and two unit law. The 2025 SB 9 is a separate ADU enforcement law that took effect January 1, 2026. They share a bill number but are different statutes.
How fast must a California city review an ADU application in 2026?
A California city must tell you within 15 business days whether your ADU application is complete, under SB 543. The city must then approve or deny a complete application within 60 days, under Government Code Section 66317, or the application is deemed approved.
What changes for California ADUs in 2027?
No further statewide California ADU changes are scheduled as of September 25, 2026. The January 1, 2026 changes are the current law.
Sources
- California Legislature, AB 462 (2025), text and history: https://leginfo.legislature.ca.gov/faces/billTextClient.xhtml?bill_id=202520260AB462
- California Legislature, AB 1154 (2025), text and history: https://leginfo.legislature.ca.gov/faces/billTextClient.xhtml?bill_id=202520260AB1154
- California Legislature, SB 9 (2025), text and history: https://leginfo.legislature.ca.gov/faces/billTextClient.xhtml?bill_id=202520260SB9
- California Legislature, SB 543 (2025), text and history: https://leginfo.legislature.ca.gov/faces/billTextClient.xhtml?bill_id=202520260SB543
- California Government Code, Section 66310 and following (ADU law): https://leginfo.legislature.ca.gov/faces/codes_displayText.xhtml?division=1.&chapter=13.&lawCode=GOV&title=7.
- California Legislature, SB 9 (2021, lot splits): https://leginfo.legislature.ca.gov/faces/billTextClient.xhtml?bill_id=202120220SB9
- California HCD, ADU Handbook (state agency guidance): https://www.hcd.ca.gov/building-standards/adu/handbook
Disclaimer
This page is general information, not legal advice. ADU law changes often and cities apply it differently. Confirm the current rules with your local planning department before you build.
Related ADU laws
Other laws and rules in the same silo, kept in step as each one goes live.