Each January a new set of ADU bills takes effect in California. The 2026 batch is less about adding units and more about forcing cities to say yes faster. Here is what changed and what it means for a homeowner or investor planning a build this year.
SB 543: deemed complete, measured from the inside
SB 543 tightens the ADU permit process. A city must decide whether your application is complete within 15 business days. If it misses that window, the application is deemed complete. When the city does flag missing items it has to give you a written list, and on resubmittal it can only review the items it already flagged. You also get a right to appeal an incompleteness determination.
Two smaller provisions matter a lot in practice. The 800 square foot state-exempt detached ADU is now measured as interior livable space, so exterior walls and stairs no longer eat into your allowance. And ADUs and JADUs under 500 square feet are exempt from school impact fees.
AB 1154: JADU owner-occupancy narrowed
Junior ADUs have been the one ADU type that still required the owner to live on the property. From 2026, that requirement applies only when the JADU shares a bathroom with the main house. A JADU with its own bathroom no longer triggers owner-occupancy, which makes JADUs viable for investors for the first time. Read the full JADU guide.
AB 462: coastal zone and disaster ADUs
In the Coastal Zone, cities with a certified Local Coastal Program must act on an ADU's Coastal Development Permit within 60 days; otherwise the Coastal Commission gets 60 days, and the ADU is deemed approved if neither acts. In counties under a disaster proclamation issued on or after February 1, 2025 (Los Angeles and Ventura after the January 2025 fires), a permitted detached ADU can receive a certificate of occupancy before the primary home is rebuilt, so families can live on their lot during reconstruction.
Enforcement: HCD gets teeth
A 2025 bill also numbered SB 9 (not to be confused with the 2021 lot-split law) makes a local ADU ordinance void if it is not submitted to HCD within 60 days of adoption, or if the city ignores HCD's deficiency findings for 30 days. AB 712 adds fines of $10,000 per unit, with a $50,000 minimum for small projects, when an agency violates state housing law after a warning. In short: the state ADU rules now override a non-compliant city ordinance in practice, not just on paper.
Still in force from 2025
- SB 1211: up to eight detached ADUs on multifamily lots.
- AB 976: no owner-occupancy requirement for ADUs, made permanent.
- AB 1332: every city must offer pre-approved ADU plans and act on them within 30 days.
- AB 2533: amnesty path for ADUs built without permits before 2020.
- AB 1033: cities may allow ADUs to be sold separately as condos.
The 60-day clock, in one paragraph
Submit a complete ADU application and the city has 60 days to approve or deny it. There is no public hearing, no design review, and no CEQA. If the city does nothing in 60 days, the application is deemed approved. Parcy builds that timeline into every analysis so you can plan financing and construction around a date, not a hope.
Frequently asked questions
What ADU laws changed in California in 2026?
SB 543 (15-business-day completeness review, deemed-complete rule, interior measurement of the 800 sq ft exemption, school fee exemption under 500 sq ft), AB 1154 (JADU owner-occupancy only when a bathroom is shared), and AB 462 (60-day coastal permits and disaster-area ADU occupancy).
How long does ADU approval take in California?
A city must act within 60 days of a complete application. Under SB 543, completeness itself must be determined within 15 business days.
Do I have to live on the property to rent out my ADU?
No. AB 976 permanently removed owner-occupancy requirements for ADUs. From 2026, JADUs require owner-occupancy only when they share a bathroom with the main home.
Informational only. Not legal, architectural, or investment advice. Confirm current rules with your local planning department.