Building a backyard home in California just got simpler. A package of state laws effective January 1, 2026, including AB 1154, SB 543, SB 9, and AB 462, streamlines Accessory Dwelling Unit (ADU) permitting statewide. Cities must now confirm within 15 business days whether an ADU application is complete, and decide on complete applications within 60 days. The long-standing rule requiring homeowners to live on the property has been permanently eliminated for standard ADUs (made permanent by AB 976), meaning owners can rent out both the main house and the ADU without residing on-site.
Detached ADUs can reach up to 1,200 square feet, and California law overrides local ordinances that try to impose stricter limits. Junior ADUs (units built within the existing home) are capped at 500 square feet, with owner-occupancy only required when the unit shares a bathroom with the main house.
What this means for OC homeowners
More ADU projects are moving forward across Orange County, and most come with a practical side effect, a new structure means new access points, and new access points mean new gates and fencing to separate the ADU's entrance, parking, or yard space from the main home.
