California ADU laws, decoded.
California has some of the most permissive ADU laws in the country. Ministerial approval is required within 60 days, HOAs can't block you, and parking requirements are waived on most lots near transit. Here's what applies in 2026 — in plain English.
Ministerial approval within 60 days
Qualifying ADU applications must be approved ministerially — without a public hearing or discretionary review — within 60 days of a complete application. Your city can extend the timeline only with written justification.
Size guardrails
Detached ADUs up to 1,200 sq ft are protected statewide. Attached ADUs can be up to 50% of the primary dwelling. JADUs are capped at 500 sq ft. Cities cannot enforce a smaller size unless they provide written justification.
Setbacks
Side and rear setbacks are capped at 4 ft for ADUs. Cities cannot require larger setbacks. Front-yard setbacks usually match the primary home.
Parking
No replacement parking required when converting a garage to an ADU. No new parking required for ADUs near transit. A majority of California urban and suburban lots fall within the half-mile transit exemption.
Owner-occupancy
For detached and attached ADUs, state law prohibits owner-occupancy requirements through 2030. JADUs still require owner-occupancy statewide.
HOAs
HOAs cannot prohibit an ADU on a single-family residential lot (Civil Code §4751). They can impose reasonable aesthetic guidelines, but can't reject the project outright.
Impact fees
ADUs under 750 sq ft are exempt from most impact fees. Larger ADUs are charged proportionally to size. Utility connection fees still apply.
Sale separately (AB 1033)
A small number of California cities allow ADUs to be sold separately from the primary home as condos. Check your city.
This is a plain-English summary, not legal advice. ADU rules change frequently — before you invest in plans, verify with your local planning department or an ADU-focused attorney.
California ADU law FAQs.
California requires cities to approve qualifying ADU applications ministerially — meaning without discretionary review — within 60 days. This is why California ADU permitting is faster than typical residential construction.
Run the numbers for your lot.
Now that you know the rules, see what an ADU could cost and earn on your property.