ADU Ministerial Approval Checker
If your plans meet these objective state standards, your city must approve them — no hearing, no CEQA review, no subjective design veto.
California state law sets objective size, height, and setback standards for ADUs that every city must honor. If your proposed ADU meets them, your city must approve it ministerially within 60 days — no discretionary hearing, no CEQA review, and no denial based on subjective design preferences.
Enter your ADU's planned dimensions to see if it clears the state's ministerial-approval standards.
ADU Ministerial Approval Checker
Ministerial Approval Result
How this is calculated
This tool checks your plans against the state's objective ADU standards on three axes:
- Size. A detached ADU up to 1200 sq ft is state-protected, and no city can cap size below 850 sq ft, or 1000 sq ft for a unit with 2+ bedrooms.
- Height. A detached ADU is protected up to 16 feet generally, or 18 feet near transit/multifamily housing. An attached ADU is protected up to 25 feet or the primary home's allowed height, whichever is lower.
- Setback. At least 4 feet from side and rear property lines.
If your plans clear every applicable standard, your city must process the application ministerially. If they don't, your ADU can still likely be built — it just may fall under your city's discretionary review process instead of the fast-track ministerial path, and local rules will apply more heavily.
Units of 750 sq ft or less also skip most local impact fees and school developer fees under a separate state provision.
Frequently Asked Questions
What does "ministerial approval" mean for an ADU?
It means your city or county must approve or deny the application based on objective standards only — no discretionary public hearing, no CEQA environmental review, and a decision within 60 days. A qualifying ADU can't be denied based on subjective design preferences or neighbor objections.
How big can my ADU be under state law?
A detached ADU up to 1,200 square feet is protected regardless of local zoning. A city cannot set its maximum ADU size below 850 square feet (or 1,000 square feet for a unit with more than one bedroom).
What setback do I need for an ADU?
State law sets a floor of 4 feet from the side and rear property lines for a new detached ADU. There's generally no front setback requirement imposed by state ADU law itself, though other zoning rules may still apply to the front of a lot.
How tall can an ADU be?
A detached ADU is generally protected up to 16 feet, rising to 18 feet within a half-mile of transit or on a lot with an existing multifamily building, and up to 25 feet in some cases where the roof pitch matches the primary home. An attached ADU can go up to 25 feet or match the height allowed for the primary home, whichever is lower.
Can my city deny my ADU application for looking wrong or being unpopular with neighbors?
No. If your proposed ADU meets the objective state standards, the city cannot deny it for subjective design reasons or neighbor opposition — approval must be ministerial, based only on the objective standards that apply.
This tool provides an educational estimate only and is not legal advice. Local ordinances, lot coverage rules, fire/utility access requirements, and historic district overlays can add requirements beyond these state minimums — confirm your exact plan with your city's planning department before applying.