California ADU 60-Day Permit Rule Explained

What the 60-day rule says

Section 66317(a)(3) requires the permitting agency to approve or deny an application to create or serve an ADU within 60 days from the date it receives a completed application, when there is an existing single-family or multifamily dwelling on the lot. If the agency has not acted within 60 days, the application is deemed approved.

Section 66317(a)(1) adds that an ADU permit is approved ministerially, without discretionary review or a hearing. The city applies its objective standards; it does not hold a public hearing on your ADU.

• The clock starts when the city receives a completed application.
• It applies when a house or multifamily building already stands on the lot.
• If you ask for a delay, the 60 days pause for the length of that delay.

The 15 business day completeness notice

Before the 60 days begin, Section 66317(a)(2) requires the city to decide whether the application is complete and send you written notice within 15 business days of receiving it. If it is incomplete, the notice must list the missing items and explain how to fix them.

When you resubmit, the city cannot ask for an item that was not on that list, and the resubmittal gets the same 15 business day review. If the city misses the 15 business day deadline, the application is deemed complete.

When the city may wait longer

If the ADU application is filed together with an application for a new house or multifamily building on the same lot, the city may hold the ADU decision until it decides on the new building. The ADU is still reviewed without a hearing.

If you are the one who asks for a delay, the 60 day period is paused for the length of the delay you requested.

What happens if the city denies the application

Under Section 66317(b), a city that denies an ADU application must, within the same time period, give you a full set of written comments listing the defective or deficient items and describing how you can fix them. That list is what you respond to on resubmittal.

How to keep your permit on the 60 day track

Submit a complete package the first time and keep the city's written completeness notice. If a notice lists missing items, answer only those items. If the city goes past 15 business days without a notice, or past 60 days after a complete application without a decision, point to Section 66317 in writing.

L Square Design & Build prepares and submits ADU packages and answers plan check comments for homeowners in Orange County and Los Angeles County. Call (949) 374-7980 to talk about your lot.