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Guide

How long an ADU permit takes in California

State law doesn't promise a fast permit, but it does put the city on a clock at three points. Knowing which clock is running tells you whether you're waiting on the city or the city is waiting on you.

At a glance

15 business days
for the city to decide if your application is complete1
60 days
to approve or deny a completed application1
60 business days
for a final answer on an appeal1

Key points

  • The city has 15 business days to tell you in writing whether your application is complete.1
  • Once it holds a completed application, it has 60 days to approve or deny.1
  • An appeal must be decided within 60 business days.1
  • Every resubmittal restarts the 15-business-day completeness clock.1

Clock one: is the application complete?

From the day the permitting agency receives your application, it has 15 business days to decide whether the application is complete and to tell you so in writing.1 This step exists because of SB 543, which rewrote the review procedure with effect from January 1, 2026.1

"Permitting agency" is wider than the planning counter. The definition takes in any body involved in reviewing the permit that has no substitute, and it names utilities and special districts alongside planning and building departments.2 In practice that means a water district sitting on your file is on the same clock.

If the agency says nothing within the 15 business days, the application is treated as complete.1

Clock two: approve or deny

When the lot already has a house or a multifamily building on it, the agency has 60 days from receiving a completed application to approve or deny it.1 The decision is ministerial, so there is no hearing and no discretionary review.1

Note the two units. Completeness is counted in business days. The decision period is written simply as 60 days.

Three things change this clock:

  • You ask for a pause. If the applicant requests a delay, the 60 days stop running for as long as the delay lasts.1
  • You're building the main house at the same time. The agency may hold the ADU decision until it has decided the new home.1
  • The city runs out of time. The statute says that if the local agency has neither approved nor denied a completed application within 60 days, the application is deemed approved.1

Clock three: the appeal

If your application is found incomplete or is denied, the agency has to give you a way to appeal in writing to its governing body.1 It then has 60 business days from receiving your appeal to give a final written determination.1 A city that offers two levels of appeal doesn't get extra time for the second.1

Junior ADUs run on similar clocks

Junior ADUs have their own section of the code. It carries the same 15-business-day completeness review3 and a 60-day decision period where there is an existing single-family home.3

Where the time really goes

The statutory periods add up to roughly three months for a clean application. Most of the calendar time in a real project sits outside them: preparing drawings, waiting on a survey or an energy report, and turning around each incomplete notice. Every resubmittal opens a fresh 15-business-day review1, so two rounds of missing items can add six weeks before the 60-day period has even begun.

Common questions

Does the 60-day clock start on the day I submit my ADU application?

Not necessarily. The 60 days run from the date the agency receives a completed application1, and completeness is decided first, within 15 business days.1 If you receive an incomplete notice, see how to answer it.

Are the 15 days calendar days or business days?

Business days.1 Agencies spell out what that means for them: Menlo Park counts days its City Hall is open4, and Los Angeles County's memo excludes weekends and state holidays.5 The county's approach is on our Los Angeles County page.

What happens if the city never answers?

Silence on completeness means the application is deemed complete.1 Silence on a completed application for 60 days means the statute treats it as deemed approved.1 Take legal advice before relying on a deemed approval. The provisions are summarized under what SB 543 left alone.

Keep reading

About this page

Written by
The Lotline Editorial Team. Editorial policy
Where it comes from
We wrote this from material published by California Legislative Information and City of Menlo Park and Los Angeles County Department of Regional Planning. You'll find each document, and the part we used, under References below.
How it was checked
Before publishing, we checked each statement against the original wording of its source. How we work
Last reviewed
. Rules and city procedures change, so confirm current requirements with your permitting agency.
Corrections
Email support@lotlinepermits.com. We check every report against the document and fix what is wrong.

References

  1. 1California Government Code, Title 7, Division 1, Chapter 13, Article 2 (Sections 66314 to 66331)California Legislative Information. Read on November 10, 2026.Cited: § 66317(a)(2)(A); § 66317(a)(3); § 66317(d)(2); § 66317(a)(2)(E); § 66317, amendment note; § 66317(a)(2)(F); § 66317(a)(1); § 66317(d)(1).
  2. 2California Government Code, Title 7, Division 1, Chapter 13, Article 1 (Sections 66310 to 66313.5)California Legislative Information. Read on November 10, 2026.Cited: § 66313(k).
  3. 3California Government Code, Title 7, Division 1, Chapter 13, Article 3 (Sections 66333 to 66339.5)California Legislative Information. Read on November 10, 2026.Cited: § 66335(a)(2)(A); § 66335(a)(3).
  4. 4Accessory Dwelling Unit (ADU) Application ChecklistCity of Menlo Park, Community Development, Planning Division. Dated March 19, 2026. Read on November 10, 2026.Cited: page 1, General Information.
  5. 5Accessory Dwelling Units: Senate Bill 543 and Assembly Bill 1154 (memo to staff)Los Angeles County Department of Regional Planning. Dated December 30, 2025. Read on November 10, 2026.Cited: page 1, footnote 1.

General information, not legal advice. Read the disclaimer.