How Long Does an ADU Permit Take in California? (2026 City-by-City Guide)

How long does an ADU permit take in California? State law says 60 days. Reality says 4 to 16 weeks depending on your city, the quality of your submission, and how many correction rounds your plans go through. Sacramento and San Diego are the fastest major markets at 4 to 8 weeks. Los Angeles is the slowest at 8 to 16 weeks. This guide breaks down realistic permit timelines for each city, explains why the 60-day rule doesn’t always mean 60 days, and shows you how to avoid the delays that add months to your project.

The permit timeline is the part of the ADU process you have the most control over — and the part most homeowners underestimate. A clean submission with complete plans gets approved in weeks. A sloppy submission with missing calculations triggers correction cycles that stretch into months.

City	Standard Plan	Custom Plan	With Corrections
Sacramento	2–4 weeks	4–6 weeks	6–10 weeks
Los Angeles	3–6 weeks	8–12 weeks	12–16+ weeks
San Diego	2–3 weeks	4–6 weeks	6–10 weeks

These are permit review times — from complete submission to approved plans. They do not include the time to design plans (2–6 weeks) or construction (3–10 months). For the full project timeline, see our ADU Permits California guide.

California law (Government Code Section 65852.2) requires cities to approve or deny a complete ADU application within 60 days. SB 543, effective 2025, strengthened this by adding a 15-day completeness check and requiring itemized deficiency lists.

What the law actually says:

• The city has 15 days to determine if your application is complete
• If incomplete, they must issue an itemized list of what’s missing
• Once deemed complete, the 60-day clock starts
• The city must approve or deny within those 60 days

Why it doesn’t work as cleanly as it sounds:

The 60-day clock resets when the city issues corrections. Here’s the typical sequence:

1. You submit plans. City deems them complete (starts 60-day clock).
2. Plan checker reviews and finds code issues. Issues a correction letter.
3. 60-day clock pauses while you revise plans.
4. You resubmit corrected plans. Clock restarts.
5. Plan checker reviews again. May issue more corrections.
6. Repeat until approved.

Each correction cycle adds 2 to 4 weeks — the time for your architect to make revisions plus the time for the city to re-review. A project with two rounds of corrections can easily take 10 to 14 weeks even though the city technically stayed within the 60-day window for each review cycle.

The real insight: The 60-day rule protects you from a city sitting on your application doing nothing. It does not protect you from a slow correction cycle caused by incomplete or non-compliant plans. The quality of your initial submission is what determines your actual timeline.

Sacramento’s Community Development Department processes ADU permits efficiently by California standards. The city has invested in streamlining the ADU review process, and the volume of applications is lower than LA — which means shorter queues.

What to expect:

• Standard plans: 2 to 4 weeks. Sacramento accepts state-compliant pre-approved designs with expedited review.
• Custom plans, clean submission: 4 to 6 weeks. A complete submission with no code issues can be approved on the first review cycle.
• Custom plans with corrections: 6 to 10 weeks. One round of corrections adds 2 to 3 weeks.
• Online submission: Available through the SacPermits portal. Digital submission is faster than in-person.

Sacramento-specific tip: The city’s plan checkers are familiar with common ADU designs. If your architect has permitted ADUs in Sacramento before, they know what the plan checkers look for and can avoid the most common correction triggers. Ask your builder about their Sacramento permit track record.

Find verified Sacramento builders: Sacramento ADU Directory

LADBS (Los Angeles Department of Building and Safety) processes more ADU permits than any other building department in the country. The volume creates backlogs, and LADBS has stricter interpretations of certain code provisions — particularly around hillside construction, fire zones, and Historic Preservation Overlay Zones (HPOZs).

What to expect:

• Standard Plan Program: 3 to 6 weeks. LADBS offers pre-approved ADU designs that skip most of the plan check process. This is the fastest path to a permit in LA.
• Custom plans, clean submission: 8 to 12 weeks. Even a perfect submission takes longer in LA because of reviewer workload.
• Custom plans with corrections: 12 to 16+ weeks. Two rounds of corrections is common for custom ADU plans in LA. Hillside properties can exceed 16 weeks.
• HPOZ overlay: Add 2 to 4 months for Historic Preservation Overlay Zone review if your property is in one. This is a separate design review on top of the standard building permit.
• Fire zone: Properties in Very High Fire Hazard Severity Zones require additional fire department review, adding 2 to 4 weeks.

LA-specific tip: Use the LADBS Standard Plan Program if your project qualifies. The time savings are enormous — 3 to 6 weeks versus 12+ weeks for custom plans. Ask your contractor if they have pre-approved designs on file with LADBS.

Find verified LA builders: Los Angeles ADU Directory

San Diego’s Development Services Department is one of the fastest ADU permitting agencies among California’s major cities. The city has actively promoted ADU construction and invested in reducing review times.

What to expect:

• Standard plans: 2 to 3 weeks. San Diego has pre-approved several prefab and site-built ADU designs with the fastest review times in the state for qualifying projects.
• Custom plans, clean submission: 4 to 6 weeks. First-pass approvals are more common in San Diego than in LA.
• Custom plans with corrections: 6 to 10 weeks. San Diego plan checkers are generally responsive and turnaround on resubmissions is fast.
• Coastal Zone: Properties in the California Coastal Zone (La Jolla, Del Mar, Encinitas, Carlsbad, Oceanside) may require a Coastal Development Permit — add 2 to 6 months for this separate review process.

San Diego-specific tip: San Diego waives development impact fees for ADUs under 750 sq ft. This saves money and also simplifies the fee calculation portion of the permit, which can speed up the process marginally.

Find verified San Diego builders: San Diego ADU Directory

1. Incomplete structural calculations. The number one reason for plan check corrections statewide. Missing foundation details, incomplete lateral load analysis, or improperly detailed connections. Every correction cycle adds 2 to 4 weeks. Solution: use a structural engineer who has done ADU work in your specific city.

2. Title 24 non-compliance. Submitting plans without a compliant energy report, wrong climate zone assumptions, or insulation values that don’t meet code. The Title 24 report is a required attachment — not optional. Solution: hire an energy consultant who runs the calculations before your architect finalizes the plans.

3. Setback violations. Measuring from the wrong reference point — property line vs. easement vs. fence line. A 4-foot setback that’s actually 3 feet 8 inches triggers a correction. Solution: get a licensed site survey before design starts.

4. Missing documents. Unsigned forms, insufficient plan sets, missing soil report, or no Title 24 report attached. The completeness check catches these, but resubmitting adds a week minimum. Solution: use the building department’s submittal checklist and verify every item before submitting.

5. Sewer capacity issues. Some cities require a sewer capacity study or lateral inspection. If the city flags this during review, you need to schedule an inspection and potentially do repairs before the permit can be issued. This can add 2 to 6 weeks depending on the scope.

6. Additional agency reviews. Fire department (for fire zones), Coastal Commission (for coastal properties), HOA design review, or historic preservation review. Each additional agency adds its own timeline on top of the building department review. Know which agencies are involved before you submit.

Use pre-approved standard plans. If your project fits a pre-approved design, you skip most of the plan check process. Available in LA, San Diego, Sacramento, and many other California cities. This is the single biggest time saver.

Hire an architect who knows your city. An architect who has permitted 20 ADUs in your specific city knows exactly what the plan checkers look for. They design to avoid corrections, not just to meet code. Ask how many ADU permits they’ve pulled in your jurisdiction in the last 12 months.

Get a site survey early. A licensed site survey eliminates setback disputes, boundary questions, and easement surprises that cause corrections during plan check.

Order the soil report before design. If your city requires a geotechnical report, get it before your structural engineer designs the foundation. Designing the foundation first and then discovering the soil doesn’t support it means redesign and resubmission.

Submit digitally. Every major California city now accepts online submissions. Digital submissions are processed faster, create a clear paper trail, and eliminate the back-and-forth of physical plan sets.

Respond to corrections immediately. When you receive a correction letter, your clock has stopped. Every day you delay revisions is a day added to your total timeline. Have your architect and engineer on standby during the review period.

SB 543 (effective 2025) gives homeowners new tools when cities don’t comply with ADU timelines:

• 15-day completeness determination: If the city doesn’t respond within 15 days of submission, the application is deemed complete by default — the 60-day clock starts automatically.
• Itemized deficiency lists: Cities can no longer issue vague rejection letters. They must provide specific, itemized lists of what needs to be corrected.
• Appeal rights: If your application is denied, SB 543 gives you the right to appeal to the California Department of Housing and Community Development (HCD). HCD has the authority to override local denials that violate state ADU law.
• Deemed approved: If the city fails to act within 60 days on a complete application, the application may be deemed approved under certain conditions. This is the nuclear option — it exists to prevent cities from blocking ADUs through inaction.

In practice, most delays are caused by plan check corrections, not by cities ignoring applications. The SB 543 protections are most useful when a city is slow to begin review or issues overly broad rejection letters without specific code citations.

For the full legislative breakdown, see our California ADU Law Explained (SB 543) guide.

How long does it take to get an ADU permit in California?

ADU permit timelines in California range from 2 weeks (pre-approved standard plans) to 16+ weeks (custom plans in Los Angeles with corrections). Sacramento and San Diego average 4 to 8 weeks. LA averages 8 to 16 weeks. The quality of your initial submission is the biggest factor.

Does California have a 60-day ADU permit approval rule?

Yes. California law requires cities to approve or deny a complete ADU application within 60 days. However, the clock pauses when corrections are issued and restarts when you resubmit. Most delays come from correction cycles, not from cities violating the 60-day rule.

How long does an ADU permit take in Los Angeles?

8 to 16 weeks for custom plans. 3 to 6 weeks for pre-approved Standard Plan designs. LADBS processes more ADU permits than any other city in the country, and the volume creates backlogs. Hillside properties and HPOZ zones add additional weeks.

How long does an ADU permit take in Sacramento?

4 to 8 weeks for custom plans, 2 to 4 weeks for standard plans. Sacramento is one of the faster ADU permitting jurisdictions in California with efficient online submission and responsive plan checkers.

How long does an ADU permit take in San Diego?

4 to 8 weeks for custom plans, 2 to 3 weeks for pre-approved designs. San Diego has the fastest ADU permitting among California’s major cities. Coastal Zone properties are the exception — add 2 to 6 months for Coastal Development Permit review.

Why is my ADU permit taking so long?

The most common reasons: incomplete structural calculations triggering corrections, Title 24 energy code non-compliance, setback violations, missing documents, sewer capacity issues, or additional agency reviews (fire department, Coastal Commission, HPOZ). Each correction cycle adds 2 to 4 weeks.

Can I speed up my ADU permit?

Yes. Use pre-approved standard plans, hire an architect with local ADU permitting experience, get a site survey before design, order soil reports early, submit digitally, and respond to corrections immediately. The fastest permits go to homeowners whose initial submissions have zero errors.

What happens if the city doesn’t approve my ADU permit in 60 days?

Under SB 543, you have appeal rights through the California Department of Housing and Community Development (HCD). If the city fails to act on a complete application within 60 days, the application may be deemed approved. In practice, contact HCD and cite the specific timeline violation.