Your drawings are finished, your contractor is ready, and the only thing left is the city. A neighbour says their permit took most of a year. Someone at the counter mentions a hearing. For a backyard unit in Los Angeles, neither of those should be true — and the law is unusually specific about why.
An accessory dwelling unit (ADU) permit in Los Angeles is decided by staff, without a hearing and without discretionary approval (§ 12.22 A.33(c)(2)). The city has 15 business days to tell you in writing whether your application is complete, and 60 days from a complete application to approve or deny it (§ 66317). If it misses the 60 days, your permit is deemed approved.
The clocks on your application
| Step | Deadline | Where it is written |
|---|---|---|
| City must tell you in writing whether your application is complete | 15 business days | § 66317(a)(2) |
| City must approve or deny | 60 days from a complete application | § 66317(a)(3), § 12.22 A.33(c)(2) |
| City misses the 60 days | Permit deemed approved | § 66317(a)(3) |
| Decision using a city-preapproved plan | 30 days | § 65852.27(b) |
| Written decision on an appeal | 60 business days | § 66317(d)(2) |
| Permit to demolish the garage you are replacing | Issued at the same time as the ADU permit | § 66314(e) |
What "ministerial" actually buys you
Ministerial means a public employee checks your plans against a written checklist and nothing else. State law defines the standards they may apply as objective standards — ones that "involve no personal or subjective judgment by a public official" and are verifiable against a benchmark both you and the reviewer can read before you submit (§ 66313(i)).
So the reviewer is not weighing whether your unit fits the neighbourhood's character. They are asking whether it meets the numbers already published. Los Angeles says the same thing in its own ordinance: a complying ADU "shall not require a discretionary planning approval," and review is "limited to only considering the project's compliance with the applicable objective standards" (§ 12.22 A.33(c)(2)).
One more piece of leverage: no other local rule can be used to hold the permit up. Nothing but an ADU ordinance consistent with state law "shall be the basis for the delay or denial of a building permit" (§ 66317(c)).
The completeness clock is the one people miss
Most permits stall in the gap before the 60-day clock even starts, because the 60 days runs from a complete application. State law closes that gap in four ways (§ 66317(a)(2)):
- The city has 15 business days to decide whether your submission is complete and to tell you in writing.
- If it is incomplete, that written notice must list every missing item and describe how to fix each one.
- When you resubmit, the city cannot ask you for an item that was not on that list.
- If the city blows the 15 business days, your application "shall be deemed to be complete."
Keep the written notice. It is the document that defines what the city is allowed to ask you for.
Note that the clock is not just the planning counter's. A "permitting agency" is any body whose review you cannot go around — planning, building and safety, utilities and special districts included (§ 66313(k)).
Then the 60 days, and what happens if they lapse
Once your application is complete, the city has 60 days. The consequence is the sharpest sentence in the statute:
If the local agency has not approved or denied the completed application within 60 days, the application shall be deemed approved.
Two practical caveats sit next to it (§ 66317(a)(3)). If you file the ADU alongside a permit for a new primary house on the lot, the city may wait for the house decision first. And if you ask for a delay, the 60 days is paused for as long as the delay lasts — so put any request for extra time in writing and know you are stopping your own clock.
What the city cannot make you fix first
A common way an ADU application dies is a reviewer attaching someone else's problem to it. State law forecloses several of those:
- Nonconforming zoning conditions — an existing feature that no longer meets current zoning — cannot be made a condition of ministerial approval (§ 66323(c)).
- The city cannot deny your application over nonconforming conditions, building code violations, or unpermitted structures that do not threaten health and safety and are not affected by the new unit (§ 66322(b)).
- Replacement parking cannot be required when a garage, carport or parking space is demolished or converted to make the ADU (§ 66314(d)(11); § 12.22 A.33(c)(12)).
- Fire sprinklers are not required in the ADU if they are not required in the main house (§ 66323(d); § 12.22 A.33(c)(10)).
If you are tearing down a detached garage to build the unit, the demolition permit is reviewed with the ADU application and issued at the same time — and no public notice or placard is required, unless the property is in an architecturally and historically significant historic district (§ 66314(e)–(f)).
The 30-day lane: preapproved plans
Every California city was required to run a preapproval program for ADU plans and to post the approved plans on its website (§ 65852.27). If your application uses a preapproved plan, the deadline drops from 60 days to 30.
The pack of law behind this article does not spell out every condition that qualifies an application for the 30-day path, so treat it as a question to ask the counter rather than a guarantee — but it is worth asking before you commission custom drawings.
If you are denied
A denial is not the end of the process, and it cannot be a one-line rejection. Within the same deadline, the city must return "a full set of comments" listing what is defective or deficient and describing how you can remedy it (§ 66317(b)). You then have a written appeal to the governing body or the planning commission, and the city owes you a final written determination within 60 business days (§ 66317(d)).
What this article does not cover
These are the procedural rules. They do not tell you whether your particular lot qualifies, and Los Angeles has one hard disqualifier worth checking before anything else: an ADU is barred outright on a lot that is in both a Very High Fire Hazard Severity Zone and a designated Hillside Area, unless it meets one of two exceptions (§ 12.22 A.33(c)(4)). Size, height and setback limits are separate from the timeline as well — the state floors a city cannot zone below are in § 66321, and Los Angeles's own numbers are in § 12.22 A.33. Permit fees, the city's online submittal mechanics, and electrical scope are outside this law entirely; ask Building and Safety.
The state procedure above was amended by SB 543 and took its current form on January 1, 2026 (§ 66317). For more on what Los Angeles allows on the ground, see our Los Angeles code overview.
Sources
- Government Code § 66317 — ADU permit processing, deadlines and appeals
- Government Code § 66313 — definitions, including "objective standards" and "permitting agency"
- Government Code § 66314 — what a local ADU ordinance must contain
- Government Code § 66321 — size and height limits a city may not go below
- Government Code § 66322 — parking exemptions and nonconforming conditions
- Government Code § 66323 — units a city must approve ministerially
- Government Code § 65852.27 — preapproved ADU plans and the 30-day decision
- Los Angeles Municipal Code § 12.22 A.33(c) — ADU development standards and ministerial review
- Los Angeles Municipal Code § 12.22 A.33 — ADU and junior ADU applicability
