How long an ADU permit takes: the clock the statute gives you
PUBLISHED SEPTEMBER 10, 2026 · UPDATED SEPTEMBER 10, 2026 · REVIEWED BY MILAD KAZEMI
California gives you two enforceable deadlines rather than an estimate. Under Government Code § 66317(a)(2), the permitting agency has 15 business days from receipt to determine whether your ADU application is complete and tell you in writing; if it does not, the application is deemed complete. Under § 66317(a)(3), it then has 60 days from a complete application to approve or deny, and if it does neither the application is deemed approved. The clock tolls only if you request a delay, or if you filed alongside an application for a new primary dwelling. Junior ADUs are treated differently: § 66335 imposes the same 15-business-day and 60-day duties but contains no deemed-approved provision.
Law verified as of 10 September 2026 against the text published by the California Legislature. Sections 66317 and 66335 were both amended by SB 543, Stats. 2025, ch. 520, effective 1 January 2026.
Why every timeline you have read is unsourced
Search for how long an ADU permit takes in Los Angeles and you get numbers — six weeks, three months, six months — with nothing behind them. They are recollections of individual projects, and they vary because the underlying projects varied.
There is a timeline that is actually binding, and it is in the statute. It is worth knowing precisely, because it is the only part of the process anyone can hold an agency to.
The two clocks
| Stage | Deadline | If the agency misses it | Statute |
|---|---|---|---|
| Completeness determination, in writing | 15 business days from receipt | Application is deemed complete | § 66317(a)(2)(A), (F) |
| Decision to approve or deny | 60 days from a complete application | Application is deemed approved | § 66317(a)(3) |
| Written comments on a denial | Within the same 60 days | Denial does not comply | § 66317(b) |
| Final determination on appeal | 60 business days from your written appeal | — | § 66317(d)(2) |
The 60 days runs from receipt of a completed application, not from your first submittal. That is the single most important mechanical detail, and it is why the completeness stage deserves more attention than it usually gets.
The correction-list rule is the useful one
Section 66317(a)(2) does more than set a deadline. It constrains what the agency may do with an incomplete application.
If the agency finds your application incomplete, it must give you — with the written notice, inside the 15 business days — a list of the incomplete items and a description of how to make the application complete. Then, under § 66317(a)(2)(D), when it reviews what you resubmit, it shall not require the application to include an item that was not included in that list.
That closes the loop that otherwise costs projects months: the sequential correction cycle, where each resubmittal surfaces a requirement nobody mentioned last time. The statute allows one list.
What tolling actually covers
Two things, and only two, appear in § 66317(a)(3):
- A delay you request. The 60-day period is tolled for the period of that delay.
- A concurrent new primary dwelling. If the ADU application is filed with an application to create a new single-family or multifamily dwelling on the lot, the agency may hold the ADU decision until it decides the primary dwelling — but the ADU is still considered without discretionary review or a hearing.
Time you spend responding to a correction list is your own time, not agency time, and it sits outside the clock in the sense that the agency is not running down its 60 days while it waits for you. Which is another way of saying the fastest thing you control is the quality of the first submittal.
The junior ADU gap
Section 66335 mirrors § 66317 closely for junior ADUs. Same 15 business days to determine completeness. Same deemed-complete consequence at § 66335(a)(2)(F). Same 60-day duty to approve or deny at § 66335(a)(3). Same requirement to return a full set of written comments on a denial. Same 60 business days on appeal.
One thing is missing. Section 66317(a)(3) ends with the sentence that if the agency has not approved or denied within 60 days, “the application shall be deemed approved.” Section 66335 has no equivalent.
So a JADU applicant has the deadline without the automatic remedy. In practice this rarely matters, because most JADU applications are straightforward and most agencies decide them. But if you are choosing between an ADU and a JADU and timing is a real constraint, it is a genuine asymmetry — and it is not mentioned anywhere in the popular guides. See JADU vs ADU for the rest of that comparison.
What the statute does not cover
Being honest about the boundary is more useful than a number.
The clock covers the permitting agency’s review. It does not cover the time to design and document the project before submittal, your own turnaround on a correction list, utility and fire clearances that run on their own schedules, or construction. Section 66313(k) defines a permitting agency broadly — including planning departments, building departments, utilities and special districts, “for which there is no substitute” — which helps, but it does not turn a whole project into a 60-day exercise.
The realistic way to compress a schedule is not to find a faster agency. It is to submit a set that survives the first review, and to know before you submit which of the § 66323 protected categories your project falls into — because a conversion of existing space is governed differently from new detached construction, and that classification changes what can be asked of you at all.
Sources
Rules change. Confirm anything you are relying on against the agency directly.
Questions we get asked
- How long does a city have to approve an ADU permit in California?
- Sixty days from a complete application, where there is an existing single-family or multifamily dwelling on the lot. Government Code § 66317(a)(3) requires the agency to approve or deny within that period, and provides that if it has not done so, the application is deemed approved.
- When does the 60-day clock start?
- From the date the agency receives a completed application — not from the date you first submitted. That is why the completeness stage matters: § 66317(a)(2)(A) gives the agency 15 business days to determine completeness and give you written notice, and § 66317(a)(2)(F) deems the application complete if it misses that.
- Can the city keep asking for more documents to restart the clock?
- Not for items it failed to list. Section 66317(a)(2)(B) requires the incompleteness notice to include a list of the incomplete items and how to cure them, and § 66317(a)(2)(D) bars the agency from requiring an item that was not on that list when it reviews your resubmittal.
- What does deemed approved actually mean in practice?
- That the statute treats the application as approved by operation of law when the agency lets the 60 days pass without approving or denying. It is a legal position rather than a permit card in your hand, and asserting it is a conversation with the agency. Its practical value is mostly that it makes the deadline real, which changes how applications get handled.
- Does the clock ever pause?
- Only in the ways the section names. Section 66317(a)(3) tolls the 60 days for the length of any delay you request. Where the ADU application is filed together with an application for a new single-family or multifamily dwelling, the agency may hold the ADU decision until it decides the primary dwelling.
- Do junior ADUs get the same protection?
- Not quite, and this is worth knowing. Section 66335 gives junior ADUs the same 15-business-day completeness rule, including deemed complete, and the same 60-day duty to approve or deny. But unlike § 66317(a)(3), § 66335 contains no provision deeming the application approved if the agency misses the 60 days. The deadline exists; the automatic remedy does not.
- What if the city denies it?
- A denial must be specific. Sections 66317(b) and 66335(b) both require the agency to return, within the same time period, a full set of written comments listing what is defective or deficient and describing how you can remedy it. A denial without that list does not comply.
- How long does an appeal take?
- Sixty business days for a final written determination, under §§ 66317(d)(2) and 66335(e)(2). Being permitted to appeal to both the planning commission and the governing body does not extend that period.
- So how long will my ADU actually take start to finish?
- The statutory clock is the only part anyone can promise you. Design and documentation before submittal, your own response time to a correction list, utility and fire clearances that run on their own schedules, and construction are all outside § 66317. Anyone quoting you a single number for the whole process is describing their last project, not yours.
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