Once you submit, the city has 15 business days to decide whether the application is complete, then 60 days to approve or deny a complete application. If it misses that deadline, the application is deemed approved. Corrections, clearances from other departments, and plan revisions are what usually stretch the real timeline.
California sets firm deadlines for ADU permits, and they apply in Los Angeles. Knowing how the clock works, and what pauses it in practice, helps you plan the design and the budget.
The state clock
| Step | Deadline | Code |
|---|---|---|
| Completeness check | 15 business days; deemed complete if the city does not respond | Gov. Code 66317(a)(2)(A), (F) |
| Approve or deny | 60 days from a complete application; deemed approved if missed | Gov. Code 66317(a)(3) |
| Denial | Must list the deficient items and how to fix them | Gov. Code 66317(b) |
| Appeal of an incompleteness finding or denial | Written decision within 60 business days | Gov. Code 66317(d) |
How LADBS reviews an ADU
The Department of Building and Safety offers several paths: express permits for simple work, counter plan check, expanded counter plan check, and regular plan check for larger projects. Most ADUs go through plan check, submitted electronically through ePlanLA.
LADBS also runs a Standard Plan Program of pre-approved ADU designs, including a free city plan. A standard plan shortens the building code review, but the site-specific items, such as zoning, foundation, and soils, are still reviewed, and the permit and its fees still apply.
Other departments that can be involved
- Fire Department: an ADU more than 150 feet from the roadway, or a detached ADU in a High or Very High fire zone, gets hydrant and access review.
- Sanitation: sewer availability for a new unit.
- Urban Forestry: work within 15 feet of a protected native tree or a street tree.
- LADWP: work within 10 feet of power lines or an easement.
- City Planning: historic districts, coastal permits, and other overlays.
Each clearance is its own review, which is why a complete, well-coordinated submittal matters as much as the state deadline.
Deadlines after approval
A plan check stays open for 18 months from payment of the plan check fee, and LADBS can grant up to four 6-month extensions. Once issued, a building permit is valid for two years, but it expires if work does not start within 12 months or stops for 12 months. At the end, LADBS issues a Certificate of Occupancy for the new unit.
For the size and height rules that shape what you submit, see ADU rules in Los Angeles.
Look up your address on ZIMAS, the City of Los Angeles's free online parcel map. It shows your lot's zone and height district, and whether it sits in a specific plan, a historic district (HPOZ), or another overlay. Those details decide which of the rules above apply to your property.
Common questions
How long does the city have to approve an ADU permit?
60 days from a complete application, after a 15 business day completeness check. If the city misses the 60 day deadline, the application is deemed approved under Government Code 66317.
Do pre-approved ADU plans skip plan check in LA?
No. LADBS standard plans shorten the building code review, but zoning, foundation, and soils are still reviewed for your site, and the permit and fees still apply.
How long is an LA building permit good for?
Two years from issuance, but it expires if work does not start within 12 months, or if work stops for 12 months in a row.
Gov. Code 66317 | LADBS plan review and permitting | LADBS Standard Plan Program | LADBS Building Permit Clearance Handbook | LADBS plan check extension policy
Rules change and every lot is different. This guide is general information, not advice for your property; confirm the rules for your lot before you design or build.