Getting an ADU permit is mostly a paperwork process, with a few site-specific surprises. This guide covers the steps in the City of Los Angeles, and notes where other places differ.
LA ADU Guide is an information site. We do not prepare plans or pull permits. Confirm every step with your building department.
First, find out who permits your lot
Your mailing address city may not be the permitting agency.
- City of Los Angeles: the Department of Building and Safety (LADBS).
- Unincorporated LA County: LA County Public Works, Building and Safety, plus County Planning for zoning.
- Other cities (Long Beach, Pasadena, Santa Monica and many more) run their own departments.
The rest of this page describes the LADBS path. Other agencies follow the same state law but use their own forms and portals.
The state law behind it
California's ADU law is Government Code sections 66310 to 66342. It was renumbered in 2024 (SB 477, effective March 25, 2024) from the former section 65852.2. In general, a city must review qualifying ADUs through a ministerial process, which means a check against fixed standards, with no public hearing. For the rules on size, setbacks and parking, see ADU rules in California.
Step by step in the City of Los Angeles
LADBS says building plan check, permit issuance and inspections are required for ADUs and JADUs. The usual order:
- Check eligibility. Look at your zoning, overlays (hillside, coastal, historic), easements and fire zone. See ADUs in fire hazard zones.
- Get plans. Plans are drawn by a licensed designer, architect or engineer. You can also adapt a pre-approved design. See prefab and pre-approved plans.
- Submit electronically. LADBS uses a portal called ePlanLA. It says it is accepting ePlan submittals for all ADU projects: new, addition and alteration.
- Plan check. Staff review the plans for building code and zoning compliance. LADBS also reviews site factors like foundation requirements.
- Corrections. It is common to get a list of corrections. You revise and resubmit. LADBS says the permit is issued "once compliance with the listed corrections is verified."
- Pay fees and get the permit. Permit and plan check fees are based on project valuation. Utility and impact fees are separate. See impact fees and utility connections.
- Build and inspect. Inspections happen at stages. If you change the work, LADBS says construction that varies from the approved plans must return to plan check.
- Final inspection and Certificate of Occupancy. Schedule the final inspection before anyone moves in.
Who does what at each step
| Step | Who acts | What happens |
|---|---|---|
| 1. Eligibility | You | Check zoning, overlays, easements and fire zone |
| 2. Plans | Designer, architect or engineer | Draw plans, or adapt a pre-approved design |
| 3. Submit | You or your contractor | File through ePlanLA |
| 4. Plan check | LADBS | Review for building code and zoning compliance |
| 5. Corrections | Designer and LADBS | Revise and resubmit until the corrections are verified |
| 6. Permit | LADBS | Issued after fees are paid; fees are based on valuation |
| 7. Inspections | LADBS | Staged inspections; changes return to plan check |
| 8. Final | LADBS | Final inspection and Certificate of Occupancy before move-in |
Time limits: 60 days for the agency to act on a complete application (section 66317), and the LADBS application expires 18 months from plan check submittal. LADBS publishes no single timeline for the steps in between.
The deadlines state law sets
State law puts time limits on the city. Under Government Code section 66317, a local agency must act on a complete ADU application within 60 days. Secondary summaries say that missing the deadline means the application is deemed approved, but HCD has noted the statute itself says "approve or deny," so do not treat deemed approval as automatic without legal advice.
Recent change: SB 543 took effect January 1, 2026. Per a legal aid summary, it requires a completeness review within 15 business days, with deemed-complete and deemed-approved consequences if the agency misses its deadlines. The ABAG summary also lists a shorter clock for detached ADUs using a pre-approved plan. We could not confirm the exact text of these provisions, so check section 66317 directly.
Two practical notes:
- The clock starts on a complete application. Missing documents mean it has not started.
- If you ask for a delay, the 60 days is paused for that period, per HCD letters to cities.
Zoning review
Zoning review happens inside plan check at LADBS. Depending on your lot, you may also need outside sign-offs, such as the Fire Department, a soils or structural review, a coastal zone review or a historic district review. A third-party source says these can stretch a project to about nine months. Treat that as an anecdote, not a guarantee.
What the application usually needs
Requirements vary by project, so ask LADBS for its current checklist. Typical items include:
- Site plan showing the lot, existing buildings, setbacks and the new ADU.
- Floor plans, elevations and structural details.
- Energy and green building documents.
- Proof of ownership and the application form.
- Soils or geotechnical information if your lot needs it.
Timeline and cost
We do not give a single timeline, because published numbers come from consultants, not LADBS. LADBS itself says the application expires 18 months from the plan check submittal date. For costs, see ADU cost in Los Angeles.
If you live outside the City of Los Angeles
The state deadlines and ministerial standards apply everywhere in California, but the forms, fees and portals do not. LA County Public Works handles unincorporated areas, and each other city has its own counter and checklist. Start by finding the right office for your parcel, then ask for that office's ADU handout. Fire zone rules can differ depending on who permits the home, so confirm that early. A plan that was approved in one city is not automatically accepted in another, even for the same design.
Who does what
- You, the owner: sign the application, pay fees, and keep records.
- Designer or engineer: prepares the plans and answers corrections.
- Licensed contractor: builds the unit and usually pulls the permit. See hiring an ADU builder.
- Building department: reviews, issues the permit, and inspects.
Keep a folder, paper or digital, with the application, correction letters, approved plans, inspection cards and receipts. It helps if a question comes up at final inspection or when you later sell.
Checklist
- Confirm who permits your lot.
- Check zoning, overlays and fire zone first.
- Use a licensed professional for plans.
- Submit through ePlanLA and track it there.
- Respond to corrections quickly and completely.
- Keep the stamped plans on site.
- Request each inspection before covering work.
- Get the final sign-off before occupancy.
Common mistakes
- Starting work before the permit is issued.
- Changing the design mid-build without telling the city.
- Paying a contractor for "permits" up front. CSLB warns you to confirm permit costs with your building department.
- Assuming a pre-approved plan removes site review.
For general LADBS questions, use the department's main line or 311.