How long a detached ADU permit takes in Los Angeles in 2026: each LADBS step, what speeds it up, what slows it down, and state review deadlines explained.
For a detached ADU in the City of Los Angeles, plan on several months from the first design meeting to an issued permit: site research and design, then LADBS plan check, clearances from other city departments, and usually a round or two of corrections. Using an LADBS pre-approved standard plan typically shortens review, while hillside lots, long sewer runs, protected trees and difficult fire access lengthen it. State law requires the city to act on a complete ADU application within 60 days, but that clock starts only once the application is complete.
The detached ADU permit process, step by step
StageWhat happensWho is involvedWhat slows it down1. Site researchZoning, overlays, setbacks, utilities and access checkedContractor, designer; LA City Planning's ZIMAS mapHillside, historic or fire-zone overlays2. Survey and designSite plan, floor plan, structural and Title 24 energy calculationsDesigner, engineer, energy consultantCustom design, soils report on slopes3. Plan check submittalPlans submitted to LADBS for reviewLADBSIncomplete submittal packages4. Department clearancesOther departments sign off on items that apply to the lotMay include LAFD, LA Sanitation, LADWP, Urban Forestry, LA City PlanningFire access, sewer capacity, trees5. CorrectionsPlan checker comments answered and plans resubmittedDesigner, engineer, LADBSSlow responses, multiple rounds6. Permit issuanceFees paid, permit issuedLADBS, school districtOutstanding clearances or fees7. Construction inspectionsInspections at foundation, framing, rough trades, insulation and finalLADBS inspector, contractorFailed inspections, scheduling8. Final sign-offFinal inspection and Certificate of Occupancy for the new unitLADBSPunch items, missing documentation
In our experience, the review portion runs noticeably shorter with a standard plan than with a custom design; our ADU rules guide gives the typical approval windows we see. Your lot, not the calendar, decides where you fall.
What state law requires of the city
California's ADU laws, summarized in the California HCD ADU Handbook, require local agencies to approve or deny a complete ADU permit application ministerially within 60 days. That means no public hearing and no discretionary design review for a unit that meets the objective standards. If the application is denied, the city has to explain what is missing or noncompliant. Two practical limits: the clock applies to a complete application, and time spent preparing correction responses is on the applicant's side.
State ADU law has been amended in nearly every recent legislative session, with changes aimed at tightening review timelines, limiting what cities can require and making it easier to legalize older unpermitted units. We check the current HCD ADU Handbook and LADBS guidance at the start of every project rather than relying on last year's rules.
The standard plan shortcut
LADBS runs a Standard Plan Program with detached ADU designs that have already been reviewed for building code compliance. When you use one, plan check focuses on site-specific items: placement, setbacks, utilities, foundation for your soil and fire access. That typically saves design time and review time. The trade-off is flexibility: the unit has to fit your lot as designed, with limited changes. We use standard plans when the lot allows and custom plans when access, slope or lot shape call for them.
What slows a detached ADU permit down
- Hillside designation, which can require a soils report and additional review.
- Fire department access, especially when the unit sits far back from the street.
- Sewer capacity or a sewer route that crosses difficult ground.
- Protected trees or street trees near the construction area or driveway.
- Historic preservation overlay zones or specific plan areas.
- Incomplete submittals and slow responses to plan check corrections.
What speeds it up
- A current survey and a clear site plan showing utilities and trees.
- Choosing a standard plan when the lot fits one.
- Checking panel capacity and the sewer route before design is final.
- Answering correction comments completely in one round.
- Making finish selections early so construction can start right after permit issuance.
Garage conversions follow a different, usually shorter path because the structure already exists; that route is covered in our garage conversion permit guide.
After the permit: construction and inspections
Once the permit is issued, the build runs through a series of LADBS inspections: foundation before the pour, framing, rough plumbing, electrical and mechanical, insulation, drywall where required, and final. Each one has to pass before work covers it. On jobs like this we schedule inspections as each phase wraps so the crew is not waiting. The ADU is ready to occupy once it passes final inspection and LADBS signs off. We build detached ADUs across the Valley, including Sherman Oaks and Granada Hills, and we manage the permit process from design through final. Request a free written estimate and we will map out the permit path for your lot.
Frequently asked questions
How long does it take to get a detached ADU permit in Los Angeles?
Plan on several months from first design meeting to issued permit, with design and plan check making up most of that. A pre-approved standard plan on a simple, flat lot moves fastest. Custom designs, hillside lots, long sewer runs, protected trees and fire access issues add time. Answering plan check corrections completely in one round is the biggest thing you control. We give each client a written permit timeline after the site visit.
Does the city have to approve my ADU within 60 days?
Under California ADU law, summarized in the California HCD ADU Handbook, the city must approve or deny a complete ADU application within 60 days, without a public hearing. The clock runs from a complete application, not from your first submittal, and time spent preparing correction responses is on your side. If the city denies the application, it must explain what is missing or noncompliant.
What is the LADBS standard plan program for ADUs?
It is an LADBS program offering detached ADU designs that have already been reviewed for building code compliance. Using one means plan check focuses on how the unit fits your specific lot: placement, setbacks, utilities, foundation and fire access. It typically saves design and review time. The trade-off is less flexibility, since changes to the approved design are limited.
Which city departments review a detached ADU?
LADBS runs plan check and inspections. Depending on the lot, other departments may need to clear the project, such as the Los Angeles Fire Department for fire access, LA Sanitation for sewer capacity, LADWP for electrical service, Urban Forestry for street trees, and LA City Planning for overlays or specific plans. We identify which ones apply during site research so they do not surprise you at plan check.
Can I start construction before the permit is issued?
No. Construction on a detached ADU cannot start until LADBS issues the permit, and every stage has to pass inspection before it is covered. Starting early risks stop-work orders, tearing out finished work and trouble with the Certificate of Occupancy. What you can do while waiting is finalize selections, order long-lead items and schedule the crew so work starts right after issuance.