How to Get an ADU Permit in Los Angeles, Step by Step

An ADU permit in Los Angeles starts with a question most owners skip: which agency handles your address? Once that is settled, the path runs through plan check, clearances, inspections and a certificate of occupancy.

This guide follows that path in order, with the state deadlines that keep it moving.

Step 1: Confirm Who Issues Your ADU Permit

Los Angeles is two permit systems that share a name. Addresses inside the City of Los Angeles, including the San Fernando Valley neighborhoods from Tarzana to Sherman Oaks, are permitted by the Los Angeles Department of Building and Safety, or LADBS.

Unincorporated communities are not in the city. Altadena, for example, is unincorporated, so an ADU there goes through Los Angeles County Public Works, which runs its own pre-approved plan program.

Cities such as Calabasas and Glendale run their own building departments too. A mailing address that says “Los Angeles” does not settle the question, so check the city’s ZIMAS zoning map, which only covers parcels inside the city.

Step 2: Check What Your Lot Allows

Before anyone draws plans, confirm the zoning, size limits and setbacks for your parcel. Our guide to Los Angeles ADU requirements covers the size and setback rules in detail.

Two map layers matter most on hillside lots: the Hillside Area and the Very High Fire Hazard Severity Zone. LAMC 12.22 A.33(c)(4) restricts ADUs on lots that sit in both a Hillside Area and a Very High Fire Hazard Severity Zone. City Planning’s current guidance, ZA Memo 143, says that restriction is not enforced on state-law ADU types, which include garage conversions, junior ADUs and detached units up to 800 square feet.

Larger ADUs built under the city’s own rules still face the restriction. The city no longer enforces its sprinkler and parking conditions where they conflict with state law, but a street dedication can still be required. California’s housing department also wrote to the city in November 2024 that the prohibition conflicts with state ADU law, so pick the ADU type with these rules in mind.

A design-build team that handles the ADU permit in Los Angeles from first survey to final inspection will run these checks at the start, when changes cost the least.

Step 3: Prepare the Plans

An ADU permit set usually includes architectural plans, structural drawings and calculations, and Title 24 energy compliance forms. Hillside lots often add a survey, a soils report and grading plans.

Consider a standard plan

LADBS runs a Standard Plan Program for ADU designs that are built over and over. The department says using standard plans “shortens the time needed to review the plans through plan check,” so permits are issued sooner.

A standard plan still gets a site-specific review for zoning and the foundation. California required every local agency to offer a pre-approval program by January 1, 2025.

Step 4: Submit Through ePlanLA

LADBS accepts permit applications and documents online through ePlanLA, or in person by appointment at its offices. For most San Fernando Valley addresses, the Van Nuys office is the closest in-person option.

State law sets two clocks from here:

• Completeness: if the city does not tell you within 15 business days that the application is incomplete, it is deemed complete.
• Decision: the city must approve or deny a complete ADU application within 60 days. If it misses that deadline, the application is deemed approved.

If the city denies the application, it must give a full list of the problems and how to fix them. A new submittal starts a new 60-day period.

Step 5: Plan Check, Corrections and Clearances

During plan check, LADBS reviews the plans against the building and zoning codes and issues corrections. Clearances from other departments are generated during plan check and must be approved before the permit issues. A 2026 LADBS bulletin lists these:

An LADBS ADU correction sheet warns that some department reviews can take months, and notes that a plan check expires 18 months after submittal. Answering corrections quickly is the single biggest thing an owner can do to keep the timeline short.

Step 6: Pay Fees and Pull the Permit

Once corrections are cleared, clearances are approved and fees are paid, LADBS issues the permit. Plan check and permit fees are based on the project’s valuation.

State law also controls impact and school fees. ADUs of 750 square feet or less pay no impact fees, and units under 500 square feet pay no school fees. The size of the unit drives most of the cost, as our guide to ADU construction cost by size shows.

Step 7: Inspections and the Certificate of Occupancy

After the permit issues, construction moves through a series of inspections: foundation, framing, rough plumbing, electrical and mechanical, insulation, drywall and final.

California law requires a certificate of occupancy before anyone lives in an ADU. That document is what makes the unit legal to rent, and buyers and lenders will ask for it later.

LADBS posts current ADU guidance, standard plan details and forms on its ADU page.

Owner Occupancy and Junior ADUs

State law no longer allows cities to require that the owner live on a property with an ADU. AB 976, passed in 2023, made that rule permanent.

Junior ADUs are the exception. A junior ADU that shares a bathroom with the main house still requires the owner to live on the property.

Frequently Asked Questions

How much does it cost to get an ADU permit in Los Angeles?

The cost to get an ADU permit in Los Angeles depends on the project’s valuation, because LADBS bases plan check and permit fees on it rather than on a flat ADU rate. Size also matters for other fees.

An ADU of 750 square feet or less pays no impact fees, and a unit under 500 square feet pays no school fees. Design, engineering and Title 24 reports are separate from city fees.

What happens if you build an ADU without a permit in California?

Building an ADU without a permit in California means the unit cannot be legally rented, and it can cause trouble with insurance, refinancing and resale. The city can also cite the owner and require changes or removal. A 2024 state law, AB 2533, created a path to legalize many older unpermitted units, and LADBS published its process for those cases in July 2026.

Can I build 2 ADUs on my property in California?

Yes, many California properties can have two ADUs, depending on the lot and the main house. In the City of Los Angeles, City Planning’s ZA Memo 143 lists the combinations by lot type.

On a single-family lot, a common pairing is one detached ADU plus one junior ADU carved from the main house. Multifamily lots can add more units. Check the combination before design, because it decides which permit path each unit takes.

What are the common mistakes when building an ADU?

The common mistakes when building an ADU start in permitting. Owners design before checking hillside and fire zone maps, size the unit just over a fee threshold, or skip the sewer and electrical capacity check.

During plan check, slow answers to corrections stall the project. Moving into the unit before the certificate of occupancy issues is another mistake that can cause problems at resale.

Getting Your ADU Permit Started

Most delays in an ADU permit come from the start of the project: the wrong agency, a hillside rule found late, or plans drawn before the lot was checked. Settle those first and the state’s 60-day clock works in your favor.

A local design-build team can check your lot, prepare the plan set and manage corrections through final. Request a free estimate to begin.