Building an ADU in Los Angeles

What you can build in Los Angeles

ADUs are approved through a ministerial (no-hearing) process anywhere in the city that is zoned for single-family or multifamily homes, as long as there is an existing or proposed home on the lot. Junior ADUs (JADUs) are allowed in zones that permit single-family homes, on a lot with a single-family house.

Los Angeles runs two sets of rules side by side:

• State ADUs follow California law (Gov. Code 66323; see our California page). They must be approved if they meet state limits, and local zoning, design and development standards do not apply to them.
• Ordinance ADUs follow the city's own ADU ordinance (LAMC 12.22 A.33). They can be larger, but other city zoning rules apply.

On a single-family lot, state law lets you combine one ADU converted from existing space, one JADU and one new detached ADU of up to 800 sq ft. You can also pair a detached state ADU with an attached ordinance ADU, or an attached state ADU with a detached ordinance ADU, if each meets its standards.

On a lot with an existing apartment building, state law allows ADUs in non-living space (storage rooms, garages, basements and similar) for up to 25% of the existing units, with at least one. It also allows up to eight detached ADUs, but no more than the number of existing units.

The city cannot deny a state-law ADU because the lot is below the zone's minimum lot size. The city's 2019 ordinance predates several state laws; the current interpretation is in ZA Memo 143, Revision 1 (August 2025), which says it "shall be applied consistent with State law." [1][2]

Size, height and setbacks

Detached ADUs. A new detached state ADU can be up to 800 sq ft with 4-foot side and rear setbacks. Under the city ordinance, a detached ADU can be up to 1,200 sq ft. Lot floor-area limits (RFA in the R1, RE, RS and RA zones), front setbacks and lot coverage can shrink an ordinance ADU, but they cannot be used against a state ADU or to block an 800 sq ft unit. For example, a floor-area or HPOZ rule that would cap an ADU at 700 sq ft is overridden to allow 800 sq ft.

Attached ADUs. An attached ordinance ADU can be up to 50% of the existing home. Even if that is smaller, the city must allow an attached ADU of 850 sq ft, or 1,000 sq ft if it has more than one bedroom.

Height. A detached ADU can be 16 feet tall. Within a half-mile walk of a major transit stop or high-quality transit corridor it can be 18 feet, plus 2 more feet (20 feet total) if its roof pitch matches the main house. You can show transit distance with the SB 9 Eligibility viewer on ZIMAS.

Setbacks and location. New construction needs 4-foot side and rear setbacks. Converting an existing building, or rebuilding one in the same place and size, needs no added setback. A detached ordinance ADU generally must sit behind the main house, but front setbacks can't block an 800 sq ft ADU that won't fit anywhere else.

Hillside and fire zones. The city ordinance bars ADUs on lots that are in both a Very High Fire Hazard Severity Zone and a Hillside Area, with some exceptions. Per state housing agency guidance, that ban can't be applied to state-law ADUs. Confirm your lot's status with LADBS.

Coastal zone. State ADU law does not override the Coastal Act. ZA Memo 143 (August 2025) says the city's Coastal Development Permit process applies, with a discretionary filing and a public hearing. A 2025 state law change, per the state housing agency, requires a coastal permit for an ADU to be approved or denied within 60 days of a complete application, and says no public hearing is required where the local coastal program covers ADUs. Ask City Planning coastal staff at venicelcp@lacity.org which process applies to your lot. [1][2]

Parking

An ordinance ADU needs one parking space unless one of these applies:

• It is within a half-mile walk of a bus or rail stop.
• It is one block from a car-share pickup spot.
• It is in a historic district.
• It is fully inside an existing or proposed house or an existing accessory building.
• On-street parking permits are required but not offered to the ADU occupant.
• You apply for the ADU together with a new house or apartment building on the lot.

State-law ADUs and JADUs need no parking. If you tear down a garage, carport or parking space to build an ADU, you don't have to replace that parking. The Bureau of Engineering may require you to remove a driveway that no longer leads to parking. [1]

Fees

Impact fees. Since January 1, 2026, state law bars impact fees on an ADU with 750 sq ft of interior livable space or less, and fees on a larger ADU must be in proportion to the main home's size. LADBS's bulletin (revised August 2026) still words this as "750 sf or more," so if your ADU is close to 750 sq ft, confirm with LADBS. In Los Angeles these fees are the Residential Development Fee and the Dwelling Unit Construction Tax. The city may use county assessor records for the main home's size.

Exempt. ADUs and JADUs don't pay Park Fees or the Affordable Housing Linkage Fee.

School fees. LAUSD school fees apply to ADUs larger than 500 sq ft. Under state law, ADUs and JADUs under 500 sq ft of interior livable space are not subject to school impact fees.

Utility connection fees. Any water or sewer connection fee or capacity charge must be proportionate to the ADU's burden, based on its size or plumbing fixtures. A JADU is not a separate unit for water, sewer or power service, including connection fees.

Plan check and permit fees. LADBS bases these on the project's valuation (total cost of construction). You can get an estimate with the LADBS Permit Fee Calculator. For typical cost ranges, see our ADU cost guide and financing options. [1][2][3][4]

How long it takes

Since January 1, 2026, state law requires the city to tell you in writing within 15 business days whether your ADU application is complete, and to list anything missing. City departments, including LADBS, City Planning and LADWP, must then approve or deny an ADU application within 60 days of receiving a complete application, including payment of fees. A denial comes as written comments saying what to fix. If the city misses the 60 days, the application is deemed approved under state law.

If you apply for the ADU together with a new house or apartment building, the ADU permit can be held to issue with the other units, but the ADU can't be pulled into a hearing. Before a permit issues, other departments must sign off ("clearances"), such as a Bureau of Engineering sewer availability check and Fire Department hydrant and access review. See our ADU permit process guide for the general steps. [1][2][3]

Garage conversions and existing buildings

You can turn an existing garage or other accessory building into an ADU, and a state-law conversion can add up to 150 sq ft, only for entry and exit. No new setbacks are needed for the existing walls, and you don't have to replace the lost parking. If the garage was permitted, bring its Certificate of Occupancy and past permits to plan check.

LADBS's conversion bulletin sets the building rules. Walls less than 5 feet from the property line (3 feet if sprinklered) must be 1-hour fire rated. Sprinklers are needed only if the main house already has them or major remodeling triggers them. The ADU needs its own water shut-off valve and a separate electrical panel. A garage door opening can be filled in with 2x4 studs, and the existing header can stay.

If you are demolishing a detached garage to build an ADU, the city must review the demolition permit together with the ADU permit. More in our garage conversion guide.

Legalizing an unpermitted unit. Under AB 2533, the city can't deny a permit for an unpermitted ADU or JADU built before January 1, 2020 just because it breaks building or zoning rules, unless the unit is substandard or a fix is needed for health and safety. You may hire a third-party inspector first, but that doesn't replace LADBS permits and inspections. See IB P/BC 2026-150 and the streamlined bulletin on the LADBS ADU page. [1][3]

Junior ADUs

A JADU is up to 500 sq ft and fully inside a single-family home, including an attached garage. You can have one per lot. It needs its own outside entrance and at least an efficiency kitchen (a cooking facility with at least two appliances, a prep counter and storage). It can share a bathroom with the house; if it does, it needs an inside connection to the house.

Owner occupancy: the city's ZA Memo 143 (August 2025) says the owner must live in either the house or the JADU. A state law in effect January 1, 2026 narrowed this: the owner must live on site only if the JADU shares a bathroom with the house. The memo predates that change, so confirm with LADBS. A JADU can't be a short-term rental; if rented, the term must be longer than 30 days.

The city requires a deed restriction, approved by LADBS and recorded with the county recorder, before the JADU permit is issued. No parking is required. The Fire Department requires a separate address, which may mean separate trash fees. See our junior ADU guide. [1][2]

Lot splits and duplexes (SB 9)

SB 9 lets you build two homes on a single-family lot, or split the lot in two, if the lot meets the eligibility rules. Two-unit projects go to LADBS for plan check; lot splits are filed with City Planning. Check eligibility with the SB 9 Eligibility checklist in ZIMAS under "Planning and Zoning."

On a lot that has not been split, you can build an SB 9 duplex together with up to two detached state ADUs. Details are on the LADBS SB 9 page and in our SB 9 guide. [1][5]

Renting it out

You can rent an ADU, and the city cannot require you to live on the property (a JADU that shares a bathroom with the house is the exception). The city may require rentals of 30 days or longer. You can't sell the ADU separately from the main home, except under a narrow state-law exception for certain projects built by qualified nonprofits.

For short-term rentals (30 days or less), Los Angeles's Home-Sharing rules say an ADU whose permit application was submitted on or after January 1, 2017 can't be used for home-sharing unless it is the host's primary residence, meaning the host lives there more than six months of the year. Home-sharing is capped at 120 days a year without an extended registration. Read the Home-Sharing Administrative Guidelines. [1][2][6][7]

Permit steps in Los Angeles

1. Check your lot

   Look up your property in ZIMAS. Under "Planning and Zoning," its SB 9 Eligibility viewer shows transit distance, which can raise your height limit or waive parking. Confirm hillside, fire-zone and coastal limits with LADBS. [1][5]

2. Choose your ADU type and a design

   Decide between a state-law ADU (800 sq ft detached, fewer local rules) and an ordinance ADU (up to 1,200 sq ft detached). You can hire a designer or buy a design from the LADBS Standard Plan catalog, after checking with LADBS that it fits your lot. [1][4][8]

3. Prepare a complete plan set

   Plan check needs a complete set of plans; submittal requirements are in LADBS Information Bulletin P/GI 2026-008. For a conversion of a permitted building, include its Certificate of Occupancy and past permits. [3]

4. Submit for plan check

   Submit your plans to LADBS online through ePlanLA. The 60-day decision clock starts with a complete application and paid fees. [1][4]

5. Clear other departments

   Plan check will issue clearances, such as a Bureau of Engineering sewer availability check, Fire Department hydrant and access review, and LADWP review if you are near a utility easement. All must be signed off before the permit issues. [3]

6. Get your permit and build

   Once corrections and clearances are done, LADBS issues the permit. You or your contractor then request LADBS inspections as work proceeds. [3]

7. Final inspection and Certificate of Occupancy

   LADBS issues the Certificate of Occupancy after the final inspection and all clearances are approved. An ADU's certificate can't issue before the main home's. [3][6]

Pre-approved and sample plans

• LADBS Standard Plan Program

  Privately owned ADU designs pre-approved by LADBS for building, residential, green and energy codes; you buy the plan from its owner, and LADBS reviews it for your site's zoning and foundation before permitting. [4][10]

• Standard Plan catalog

  Searchable list of approved plans by type, stories and size, with the firm that owns each. [8]

Who to call

• Los Angeles Department of Building and Safety (LADBS)

  ADU plan check, permits and inspections; phone line refers zoning and code questions to engineers and inspectors

  3-1-1 in the city; (213) 473-3231 from outside

  [9][10]

• LADBS Metro Development Services Center

  Plan check, permits, inspection and case management (one of five service centers; others in Van Nuys, West LA, South LA and San Pedro)

  201 and 221 N. Figueroa St., Los Angeles, CA 90012

  [11]

• LA City Planning, Office of Zoning Administration

  ADU zoning interpretations (ZA Memo 143), SB 9 lot splits, coastal permits

  (213) 978-1318

  200 N. Spring Street, Room 763, Los Angeles, CA 90012

  [1]

Questions people ask