ADU Rules in Los Angeles (2026): What You Can Build

An accessory dwelling unit (ADU) is a second, self-contained home on the same lot as your house, with its own kitchen, bathroom and entrance. The City of Los Angeles permits ADUs under California ADU law (Government Code sections 66310–66342) and its own ordinance, Los Angeles Municipal Code 12.22 A.33, which together allow a detached ADU of up to 1,200 square feet on most residential lots and guarantee at least an 800-square-foot unit with four-foot side and rear setbacks on nearly any lot with a house. Green Design and Build is a licensed general contractor (CSLB #1110975) based in Van Nuys, serving homeowners across Los Angeles County, Orange County, Ventura County, western Riverside County and western San Bernardino County. This page covers the City of Los Angeles only, every neighborhood permitted by the Los Angeles Department of Building and Safety (LADBS) from the San Fernando Valley to San Pedro; other cities are on the ADU rules hub.

Who we are

Green Design and Build is led by Dekel Sofer. We hold a 4.7-star rating across 146 Yelp reviews and have completed hundreds of projects. We are a full-service residential general contractor and design-build remodeler, not an ADU specialist: we build ADUs and garage conversions alongside kitchens, bathrooms, additions and whole-home renovations.

ADU rules in Los Angeles at a glance

Size, height and setbacks

Los Angeles runs two tracks side by side. A state-law ADU (Government Code 66323) is the unit the city must approve on any lot with a house: detached, up to 800 square feet and 16 feet tall, with four-foot side and rear setbacks. Local limits, including Residential Floor Area under the Baseline Hillside and Mansionization ordinances, cannot block it, and it is exempt from the city’s design standards. An ordinance ADU (LAMC 12.22 A.33) is the larger unit most homeowners want: detached up to 1,200 square feet and two stories within the zone’s height limit, or attached up to half the house’s floor area, checked against the zone’s height, floor-area ratio and lot coverage, and generally placed behind the main house.

The local twists that change the answer for a specific address:

• Hillside Areas and Very High Fire Hazard Severity Zones. The ordinance prohibits an ADU on a lot in both a designated Hillside Area and a Very High Fire Hazard Severity Zone unless it meets one of the ordinance’s limited exceptions. It cannot be applied to a state-law ADU, so an 800-square-foot unit remains possible in the Hollywood Hills or Bel Air, with fire sprinklers, Chapter 7A construction and usually a geotechnical report.
• HPOZ historic districts. No parking is required, but a garage demolition needs the notice the city otherwise waives for ADUs, and street-visible work goes through the HPOZ’s exterior review.
• Coastal Zone. In Venice, Playa del Rey, Pacific Palisades and parts of San Pedro a Coastal Development Permit may be required, and that process, not the 60-day ADU clock, sets the timeline.
• Transit. Within half a mile of a major transit stop a state-law detached ADU can be 18 feet, and near any public transit no ADU parking can be required.

The California ADU rules calculator runs these questions for your lot.

Garage conversions and JADUs in Los Angeles

A garage conversion is the most common ADU in Los Angeles because post-war lots came with a detached two-car garage at the back. The city must approve the conversion of an existing accessory structure with no new setback, even on the property line, with an expansion of up to 150 square feet solely for entry and exit, and no replacement parking. A garage with no footing or a failing slab can be demolished and rebuilt in the same location and dimensions, still with no setback. Fire sprinklers follow the main house: if it was not required to have them, the ADU is not either, except for Hillside Area and fire-zone ordinance ADUs. Our post on why ADU quotes vary so much between contractors retells a garage conversion whose price rose roughly 40 percent once the slab, panel and sewer line were opened up.

A junior ADU is up to 500 square feet carved out of the existing house, with its own entrance and an efficiency kitchen; it may share a bathroom with the house. A deed restriction is recorded before the permit issues; since January 2026 state law requires the owner to live in the house or the JADU only when the JADU shares a bathroom with the house (Gov. Code 66333). It needs no new foundation, pays no impact fees and can sit alongside a detached ADU on the same lot.

Pre-approved plans, fees and utilities

Standard plans. Under the LADBS ADU Standard Plan Program, private architects submit designs that LADBS pre-approves for the building, residential and green codes; the city also owns one plan, the YOU-ADU, a one-bedroom of 455 square feet that any property owner may use free of charge. A standard plan removes the structural plan check, but LADBS still reviews zoning and foundation design for your lot, and valuation-based permit fees are unchanged. Our guide to the Los Angeles pre-approved ADU standard plans explains the catalog, including which plans have expired.

Fee categories. Expect LADBS plan check and building permit fees (valuation-based), electrical, plumbing and mechanical permit fees, City Planning clearance fees where applicable, and school district developer fees, which districts may charge on an ADU larger than 500 square feet. Impact fees are exempt at 750 square feet or less. LADBS sets amounts by schedule, so we do not publish them.

Utilities. An ADU converted from existing space cannot be required to have a new or separate utility connection or pay a connection fee or capacity charge as a new residence. A new-construction ADU may be connected separately, with any fee proportionate to its square footage or drainage fixture units. In practice a detached ADU usually shares the house’s LADWP service and sewer lateral, which is why an old sewer line and a 100-amp panel matter to the budget. New detached ADUs must also have solar panels under the state energy code.

The permit process in Los Angeles, step by step

1. Confirm the lot. Pull the zoning, Hillside Area, fire-zone, HPOZ and Coastal Zone flags from ZIMAS, the city’s zoning map, and confirm transit distance; this decides whether you build a state-law ADU, an ordinance ADU or both.
2. Design and engineering. Site plan, floor plans, elevations, structural calculations, Title 24 energy compliance and, on hillside lots, a soils report.
3. Submit to LADBS through ePlanLA. LADBS has 15 business days to say whether the submittal is complete.
4. Plan check and clearances. LADBS plan check runs alongside City Planning, Fire Department, LADWP or Sanitation clearances; every department must approve or deny a complete application within 60 days.
5. Permit issuance. Permits issue once fees are paid and any JADU deed restriction is recorded.
6. Construction and inspections. Foundation, framing, rough trades, insulation, drywall, lath and final, scheduled with the LADBS inspection district for your address.
7. Certificate of Occupancy. Issued by LADBS after the final inspection.

From first meeting to Certificate of Occupancy, plan on six months to a year; the 60-day clock covers plan review only.

What an ADU costs in Los Angeles

Our published Los Angeles figures, which are budgeting ranges rather than quotes: a garage conversion ADU runs $100,000–$200,000; a detached 500 sq ft ADU $180,000–$260,000; a 700–800 sq ft unit $225,000–$350,000; and a 1,000 sq ft unit $300,000–$450,000 or more. The rule of thumb is $300–$450 per square foot all-in, and $500 or more on difficult lots. In the City of Los Angeles those are hillside lots, where a geotechnical report, engineered footings and fire-zone construction push the cost up, and Coastal Zone properties, where the Coastal Development Permit adds months. On older flatland lots the sewer lateral and the electrical panel most often move a budget after demolition; our post on how much it costs to build an ADU walks through a real 600 sq ft detached ADU whose budget rose from $180,000 to $265,000 for exactly those reasons.

Frequently asked questions

What is the maximum ADU size allowed in Los Angeles?

The City of Los Angeles allows a detached ADU of up to 1,200 square feet under its ordinance, and an attached ADU of up to 50 percent of the house’s floor area, with a floor of 850 square feet (1,000 for more than one bedroom). Separately, state law guarantees a detached ADU of up to 800 square feet with four-foot setbacks on any Los Angeles lot with a house.

How tall can an ADU be in Los Angeles?

A state-law detached ADU in Los Angeles can be 16 feet tall, or 18 feet within half a mile of a major transit stop, plus 2 feet to match the main roof pitch. An ordinance ADU can go to the zone’s height limit and two stories if detached, or up to 25 feet or the zone limit, whichever is lower, if attached.

Do I need to provide parking for an ADU in Los Angeles?

No parking can be required for a state-law ADU in Los Angeles, and an ordinance ADU is exempt from its one-space requirement if the lot is within half a mile of public transit or one block of a car-share vehicle, inside a historic district, or the unit is within an existing structure. When a garage is converted or demolished for an ADU, the lost parking need not be replaced.

Do I have to live on the property to build an ADU in Los Angeles?

No, the City of Los Angeles cannot require owner-occupancy for an ADU; state law suspended that authority in 2020 and AB 976 removed it permanently. A junior ADU is the exception only when it shares a bathroom with the main house: then the owner must live in the main house or the JADU. A JADU with its own bathroom has no owner-occupancy requirement (Gov. Code 66333); every JADU still records a deed restriction before the permit issues.

How long does LADBS take to approve an ADU?

Once LADBS receives a complete ADU application, it and every other city department involved must approve or deny it within 60 days, after 15 business days to confirm completeness; a missed deadline means the application is deemed approved. The whole Los Angeles project, from design through construction to the Certificate of Occupancy, typically takes six months to a year.

Can I rent my Los Angeles ADU on Airbnb?

No, an ADU or JADU permitted in Los Angeles must be rented for terms longer than 30 days under state ADU law, so nightly or weekly short-term rental is not allowed. Long-term rental or housing a family member is the intended use, and the unit cannot be sold separately from the house except under narrow AB 1033 conditions.

The state has found the City of Los Angeles ADU ordinance out of compliance

On 19 November 2024 the California Department of Housing and Community Development reviewed the City’s ADU ordinance — Ordinance No. 186481, passed in December 2019 — and concluded that it does not comply with state ADU law. The letter runs to seventeen findings. These are the ones that change what a homeowner can ask for:

• The ordinance limits a lot to one ADU. Government Code section 66323(a) requires a city to allow a combination: “one converted ADU, one detached…ADU, and one JADU.”
• It states a 16-foot height maximum. Section 66321(b)(4) requires 18 to 20 feet to be allowed near transit, with an allowance for roof pitch.
• It does not allow conversion of a detached accessory structure, which section 66323(a)(1)(A) requires.
• It counts ADUs toward allowable density. Section 66319 says an ADU “shall not be considered to exceed the allowable density.”
• The ordinance text applies park dedication fees to all ADUs, although the city’s fee guidance exempts ADUs from them; Government Code 66311.5(c) (formerly 66324(c)(1)) bars impact fees on units of 750 sq ft or less and requires proportional charging above that.
• Its owner-occupancy language conflicts with AB 976, in force since 1 January 2024.
• Its prohibition in Very High Fire Hazard Severity Zones lacks adequate evidence of a public safety impact under section 66314(a).
• It still cites Government Code sections 65852.2, 65852.22 and 65852.26, deleted in March 2024 and replaced by sections 66310–66342.

A second HCD letter, on 14 August 2025, settled a narrower point that is worth real money to some owners. The City had been applying a cap to unpermitted units it was asked to legitimize. HCD’s position: Government Code section 66332 requires approval of unpermitted ADUs created before 1 January 2020 and there is “no upper limit to that number in the statute”; section 66323(a)(3) separately requires ministerial approval of ADUs within parts of an existing multifamily building “that are not used as livable space”; and the City “may not use one section to preclude units under the other.” If you own a building with converted units that were never permitted, that is the letter to read before anyone tells you how many can be legalized.

If your address is in unincorporated Los Angeles County rather than inside the City, a different ordinance applies — and HCD found that one non-compliant as well, on 1 December 2025, against County Ordinance No. 2025-0029 adopted 29 July 2025. Check which jurisdiction you are actually in before you rely on either set of rules.

The practical consequence is the same in all of these cases: where a local ordinance is more restrictive than the statute, the statute controls. We would rather design to the state floor from the outset and have the letters on hand than discover the gap at plan check.

Sources

ADU law changes most years, and the Los Angeles ordinance is amended separately from the state statute. The rules below were checked against the current state sources on the date shown; confirm anything decision-critical with LADBS or City Planning for your specific lot.

• California HCD, review of the City of Los Angeles ADU ordinance (19 November 2024) — the finding that Ordinance No. 186481 does not comply with state ADU law, with seventeen specific issues including the one-ADU-per-lot limit, the 16-foot height maximum, density counting, park dedication fees and the Very High Fire Hazard Severity Zone prohibition.
• California HCD, letter of technical assistance to the City of Los Angeles (14 August 2025) — Government Code section 66332 has “no upper limit” on the number of pre-2020 unpermitted ADUs a city must approve, section 66323(a)(3) separately covers non-livable space in existing multifamily buildings, and a city “may not use one section to preclude units under the other.”
• California HCD, review of the Los Angeles County ADU ordinance (1 December 2025) — for unincorporated county addresses rather than the City: the finding that County Ordinance No. 2025-0029, adopted 29 July 2025, does not comply with state ADU law.
• California Department of Housing and Community Development, Housing Law Fact Sheets — Accessory Dwelling Units (April 2026) — confirms that ADU law sits at Government Code sections 66310–66342, that a city may not require rear and side setbacks greater than four feet for a new detached ADU, the 60-day decision deadline, and that impact fees may not be charged on an ADU of 750 square feet or less or on a JADU.
• California HCD, Accessory Dwelling Unit Handbook (March 2026) — the source for the guaranteed 800-square-foot unit: Government Code section 66321(b)(3) bars a city from applying lot coverage, floor area ratio, open space or minimum lot size standards that would not permit at least an 800 square foot ADU with four-foot side and rear setbacks, at a height of up to 16 feet.

Reviewed by Dekel Sofer, founder and CEO of Green Design and Build (California contractor license #1110975, Class B, General Building). Last reviewed 17 September 2026.

Find out what your Los Angeles lot allows

Send us the address and we will pull the zoning, hillside, fire-zone and transit flags, tell you whether you are building a state-law or ordinance ADU, and give you a written estimate for the unit that fits. Our office is at 16120 Sherman Way in Van Nuys, open every day from 8 AM to 6 PM; see our Los Angeles and Van Nuys pages for how we work across the city.