Everything homeowners need to know about building an accessory dwelling unit in Los Angeles - size limits, setbacks, permits, and how the city's ordinance layers on top of California's statewide by-right ADU law.
Last verified: August 2026
9/10 · Very ADU-friendly
1,200 sq ft*
Max ADU size
16 ft*
Max height
Not required
Owner-occupancy
By-right
Permit type
This page summarizes Los Angeles Municipal Code Section 12.22 A.33 (Accessory Dwelling Units) and California's statewide ADU law (Government Code Section 65852.2) for general reference - it is not legal advice. Regulations change; always confirm current requirements with the LA Department of Building and Safety (LADBS) or LA City Planning before designing or applying for permits. See sources below.
Zoning & size requirements
What you're allowed to build
ADU type
Max size
Max height
Notes
Detached (new build or garage conversion)
1,200 sq ft
16 ft (up to 18 ft within a half-mile of transit or on a multifamily lot; taller two-story designs are allowed on some qualifying properties)
1,200 sq ft or 50% of the primary dwelling's floor area, whichever is smaller
Matches the primary structure, up to 25 ft / 2 stories
Common approach for basement or above-garage conversions
Junior ADU (within existing walls)
500 sq ft
Same as primary structure
Must be carved from existing living area; owner-occupancy still generally required for JADUs specifically
Allowed zoning districts
All residential zones citywide (R1, R2, R3, R4, R5, RD, RW1, RW2, RE, RS, RA) under LAMC 12.22 A.33. Confirm your parcel's zone and any hillside, historic, or coastal overlay through LADBS's ZIMAS tool.
Additional standards
Setbacks, parking & other rules
Setbacks
4 ft from side and rear property lines for ADUs up to 16 ft tall; front setback generally matches the primary dwelling or base zone requirement; conversions of existing structures typically need no added setback
Parking
No additional off-street parking required for the ADU itself, eliminated statewide by AB 68
Units per lot
1 ADU + 1 JADU on a single-family lot. Multifamily properties may convert up to 25% of existing non-livable space and add new detached ADUs; state law under SB 1211 allows qualifying multifamily lots to add up to 8 detached ADUs
Owner-occupancy
Not required for ADUs, permanently eliminated statewide by AB 976 effective January 1, 2024. JADUs generally still require the owner to occupy either the primary residence or the JADU
Building code
Must meet California Residential Code / California Building Code dwelling-unit standards, plus Title 24 energy requirements
Rental & short-term rental
No separate license is required to rent an ADU long-term. Short-term/home-sharing use is restricted to ADUs with a certificate of occupancy issued before January 1, 2017, and only when the unit is the host's primary residence, under the city's Home-Sharing Ordinance
Ordinance history
How Los Angeles's ADU rules got here
2016Statewide ADU law arrives. Governor Brown signs SB 1069 and AB 2299, effective January 1, 2017, creating the first modern statewide ADU framework and voiding any local ordinance that doesn't align with it. LA City Planning issues a stopgap Zoning Administrator interpretation on November 2, 2016 while it drafts a compliant local ordinance.
2019LA adopts its own ADU ordinance. Ordinance 186,481, adopted December 11, 2019 and effective December 19, 2019, creates LAMC 12.22 A.33 with local development standards for ADUs, JADUs, and movable tiny houses.
2020State law strengthens ministerial review. AB 68, AB 881, AB 670, and SB 13 take effect January 1, 2020, mandating 60-day ministerial approval, cutting setbacks to 4 ft, and temporarily barring owner-occupancy requirements.
2023Setbacks and heights loosen further. AB 2221 and SB 897 take effect January 1, 2023, reducing setbacks and raising allowable heights, further narrowing what cities can restrict.
2024Owner-occupancy ban made permanent; permit volume climbs. AB 976, effective January 1, 2024, permanently prohibits California cities from requiring owner-occupancy for ADUs. That year, Los Angeles permitted 6,626 ADUs, its second-highest annual total on record and roughly 43% of all new residential units permitted citywide.
2025Multifamily ADU capacity expands. SB 1211 takes effect January 1, 2025, allowing qualifying multifamily properties to add up to 8 detached ADUs.
Los Angeles County has been cited in industry permit-tracking reports as having approved more than 126,000 ADUs since 2018, and an analysis of LA County permit records found homeowners have invested billions in ADU construction over that span. Within the city itself, ADUs have become a major driver of new housing supply at a time when conventional apartment permitting has slowed to its lowest level in over a decade.
Permit process
How Los Angeles ADU permitting works
1
Confirm zoning eligibility
Check your parcel's zone and any hillside, historic, or coastal overlay through LADBS's ZIMAS tool before you design.
2
Choose a plan path
Use the city's ADU Standard Plan Program for pre-approved plans and faster review, or submit a fully custom design.
3
Prepare your plan set
You'll need a site plan, floor plans and elevations for the ADU, plus floor plans of the existing house if you're relying on the 50%-of-primary-dwelling size formula.
4
Submit for plan check
File through LADBS's online Express Permit system or in person; qualifying ADUs receive streamlined, ministerial review.
5
Plan review
State law requires a decision within 60 days of a complete application.
6
Permit, build, inspect
Pull your building permit, begin construction, and schedule framing, plumbing, electrical, and final inspections through certificate of occupancy.
Total permit and plan-check fees typically run $5,000-$14,000 depending on project size and construction valuation. Fees and timelines are approximate - confirm current figures with LADBS.
Budgeting
What it costs to build an ADU in Los Angeles
Garage conversion
Roughly $120,000-$220,000 (about $250-$400 per sq ft), the least expensive path since the slab and walls already exist
Basement conversion
Uncommon in Los Angeles's housing stock, since most single-family homes here are built slab-on-grade without a true basement. Where feasible, costs run comparable to or higher than a garage conversion - confirm with a local contractor
New detached ADU
Roughly $250,000-$400,000+ (about $350-$600 per sq ft) for a fully permitted, code-compliant freestanding unit
Permit & plan-check fees
Roughly $5,000-$14,000 total, scaled to construction valuation - which has itself risen from an average of about $74,000 per project in 2018 to around $200,000 in 2026
General Plan Maintenance Surcharge
An added 10% surcharge on permit fees, in effect as of June 9, 2026
These are general ranges from local contractor estimates and regional reporting, not quotes - actual cost depends heavily on lot conditions, site access, finishes, and whether utilities need to be extended. Southern California labor and land costs push Los Angeles ADU pricing well above national averages.
Before you apply
Tips for a smooth approval
Confirm your zone and any overlay before you design. Hillside, historic, and coastal overlays can add real requirements that a standard residential zone wouldn't have.
Consider the ADU Standard Plan Program. Pre-approved plans can meaningfully cut plan-check time compared to a fully custom design.
Double-check the attached-ADU size formula against your actual house. The 1,200 sq ft cap only applies if 50% of your home's floor area is larger.
Budget around construction valuation, not just square footage. Permit and plan-check fees scale with valuation, which has climbed sharply since 2018.
Decide on rental plans before you build. Only ADUs with a pre-2017 certificate of occupancy can legally home-share; everything else built under the current ordinance is long-term rental only.
FAQ
Common questions
Do I need to live on the property to build an ADU in Los Angeles?
No. California's AB 976 permanently eliminated owner-occupancy requirements for ADUs statewide as of January 1, 2024, so you can build and rent out an ADU without living on site. Junior ADUs (JADUs) generally still require an on-site owner.
How many ADUs can I build on one lot?
On a single-family lot, 1 ADU plus 1 JADU in addition to the primary dwelling. Multifamily properties can convert existing non-livable space and add new detached units, with state law allowing up to 8 detached ADUs on qualifying multifamily lots.
Do I need extra parking for an ADU?
No. Off-street parking requirements for ADUs were eliminated statewide by AB 68.
How long does the permit process take?
State law requires a ministerial decision within 60 days of a complete application. Total time to permit, including plan preparation, commonly runs a couple of months - confirm current timelines with LADBS.
What's the maximum size for a detached ADU?
1,200 sq ft, with a 16 ft height limit (up to 18 ft within a half-mile of transit or on a multifamily lot).
How much does an ADU cost to build in Los Angeles?
Garage conversions tend to run roughly $120,000-$220,000, and new detached units roughly $250,000-$400,000 or more, based on local contractor estimates and regional reporting - not counting permit and plan-check fees, which typically add another $5,000-$14,000.
How many ADUs has Los Angeles actually permitted?
The city permitted 6,626 ADUs in 2024 alone, its second-highest annual total on record and roughly 43% of all new residential units permitted that year. Industry permit-tracking reports put the countywide total at more than 126,000 ADUs approved since 2018.
Can I rent my ADU out on Airbnb or a short-term rental platform?
Generally no. Under the city's Home-Sharing Ordinance, only ADUs with a certificate of occupancy issued before January 1, 2017 can be used for short-term rental, and only when the unit is the host's primary residence. Any other ADU is long-term rental only.
