ADU Rules in Los Angeles County, California
We track 21 cities in Los Angeles County. Each city writes its own ADU ordinance on top of California law, so size limits, fees, and design rules differ from one city to the next. Among the cities we track, Long Beach has the lowest starting permit fees ($4,500 – $18,000).
Cities
21
Max Detached Size
1,000–1,200 sq ft
Build Costs From
$120,000
Pre-approved Plans
14 of 21 cities
Los Angeles County Cities Compared
| City | Max detached | Height | Permit fees | Build cost |
|---|---|---|---|---|
| Los Angeles | 1,200 sq ft | 16 ft (detached) | $5,000 – $25,000 | $150,000 – $450,000 |
| Long Beach | 1,200 sq ft | 16 ft detached | $4,500 – $18,000 | $150,000 – $420,000 |
| Santa Clarita | 1,000 sq ft | 16 ft (detached) | $7,000 – $16,000 | $150,000 – $320,000 |
| Glendale | 1,000 sq ft | 16 ft (hillside overlay may restrict further) | $9,000 – $20,000 | $160,000 – $370,000 |
| Palmdale | 1,200 sq ft | 16 ft (detached), 18 ft within half a mile walking distance of transit | $5,000 – $11,000 | $130,000 – $270,000 |
| Lancaster | 1,200 sq ft | 18 ft (detached), up to 20 ft to match the roof pitch of the main home | $4,500 – $9,500 | $120,000 – $250,000 |
| Pomona | 1,200 sq ft | 16 ft (detached) | $6,000 – $12,000 | $140,000 – $290,000 |
| Torrance | 1,200 sq ft | 16 ft (detached) | $9,000 – $18,000 | $175,000 – $360,000 |
| Pasadena | 1,200 sq ft | 16 ft detached (18 ft near transit or on a multistory lot, +2 ft for roof pitch near transit) | $5,000 – $22,000 | $170,000 – $480,000 |
| Downey | 1,000 sq ft | 16 ft | $7,000 – $14,000 | $150,000 – $310,000 |
| El Monte | 1,000 sq ft | 16 ft | $6,500 – $13,000 | $145,000 – $295,000 |
| Inglewood | 1,000 sq ft | One story and 16 ft (detached) | $8,000 – $16,000 | $160,000 – $330,000 |
| West Covina | 1,000 sq ft | 16 ft per the city ADU guide | $7,000 – $14,000 | $150,000 – $305,000 |
| Burbank | 1,000 sq ft | 17 ft detached (18 ft within 1/2 mile of transit) | $9,000 – $18,000 | $175,000 – $360,000 |
| Norwalk | 1,000 sq ft | 16 ft (detached) | $7,000 – $14,000 | $150,000 – $305,000 |
| South Gate | 1,000 sq ft | 16 ft (detached), plus 2 ft to match the roof pitch of the main home where state law allows | $7,000 – $14,000 | $145,000 – $295,000 |
| Compton | 1,200 sq ft | 16 ft detached (state law allows 18 ft within 1/2 mile of major transit) | $7,000 – $13,500 | $145,000 – $290,000 |
| Santa Monica | 1,200 sq ft | 24 ft / 2 stories (detached) | $6,000 – $28,000 | $200,000 – $600,000 |
| Hawthorne | 1,000 sq ft | 16 ft and one story under local code | $8,000 – $16,000 | $160,000 – $330,000 |
| Whittier | 1,200 sq ft | 16 ft (detached) | $7,500 – $15,000 | $155,000 – $315,000 |
| Alhambra | 1,200 sq ft | 25 ft (up to two stories) | $7,500 – $15,000 | $155,000 – $315,000 |
Los Angeles ADU rules
Los Angeles caps ADUs at 1,200 sq ft, with attached units limited to 50% of the existing home's living area. LADBS runs a Standard Plan Program with pre-approved designs, including a city-owned plan that is free to use, which cuts plan check time. Converted garages need no setbacks, while new detached units follow 4 ft side and rear setbacks and a 16 ft height limit.
Long Beach ADU rules
Long Beach has no local ADU ordinance of its own, so every ADU and JADU is reviewed directly against state ADU law. Coastal Zone lots need an administrative Local Coastal Development Permit before the building permit, and historic district lots need a Certificate of Appropriateness. The city also runs a pre-approved ADU plan program to shorten plan check.
Santa Clarita ADU rules
Santa Clarita limits ADUs to 850 sq ft for a studio or one-bedroom and 1,000 sq ft for two bedrooms, with 4 ft side and rear setbacks for new detached units. Much of the city lies in fire hazard severity zones and hillside areas, so fire-rated materials and soils reports are common added costs. The Planning Division updated its ADU handout in March 2026.
Glendale ADU rules
Glendale caps ADUs at 850 sq ft for one bedroom and 1,000 sq ft for two or more bedrooms, below the 1,200 sq ft many cities allow. Units over 800 sq ft must also fit within the zone's floor area ratio and lot coverage, which matters on the city's many hillside lots. The city has started a pre-approved ADU plan program, beginning with a 740 sq ft one-bedroom design.
Palmdale ADU rules
Palmdale's handout allows detached ADUs up to 1,200 sq ft, while attached ADUs can be 850 sq ft for 0-1 bedrooms or 1,000 sq ft for two or more, or 50% of the main home if that is larger. The city offers free conceptual Standard ADU Plans, but they are not construction-ready, so a designer still has to produce full plans. Applications start with a Zoning Clearance Review through the Accela citizen portal.
Lancaster ADU rules
Lancaster offers five pre-approved ADU designs by RRM Design Group, from 370 to 1,200 sq ft, sold through the city's permit portal. The city also runs an ADU Assistance Loan Program with up to $10,000 in deferred, no-interest funds for soft costs. Large Antelope Valley lots make detached units easy to site.
Pomona ADU rules
Pomona's ADU and JADU standards are in Zoning and Development Code Section 830.A, and planning questions go to the Planning Division counter. Lots range from compact downtown parcels to larger residential-agricultural lots, and older homes with detached garages make conversions common. Rental demand is steady from Cal Poly Pomona and Western University of Health Sciences.
Torrance ADU rules
Torrance applies detailed objective design standards to ADUs, such as matching materials and limits on new balconies and roof decks. The city's Building and Safety Division runs a Pre-Approved ADU Program with plans roughly 80% ready for permitting, pre-reviewed by both Building and Planning. Hillside Overlay and Coastal Zone lots can face tighter limits than the rest of the city.
Pasadena ADU rules
Pasadena regulates ADUs in Zoning Code Section 17.50.275, with 4 ft side and rear setbacks for new units and the base zone front setback. The city's ADU Standard Plans expired on December 31, 2025 with the building code update and can now only be used on properties red-tagged in the Eaton Fire, with new citywide plans promised. Properties in historic districts need a Certificate of Appropriateness, which adds review time.
Downey ADU rules
Downey updated its ADU and JADU ordinance in June 2026 to match new state laws, including AB 1154 limits on JADU owner-occupancy covenants and SB 543 permit rules. The city runs a pre-approved detached ADU plan program, though plans are about 80% complete and need site-specific work by the original designer. Standard 6,000 to 7,000 sq ft lots usually fit a detached unit.
El Monte ADU rules
El Monte offers an ADU/JADU loan program to help eligible homeowners build a new unit or convert existing space. The city expects ADUs to match the style and materials of the main house, and has a formal addressing policy for new units. Compact lots and 1950s to 1970s housing make garage conversions the most common route.
Inglewood ADU rules
Inglewood's ADU rules are in Article 35 of the zoning code, and the city publishes a 2024 ADU Development Standards sheet. HCD reviewed the ordinance in May 2025, and where local limits such as one-story detached ADUs conflict with state law, state law controls. Parcels near LAX may carry noise overlays or avigation easement requirements.
West Covina ADU rules
West Covina does not let ADUs or JADUs have their own address or separate utility service, which matters if you plan to rent the unit. The city offers pre-approved detached ADU designs through a Pre-Approved Second Unit Review application, along with example plans for garage conversions. Many lots are 7,000 sq ft or larger, leaving room for a detached unit up to 1,000 sq ft.
Burbank ADU rules
Burbank has its own Pre-Approved ADU Program (BPAP) with a library of plans that skip architectural, structural and energy plan check, aiming for permits in about 30 days. Height rules are more detailed than state law: detached units top out at 17 ft (18 ft near transit), while units over a garage can reach 23 ft. Any part of an ADU with interior height over 12 ft counts as two stories for floor area.
Norwalk ADU rules
Norwalk publishes an ADU Guidebook and ADU Checklist and allows attached, detached, junior and multifamily ADUs under its zoning code. Much of the housing is post-war tract homes with detached garages that convert well, and some older blocks have alley access. Sewer connection is through LA County Sanitation, with fees billed separately from city permits.
South Gate ADU rules
South Gate's small, dense lots make garage conversions the most common ADU here, and the city supports them directly with three Garage Conversion Standard Plans plus permit-ready plans for new detached units. Every ADU or JADU goes through building plan check, and the city requires a full kitchen, bathroom and separate entrance. HCD issued a review letter on the city's ADU ordinance in March 2026, so check the planning page for the latest standards.
Compton ADU rules
Compton requires a recorded covenant for every ADU or JADU, and since December 2021 that covenant bars short-term rentals under 30 days. Detached garages are common on local lots, making garage conversions the usual path. HCD reviewed Compton's ADU ordinance in 2025, so confirm current standards with the Planning Division.
Santa Monica ADU rules
Santa Monica is more generous than state minimums on height: a detached ADU can be two stories or 24 ft tall, and ADUs do not count toward lot coverage or floor area. Side and rear setbacks are 4 ft, with a 6 ft separation from the main house. Coastal Zone parcels may need extra review, and the city runs a preapproved detached ADU plan program.
Hawthorne ADU rules
Hawthorne's code caps attached and detached ADUs at 1,000 sq ft and limits them to one story and 16 ft, though state law allows more height near transit and for attached units. HCD sent the city a technical assistance letter on its ADU ordinance in December 2025, so check for updates before designing. The city offers three free pre-approved detached plans that are submitted with a site plan through its online portal.
Whittier ADU rules
Whittier offers preapproved one-story detached ADU plans from a 311 sq ft studio to an 800 sq ft two-bedroom, in Craftsman, Spanish or Traditional styles. The plans include solar panels and a fire sprinkler system, and you must sign a Hold Harmless Agreement before submitting. Older neighborhoods with detached garages are good candidates for conversions.
Alhambra ADU rules
Alhambra is one of the few San Gabriel Valley cities that lets ADUs go up to two stories and 25 ft, so a second-story unit over a garage or a two-level backyard unit is possible here. Detached ADUs can reach 1,200 sq ft with 4 ft side and rear setbacks. Lots are tight, so check utility capacity early.
Rules that apply in every California city are summarized in our California ADU law guide. See all California cities or compare every city side by side.