You can almost certainly build an ADU in Long Beach. California law requires every city to allow at least one ADU and one junior ADU on a single-family lot, protects an 800 square foot unit with four-foot side and rear setbacks at 16 feet of height, bars cities from requiring replacement parking for a garage conversion, and gives the city 60 days to approve or deny a complete application. Long Beach applies its own design standards and fees on top of that floor.
- Building department
- Long Beach Development Services
- State floor
- 800 sq ft protected4 ft setbacks, 16 ft height
- Decision deadline
- 60 daysOn a complete application
- Typical all-in cost
- $120k to $400kConversion through detached
What state law guarantees you, here and everywhere
- At least one ADU and one junior ADU on a single-family lot
- An 800 square foot unit with 4-foot side and rear setbacks at 16 feet of height, which no local lot-coverage, floor-area or open-space rule can block
- 18 feet of height near major transit or on a lot with an existing multi-storey multifamily building, plus 2 feet to match the main roof pitch
- No replacement parking when you convert a garage
- No owner-occupancy requirement for a full ADU
- A decision within 60 days of a complete application, with 15 business days for the city to confirm completeness
A city cannot opt out of these. Where a local ordinance conflicts with state law, state law governs, and local ADU ordinances that are not properly submitted to the state housing department can be void entirely.
What is specific to Long Beach
Long Beach runs its own development services department and publishes pre-approved ADU plans, which is the single biggest timesaver available on an ADU anywhere. Where a standard plan fits the lot, the architectural review has already been done and plan check becomes a short exercise rather than a long one.
The city's neighbourhoods vary enormously, from Belmont Shore and Naples near the water to the larger inland lots of Bixby Knolls and Los Altos. Coastal zone rules apply near the water and add a layer of review that inland parcels do not carry.
Long Beach also has designated historic districts with design review for exterior changes, and a mandatory seismic retrofit programme for certain building types.
- The city publishes pre-approved ADU plans, which cut plan review sharply
- Coastal zone rules apply to parcels near the water
- Historic districts review street-facing exterior changes
- Larger inland lots in Bixby Knolls and Los Altos suit detached units
Local ordinances, fees and plan availability change faster than any website. We confirm the current Long Beach requirements against your specific parcel before anything is drawn, and that check costs you nothing.
What it costs
| What | Typical Los Angeles range | Notes |
|---|---|---|
| Junior ADU, inside the house | $60,000 to $120,000 | Up to 500 sq ft |
| Garage conversion | $120,000 to $150,000 | 350 to 400 sq ft |
| Detached ADU, 600 to 800 sq ft | $200,000 to $250,000 | Standard finishes |
| Detached ADU, 1,000 to 1,200 sq ft | $300,000 to $350,000 | Larger units |
Work out your own number. The ADU cost calculator gives you a line-item range for your lot and unit type in under a minute.
Los Angeles County figures, reviewed 2026-10-29 by America General Contractors, California contractor licence CSLB 1083262. Planning ranges, not a quote, and not legal advice. We confirm the current rules for your parcel before anything is drawn.
Questions
Can Long Beach refuse my ADU?
Not on a standard unit meeting the state's objective standards. Long Beach applies its own design standards and fees, and reviews the site-specific parts, but it cannot refuse an ADU that meets state law. Hillside, fire-zone and historic conditions add requirements rather than a veto.
How long does an ADU permit take in Long Beach?
State law gives the city 60 days to decide a complete application, plus 15 business days to confirm completeness. Real timelines run two to four months once correction rounds are counted. A pre-approved standard plan, where the city offers one and it fits your lot, is far faster.
Do I need to live on the property?
Not for a full ADU. That requirement was removed permanently by state law. For a junior ADU it can still apply where the junior unit shares a bathroom with the main house.
Can I rent it short term?
Generally no. ADU short-term rental is restricted across the region, and junior ADU rentals must run longer than 30 days under state law.
Do you build in Long Beach?
Yes. We are a licensed California general contractor, CSLB 1083262, working across all of Los Angeles County, and we handle the drawings, the permit and the build.
Related reading
- Can I build an ADU on my property in Los Angeles?
- What are the ADU setback and height rules in Los Angeles?
- What permits do I need for an ADU in Los Angeles?
- What is a junior ADU (JADU)?
- ADU Cost Per Square Foot in Los Angeles
- Garage Conversion Cost in Los Angeles
- Does an ADU Raise Your Property Taxes?
- Pre-Approved ADU Plans in Los Angeles
