Cost guide · updated October 2026
ADU Cost in Los Angeles
Published 2026 cost figures for detached ADUs, garage conversions and junior ADUs in Los Angeles, with the fees, permit rules and timelines that change the total. These are market figures. Your own number depends on your lot.
Short answer
How much does an ADU cost in Los Angeles?
Angi's 2026 cost guide puts an ADU in Los Angeles at $150,000 to $375,000. A garage conversion usually costs less: Angi gives a California average of $160,000, and LA-area garage conversions profiled by Block Renovation had published totals of $75,000 to $300,000. State law waives impact fees on an ADU of 750 square feet or less and gives the city 60 days to approve or deny a complete application on a lot that already has a house.
- Any ADU, Los Angeles
- $150,000 to $375,000 (Angi, 2026)
- Garage conversion
- $60,000 to $150,000 nationally; $160,000 California average (Angi)
- Junior ADU
- Up to 500 sq ft inside the house
- Impact fees
- None at 750 sq ft or less
- School fees
- Only above 500 sq ft; state cap $5.38 per sq ft (2026)
- City review
- 15 business days to check completeness, then 60 days to decide
- Parking
- No replacement parking for a garage converted to an ADU
The numbers
Published ADU cost figures for Los Angeles (2025 to 2026).
| ADU type | Published figure | Source and what it covers |
|---|---|---|
| Any ADU, Los Angeles | $150,000 to $375,000 | Angi ADU cost guide, updated May 2026. Angi's range for Los Angeles. |
| Detached ADU, new construction | $110,000 to $285,000 | Angi, national range before permits and fees. |
| Detached ADU, Los Angeles | $300,000 to $450,000 or more | Block Renovation ADU cost guide, 2026. Block doesn't say how it built this figure. |
| Garage conversion ADU | $60,000 to $150,000 (average $110,000) | Angi garage-to-ADU guide, 2026 data, national. |
| Garage conversion ADU, California | $160,000 average | Angi, state table. |
| Garage conversion ADU, LA-area projects | $75,000 to $300,000 | Published totals for the LA-area projects profiled by Block Renovation, August 2026. |
| Cost per square foot | $150 to $300 | Angi, national average for all ADU types. Block Renovation's example: about $350 per sq ft for a 500 sq ft unit and $275 for an 800 sq ft unit on the same lot. |
Sources: Angi (updated May 30, 2026), Angi garage-to-ADU guide (2026 data) and Block Renovation (2026). For an older benchmark, a Terner Center survey of California ADU owners published in 2021 found a median cost of $150,000, or $250 per square foot. These are market figures. Kasimov Construction doesn't publish a price list. You get a written fixed price for your project after a free estimate visit.
Fees and permits
What you pay the city, the schools and the utilities.
In the City of Los Angeles, ADU permits come from LADBS. Burbank, Glendale, Pasadena, Santa Monica, Beverly Hills and other cities run their own building departments, so check which office permits your address. The plan check notes are for LADBS. The impact, school and utility fee rules are state law and apply in every city.
Plan check and permit fees
LADBS bases building plan check and permit fees on the project valuation, meaning the total cost of construction (LADBS Standard Plan Program). You can get a first number from the LADBS plan check fee estimator. Pre-approved standard plans shorten plan check, but LADBS still reviews zoning and the foundation for your lot.
Impact fees: none at 750 square feet or less
Under state ADU law (Gov. Code §66311.5), cities, special districts and water companies can't charge impact fees on an ADU with 750 square feet of interior living space or less. That includes park (Quimby) fees. Above 750 square feet, the fee has to be proportional to the size of the main house. HCD's example: a 1,000 sq ft ADU next to a 2,000 sq ft house can be charged up to 50% of the fee for a new house. A JADU of 500 square feet or less pays no impact fees.
School fees: only above 500 square feet
School districts may charge school impact fees on an ADU larger than 500 square feet. Smaller ADUs and JADUs are exempt. The state cap on the basic (Level 1) residential school fee is $5.38 per square foot as of January 2026. Each district sets its own rate up to the cap, so ask for the current LAUSD rate at plan check.
Water, sewer and power
- An ADU built inside existing space, such as a garage, and a JADU don't count as a new home for utility connection fees or capacity charges, unless they're built together with a new house.
- Where a connection fee does apply, it has to be proportional to the ADU's size or plumbing fixtures compared with the main house.
- LADBS requires a separate electrical panel and a separate water shut-off valve for an ADU. A detached ADU can share the house's drain line if that line meets the plumbing code (LADBS bulletin P/BC 2026-150).
- Before the permit is issued, the Bureau of Engineering checks sewer availability and the Fire Department checks hydrants and access.
Rules that add cost to a new detached ADU
- Solar. A newly built detached ADU falls under the Energy Code solar requirement, with some exceptions. The panels can go on the ADU or on the main house.
- Fire sprinklers. Required only if the main house has to have them. Building an ADU doesn't trigger sprinklers in the house.
- Setbacks and height. State law allows a detached ADU with 4-foot side and rear setbacks and a base height of 16 feet.
Price drivers
What moves the number up or down.
- New build or conversion. A garage conversion reuses the slab, walls and roof. Angi's 2026 table puts garage conversions at $60,000 to $150,000 and detached new construction at $110,000 to $285,000.
- Utility runs. The distance to the sewer line, water and power. Angi says a detached garage needs new underground lines, which adds 20% to 30% to a conversion.
- Electrical capacity. LADBS requires a separate panel for the ADU. Whether the main service can carry the new load depends on the house.
- Size and wet rooms. A kitchen and a bathroom cost about the same in a small unit as in a large one, so smaller ADUs cost more per square foot.
- Design and engineering. Angi puts design at 10% to 15% of the project. LADBS pre-approved standard plans can shorten plan check.
- Size thresholds. Above 500 sq ft, school fees can apply. Above 750 sq ft, impact fees can apply.
- Site. Slope, soil, access for materials and how far the unit sits from the street.
- Finish level. A rental unit and a unit for family often get different finishes.
Timeline
How long does an ADU take in Los Angeles?
| Stage | What happens | Typical time |
|---|---|---|
| Feasibility and design | Survey, site plan, floor plan, structural and Title 24 energy calculations. | Usually 1 to 3 months |
| Completeness check | The city confirms the application has everything it needs. | Up to 15 business days |
| Approval or denial | Plan check and corrections. A denial has to list what to fix. | Up to 60 days from a complete application |
| Construction | Foundation or conversion work, framing, utilities, inspections and finishes. | Usually 4 to 8 months |
| Final | Clearances, final inspection and the certificate of occupancy. | Scheduled with LADBS |
Review deadlines: HCD ADU Handbook, March 2026 (Gov. Code §66317). Design and construction times are our typical ranges and change with the scope. For comparison, the LA-area garage conversions profiled by Block Renovation took 10 to 52 weeks.
Junior ADUs
What does a junior ADU (JADU) cost?
The cost guides we used for this page don't publish a separate figure for JADUs, so we don't quote one. A JADU is built inside the house, so it skips the foundation, roof and long utility runs that drive the price of a detached unit. The biggest variable is plumbing: whether you add a bathroom, and how far the new drains have to run.
The rules for a JADU under state law:
- Up to 500 square feet of interior living space, inside a single-family home. An attached garage counts as part of the house.
- An efficiency kitchen: cooking appliances, a prep counter and storage of reasonable size. A 220-volt circuit isn't required.
- Its own bathroom or a shared one. Without its own bathroom, it needs an interior door to the main house.
- If it shares a bathroom with the house, the owner has to live on the property. Rentals must be longer than 30 days.
- No parking can be required, even when the JADU replaces an attached garage.
- No impact fees and no new utility connection fees at 500 square feet or less.
How much does an ADU cost in Los Angeles?
Do I pay impact fees on an ADU in Los Angeles?
Do I have to pay school fees on an ADU?
How long does the city take to approve an ADU?
Is a garage conversion cheaper than a detached ADU?
Do I have to replace parking when I build an ADU?
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