- Typical cost
- $120k to $400kConversion is cheapest, detached costs most
- Start to finish
- 9 to 16 monthsPermits are 2 to 4 months of it
- Allowed on your lot?
- Almost certainlyState law overrides most local bans
- Rents for
- Varies by areaOften covers the construction loan
An ADU is a second, legal home on your lot. It can be a detached unit in the backyard, an addition with its own front door, a converted garage, or a small unit carved out of the house. State law has made them legal on nearly every residential lot in California, and Los Angeles builds more of them than anywhere else in the state.
We build them for homeowners who want rent or room for family, and for investors adding units to houses and apartment buildings. We handle the lot check, the drawings, the utilities, the permit and the build through to the day the city signs off and the unit gets its own address.
What it costs in Los Angeles
| What | Typical Los Angeles range | Notes |
|---|---|---|
| Junior ADU, inside the house | $60,000 to $120,000 | Up to 500 sq ft, may share a bathroom |
| Garage conversion | $120,000 to $150,000 | 350 to 400 sq ft, reuses the structure |
| Detached ADU, 400 to 500 sq ft | $150,000 to $200,000 | Studio or small one-bedroom |
| 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 | Or $350k to $400k two-story |
| Utility work that catches people out | $10,000 to $60,000 | Sewer upsizing, panel upgrade, separate meter |
Planning ranges for Los Angeles County, reviewed 2026-10-29. Not a quote. We price every job after walking it.
What's included
- A lot check: setbacks, height, utilities and what the city will allow
- Drawings, energy-code paperwork and structural engineering
- Permit filing and the back-and-forth with the city
- Sewer, water, gas and electrical hookups, with a separate meter if you want one
- Foundation, framing, roofing, insulation and the full interior
- Kitchen, bathroom, laundry and heating and air
- Fire separation and escape windows where the code requires them
- Final inspection, certificate of occupancy and a new address
What drives the price
- Converting something that exists versus building new from the ground
- How far the unit sits from the sewer, and whether the main line can handle another unit
- Whether your electrical panel has room, and whether you want a separate meter
- Getting equipment into the backyard: access, slope, trees, and anything that has to come down first
- Finish level, and whether you are renting it out or putting family in it
Permits and approvals
ADUs are allowed by right on most residential lots under state law, and the city has to approve or deny a complete application within 60 days. Real-world timelines run 2 to 4 months once you count the corrections the city sends back. New detached units get 4-foot side and rear setbacks and at least 16 feet of height. A converted garage keeps the setbacks it already has. The City of Los Angeles also has pre-approved standard plans that skip most of the design review.
How long it takes
Drawings and engineering take 4 to 8 weeks. Permits take 2 to 4 months. Construction is 3 to 5 months for a garage conversion and 5 to 8 months for a detached unit. New utility meters run on the utility company's schedule, not ours, so we start those applications early.
Three ways to scope it
Garage conversion
Turns the garage into a studio or one-bedroom. Cheapest per unit because the slab, walls and roof already exist. Usually needs a new slab, insulation and all-new plumbing and wiring.
Detached new build
A freestanding unit up to 1,200 square feet. You control the layout, it rents for the most, and it costs the most.
Attached or junior
An addition with its own entrance, or a small unit (up to 500 sq ft) inside the existing house with a compact kitchen.
How we run the job
1. Walk the property
We meet you on site, listen, and look at what the building and the city will need. You get a written scope and a budget range.
2. Drawings
When drawings are needed we bring in the architect and engineer, and price the design while it is being drawn.
3. Permit
We file with the city, handle the corrections they send back, and tell you where it stands.
4. Price and contract
An itemized price, a schedule and payment terms. Anything new after signing gets priced in writing first.
5. Build
One supervisor on your job, licensed trades, inspections in order, and a weekly update with photos.
6. Walkthrough
A final fix list, the city's sign-off, and a written warranty on our work.
Questions
Can I build an ADU on my lot?
Almost certainly. State law requires cities to allow at least one ADU and one junior ADU on single-family lots, and multiple units on apartment lots. Hillside, fire-zone and historic properties get extra conditions but are rarely flat-out prohibited. We confirm it with a parcel check.
Do I have to replace the parking I lose?
No. State law bars cities from making you replace parking when you convert a garage into an ADU.
Can I rent it out?
Yes, as a long-term rental of 30 days or more. Short-term rental of an ADU is restricted in the City of Los Angeles and most surrounding cities.
Can I sell it separately from the house?
Only in cities that have opted in to the state law allowing it, and most have not. Assume the ADU stays part of your parcel unless we confirm otherwise for your city.
What does it rent for?
It depends on the neighborhood, the size and the finish. A one-bedroom in a central or westside neighborhood commonly rents in the low-to-mid $2,000s or above. We will run the numbers with you before you pay for drawings.
Will it raise my property taxes?
Yes, by the value of the new construction only. The existing house keeps its Proposition 13 assessment. On a $200,000 ADU expect roughly $2,200 to $2,500 a year, which is a small share of what it rents for.
ADU & Garage Conversion by city
Same work, different building department. Pasadena, Beverly Hills, Culver City, Long Beach, Santa Monica, Burbank, Sherman Oaks, Encino, Glendale, Studio City, West Hollywood. Or see every city.
Related reading
- How much does an ADU cost in Los Angeles?
- What is a garage conversion ADU?
- Can I build an ADU on my property in Los Angeles?
- What is a junior ADU (JADU)?
- What are the ADU setback and height rules in Los Angeles?
- What permits do I need for an ADU in Los Angeles?
- How much does it cost to convert a garage to an ADU?
Related work
Room Additions
More square footage: a bedroom, a primary suite, a bigger family room, or a whole second floor.
Ground-Up New Construction
Starting from an empty lot or a teardown and ending with a finished building.