Find Trusted ADU Contractors in Los Angeles
GreatBuildz matches you with reliable, thoroughly vetted ADU contractors for free. We screen every builder in our network and stay involved from design through final inspection.
Trusted by homeowners across California
Most new-construction accessory dwelling units in Los Angeles cost $150,000 to $400,000 and take 6 to 9 months from design through final inspection. A garage conversion ADU runs $120,000 to $150,000 and takes 5 to 6 months.
GreatBuildz matches you with three ADU contractors who build in your city, and it costs you nothing. Every one passes our 10-point vetting process and signs our Code of Conduct: license, insurance, background check, references, past work, and a financial review.
We started in Los Angeles and now cover Los Angeles, Orange County, Ventura County, San Diego, the Inland Empire, and the Bay Area. Talk to an advisor, compare three estimates, and keep us in your corner through final inspection.
The perfect contractor in 3 easy steps
Why Homeowners Choose GreatBuildz
Truly vetted ADU contractors
Every contractor in our network passes a 10-point screening: license verification, insurance, background check, references, past work, and more. Only the top 5 to 10 percent make the cut.
Completely free for homeowners
Contractors pay to be part of our network. You pay nothing, and we don't sell your information to a list of strangers.
You get a dedicated remodeling advisor
A real person stays in your corner from the first call, helping you compare bids, understand what is included, and set a realistic ADU budget before you sign anything. Most homeowners say it is the part they didn't know they needed.
We stay involved and hold contractors accountable
An ADU takes months, not weeks. We check in throughout the build and step in if anything goes sideways, from plan check to final inspection. We don't take kickbacks for steering you to a specific contractor, and our contractors know our reputation rides on their work.
Types of ADUs We Match Contractors For
An accessory dwelling unit is a full, self-contained home on your property, with its own kitchen, bathroom, and entrance. Most Los Angeles projects fall into one of these types:
Detached ADU
A standalone backyard home. The most popular type in LA, and the one with the most design freedom. State law requires at least 4 feet of setback from side and rear property lines.
Attached ADU
Built onto the existing house with its own separate entrance. Often the practical choice on narrower lots where a detached unit won't fit.
Garage conversion ADU
Your existing garage becomes a living unit. The most affordable path to an ADU because the structure and slab already exist.
Junior ADU (JADU)
A unit of up to 500 square feet created within the walls of your existing home. If it has its own bathroom, there's no owner-occupancy requirement, and it's the lowest-cost option.
Above-garage ADU
A new unit built over an existing or rebuilt garage. Keeps the yard intact, though structural work makes it pricier than a standard conversion.
Two-story ADU
Maximum square footage on a small footprint. The most complex and most expensive build, and the one where contractor experience matters most.
Not sure which type fits your lot and budget? That's a normal place to start. Tell us what you're trying to do (rental income, family housing, a home office) and we'll match you with ADU contractors who build that type every week.
Costs
How Much an ADU Costs in Los Angeles
Most new-construction ADUs in Los Angeles cost $150,000 to $400,000, which works out to roughly $300 to $450 per square foot. A garage conversion ADU typically runs $120,000 to $150,000. On top of construction, plan on $8,000 to $20,000 for building plans and $5,000 to $20,000 for plan check, permit, and city impact fees.
The most affordable ADU. The slab, walls, and roof are already there, so your budget goes into conversion, utilities, and finishes.
The classic backyard unit: studio to two-bedroom, built from the ground up with its own utilities and entrance.
Full-size homes with multiple bedrooms. Two-story builds sit at the top of the range because of the structural work involved.
ADU construction cost by size
| Garage conversion | $120,000 to $150,000 |
| 400 to 500 square feet | $150,000 to $200,000 |
| 600 to 800 square feet | $200,000 to $250,000 |
| 800 to 1,000 square feet | $250,000 to $300,000 |
| 1,000 to 1,200 square feet | $300,000 to $350,000 |
| Two-story ADU | $350,000 to $400,000 |
Budgeting an ADU is where most projects go wrong
Construction is only part of the number. Plans run $8,000 to $20,000 and city fees another $5,000 to $20,000, and two identical floor plans can price differently on different lots. Our Remodeling Advisors will help you build a realistic all-in budget before you ever meet a contractor.
For the full breakdown, see ourguide to ADU costs in Los Angeles
Ready to start your ADU project?
Tell us about your project and we’ll connect you with three vetted local contractors. It’s free, with no obligation.
Timeline and permits
ADU Timeline, Permits, and California ADU Laws
A garage conversion ADU typically takes 5 to 6 months from design through final inspection. A new-construction ADU typically takes 6 to 9 months. California's ADU laws are the most homeowner-friendly they've ever been, and knowing a few of them keeps your project from stalling.
Plans, engineering, Title 24 energy calcs, and city plan check before construction can start.
Conversion construction moves fast because the structure already exists. About 5 to 6 months total including design and permits.
Foundation through final inspection for a ground-up unit. About 6 to 9 months total including design and permits.
California ADU laws working in your favor
Permits in Los Angeles
Every ADU needs building permits, and your plans go through plan check with your city’s building department (LADBS in the City of Los Angeles). Expect plan check, permit, and impact fees of $5,000 to $20,000 combined, and multiple rounds of plan corrections on many projects.
Because LA County includes 88 cities, the details shift from one jurisdiction to the next. A contractor who has permitted ADUs in your specific city is worth real money in avoided delays.
Deposit rule worth knowing
California law caps the deposit a contractor can ask for at $1,000 or 10 percent of the contract price, whichever is less. On a project this size, a contractor asking for a huge deposit upfront is a serious red flag, and it's one of the things our vetting screens out.
Reviews
Real ADU Projects and Reviews
Here are a few recent ADUs completed by contractors in our network, along with what the homeowners had to say.
"We’ve had a great experience working with GreatBuildz. Their team is professional, responsive, and does a great job connecting homeowners with qualified contractors."
Anna K, West LA
"Heather and GreatBuildz has been great to deal with. Was very helpful in providing good workers to facilitate getting work done on my ADU."
Gary B, Pasadena
"They connected us with a wonderful contractor who did the job quickly, and made it all look better than we even imagined."
Aaron F, Sherman Oaks
GreatBuildz Verified
Contractors
Every contractor in our network has passed our 10-point vetting process and signed our Code of Conduct. That's who shows up when we match you.
ADU FAQs for Los Angeles Homeowners
How much does an ADU cost in Los Angeles?
Most new-construction ADUs in Los Angeles cost $150,000 to $400,000, which works out to roughly $300 to $450 per square foot. A garage conversion ADU typically runs $120,000 to $150,000. On top of construction, budget $8,000 to $20,000 for building plans and $5,000 to $20,000 for plan check, permit, and city impact fees.
How long does it take to build an ADU?
A new-construction ADU typically takes 6 to 9 months from design through final inspection: 2 to 3 months for design and permits, then 3 to 6 months of construction. A garage conversion ADU usually takes 5 to 6 months total, because the structure and slab already exist.
How big of an ADU can I build in California?
Every California city has to allow an accessory dwelling unit of at least 800 square feet, and most properties can build up to 1,200 square feet. There is no minimum lot size, and your setbacks (the required gap between the building and your property line) are just 4 feet on the sides and rear.
Do I need a permit for an ADU in California?
Yes. Every ADU needs building permits, and your plans go through plan check with your city’s building department, which is LADBS in the City of Los Angeles. Approval is ministerial, meaning no planning board hearing and no neighbor sign-off, and your city has 60 days to approve or deny a complete application. Expect $5,000 to $20,000 in plan check, permit, and impact fees.
Do I have to pay city impact fees on an ADU?
An ADU of 750 square feet or less is exempt from city impact fees, and a junior ADU of 500 square feet or less is exempt as well. Larger ADUs are charged proportionally to the size of your main house. Plan check and permit fees still apply either way.
Does a junior ADU require me to live on the property?
Only when the junior ADU shares a bathroom with your main house. A JADU with its own bathroom carries no owner-occupancy requirement, so you can rent both units. A JADU is capped at 500 square feet and has to be built within the existing walls of your home.
Do I need to add a parking space for my ADU?
Not if your property sits within half a mile of public transit, which covers most of Los Angeles. Converting a garage into an ADU also does not trigger a requirement to rebuild the parking you lose.
Can my HOA stop me from building an ADU?
No. California law AB 670 prevents a homeowners association from banning accessory dwelling units on single-family lots. Your HOA can still enforce reasonable architectural standards like roof material or exterior color, so read your CC&Rs (the rules your HOA operates under) before you finalize a design.
Can I legalize a garage conversion that was built without permits?
Often, yes. California law lets homeowners legalize an unpermitted ADU or garage conversion built before January 1, 2020 through a health and safety checklist rather than a full code retrofit, with no penalties and no impact fees. Look for a contractor who has already taken one of these through your city.
How much can an ADU contractor ask for as a down payment?
California caps the deposit at $1,000 or 10 percent of the contract price, whichever is less. On a $250,000 ADU that means $1,000, not $25,000. A contractor asking for a large payment upfront is a serious red flag, and it is one of the things our vetting screens out.
Does an ADU add value to my home?
Usually. An ADU adds livable square footage and a second unit you can rent, and both show up in Los Angeles appraisals. How much value depends on your neighborhood, the quality of the build, and whether the unit has its own entrance, utilities, and outdoor space. For most homeowners the rental income is the more predictable return.
Finding an ADU Contractor in Los Angeles
Los Angeles has no shortage of contractors who say they build ADUs. The hard part is telling the ones who have actually permitted and finished an accessory dwelling unit in your city from the ones learning on your project. More than half of homeowners report a bad experience with a contractor, and an ADU is one of the largest projects a homeowner ever takes on.
That is why we started GreatBuildz. It is a free service that matches Los Angeles homeowners with pre-screened general contractors who build ADUs. Every contractor passes our 10-point vetting process before we invite them into the network: license, insurance, background check, references, financial review, and more. Contractors cannot pay to join, and only the ones who meet our standards get in.
LA County covers 88 cities, and ADU rules, plan check timelines, and fees shift from one to the next. Hillside lots, narrow older lots, and the half-mile transit parking exemption all change what fits on your property. We match you with three vetted contractors to compare, plus a remodeling advisor who helps you read the bids, and we stay involved through final inspection. If you want the numbers first, read our guide to ADU costs in Los Angeles, and if your garage is the plan, start with our garage conversion contractors page.
Using GreatBuildz costs you nothing, and we never sell your information. We match homeowners in Los Angeles and across California. Tell us about your ADU and we will connect you with the right contractor for it.
Hi, I’m Stephanie. I’ll match you with the right contractors for your project.