ADU contractors / Los Angeles County
ADU Contractors, Los Angeles: what actually fits on your lot.
Building an ADU in Los Angeles starts with one question: what does your parcel actually allow? Send us the address and nothing else. Within 48 hours you get the maximum ADU size your parcel allows, which type suits it, and a realistic cost band. No site visit, no sales call, no obligation.
Detached, attached, garage conversion, JADU and prefab.
LADBS plan check handled end to end / Fixed price off the permitted set /
Payments tied to passed inspections
Detached ADU, 780 sq ft, set four feet off the side and rear property lines. This is what fits on the majority of Los Angeles lots.
- Licensed & bonded
- CSLB 1117837HCD #DL1611393, verify at cslb.ca.gov
- Custom ADU timeline
- 8 to 10 moNine signature site-built styles
- Prefab ADUs from
- $115,000Delivered fully assembled
- Profit to housing
- 10%Of all profits go to housing the homeless
Six ways to add a unit
ADU builders in Los Angeles for every lot condition
Which one is right depends on your lot geometry, your existing structures and what you want the unit to do. Every page below carries the real cost band, the size limit and the timeline, not a brochure version of it.
Detached ADU
Typical 750 sq ft detached unit: $300,000 to $450,000 all-in, by style
Garage conversionGarage Conversion
Conversion pricing depends on slab, height and utilities. Quoted from the site visit.
AttachedAttached ADU
Typical 600 sq ft attached unit: $240,000 to $360,000 all-in
JADUJunior ADU (JADU)
JADU cost is driven by the existing plumbing wall and egress. Quoted from the site visit.
Ground-upGround-Up Construction
Traditional style at the low end, Modern at the high end
Floor plansADU Floor Plans
Standard plan sets save roughly $6,000 and 6 weeks of plan check
PrefabPrefab / Modular ADU
Nest 200 sq ft $115k / Nest One 500 sq ft $263k / Nest Two 638 sq ft $317k
Design & permitsDesign & Permits
Design, engineering and city fees for a typical detached unit
FinancingFinancing & Returns
Most LA clients fund with a renovation loan or a HELOC
CasitaCasita / Granny Flat
Typical 600 sq ft casita: $240,000 to $360,000 all-in
Two-storyTwo-Story ADU
Typical 1,000 sq ft two-story unit: $450,000 to $650,000 all-in
Above garageADU Above Garage
Typical 550 sq ft unit over a 2-car garage: $250,000 to $360,000 all-in
LegalizationUnpermitted ADU Legalization
Legalization cost depends entirely on what has to be opened up. Quoted after inspection.
MultifamilyMultifamily ADU
New detached units. Conversions of existing non-habitable space price lower.
Where the money goes
What an ADU costs in Los Angeles, without the vagueness
Prefab units start at $115,000 for the 200 sq ft Nest. Custom site-built runs $400 per square foot for Traditional up to $600 for Modern. Conversions are priced after a site assessment, because the slab, the ceiling height and the utilities decide the number. The four things that quietly blow LA budgets are the electrical service upgrade, the sewer lateral, the soil report and site access, and all four can be checked before you sign anything.
How a project runs
Six stages, and you only have to make decisions in two of them
The order matters here, which is why it is numbered. You approve the design and you approve the finishes. We handle the parcel research, the plan check corrections, the subcontractor sequence and every inspection.
Lot check
48 hours, free
You send the address. We pull the parcel, the zoning, the setbacks and the overlays, and tell you what size ADU actually fits and what it will roughly cost. No site visit needed and no obligation.
Site visit and feasibility
Week 1
We walk the lot, find the sewer lateral and the electrical service, check crane and equipment access, and confirm ceiling heights on any structure you want to convert. You get a written feasibility report.
Design and engineering
Weeks 2 to 6
Full architectural set, structural calculations, Title 24 energy compliance. You approve the layout and the elevations before anything is filed. This is where changes are cheap.
LADBS plan check
Months 2 to 5
We file, we track, and we clear every correction cycle. You do not talk to a plan checker. Expect four to eight weeks for the first response and one to two correction cycles after it.
Construction
Months 5 to 11
Eight inspected stages from footing to final. One superintendent on site daily, a weekly photo log, and a written schedule update every Friday. Payments are tied to passed inspections, not calendar dates.
Final sign-off and handover
Closing week
Certificate of occupancy, a separate mailing address, all warranty documentation, appliance manuals and the as-built set. If you are renting it, we hand over photos sized for the listing.
Service area
Where we build across Los Angeles County
Every jurisdiction here permits differently. Pasadena, Glendale, Burbank, Santa Monica, Long Beach and Torrance all run their own building departments rather than LADBS, and the local overlays change what is buildable.
On the map
ADU builders in Los Angeles, working across the county
From the Valley flats to the South Bay. Every jurisdiction on this map permits differently, and we run projects through all of them: LADBS in the city, and the independent building departments in Pasadena, Glendale, Burbank, Santa Monica, Long Beach and Torrance. If you got here searching for ADU builders near me, this map is the honest answer to what "near" covers.
Guides
Costs, laws and timelines, explained properly
ADU Cost in Los Angeles: What It Actually Runs in 2026
Prefab starts at $115,000. Custom site-built runs $400 to $600 per sq ft depending on style. Here is where every dollar goes, and the four line items that wreck budgets in LA.
RulesCalifornia ADU Laws and What They Mean in Los Angeles
California ADU laws override most local restrictions. Here is what Los Angeles must allow, what it can still regulate, and where homeowners get told no when the answer is legally yes.
RulesSB 9 in California: Lot Splits and How They Compare to an ADU
SB 9 lets you split an urban single-family lot in two and put two units on each half. It is not an ADU, the restrictions are heavier, and for most LA homeowners the ADU is still the better move. Here is how to tell.
Questions
ADU questions Los Angeles homeowners actually ask
What is the cheapest way to add an ADU in Los Angeles?
Converting an existing garage. The shell, slab and roof already exist, so you pay for utilities, insulation, windows and finishes rather than a whole new structure. Prefab is the next cheapest at $115,000 for the 200 sq ft Nest. A custom detached build costs the most and returns the most.
How soon can construction actually start?
Design and engineering take four to six weeks, then LADBS plan check runs two to five months depending on correction cycles. Realistically the first footing goes in around month five. Using an LADBS pre-approved standard plan removes roughly six weeks from that.
What would stop an ADU from working on my lot?
Rarely the zoning, usually the physical lot. Slope, a protected tree, fire department access width, an undersized electrical service or a sewer lateral in the wrong place are the real blockers. All five get checked during the free 48-hour lot check before you spend anything.
Will I lose my driveway or garage space?
Not for a garage conversion, since the city cannot ask you to replace parking you convert. For a new detached unit, most Los Angeles parcels sit within half a mile of a transit stop and are exempt from adding parking at all. Your driveway stays as it is.
Free 48-hour lot check
Send the address. We do the parcel research and tell you what fits.
Your lot either takes an ADU or it does not. Find out for free.
We pull the zoning, setbacks and overlays and give you a straight answer within 48 hours. There is no site visit and no obligation.