Detached ADU Construction in Los Angeles
A Whole Second Home. One Backyard.
A brand-new standalone home in your backyard — full kitchen, full bath, its own front door and its own address.
What A Detached ADU Construction Actually Is
A detached ADU is a complete second home built from the ground up on your lot: its own foundation, its own walls, its own front door. Nothing is carved out of your existing house, so the main home keeps every square foot — and the unit gets real privacy, the kind tenants and family both pay for.
It's the most expensive ADU type and the most flexible. Because we're building new, we can place it to fit your yard, orient windows for light, and size it anywhere from a studio to a full two-story two-bedroom.
Up to 1,200 sq ft
State law guarantees at least 800 sq ft, and LA generally allows up to 1,200 sq ft for a detached unit, subject to lot coverage and setbacks.
4 ft setbacks
Detached units need 4 ft side and rear setbacks — we plan the footprint around what your lot allows.
Its own address
A permitted unit with its own final inspection and certificate — never a gray-area conversion.
Separate metering available
So the tenant pays their own power. We price both options and check your panel either way.
What Drives The Number
Detached builds are the biggest investment of the ADU types — you're paying for a full structure from the footing up. Real ranges from recent LA jobs; your exact number comes from a site visit.
Detached 1-Bedroom ADU
$230K–$390K
600–800 sq ft built new from the footing up. Full kitchen, full bath, laundry, mini-split, private entry and patio.
Detached 2-Bed / Two-Story
$390K–$600K+
900–1,200 sq ft, or two stories on a tight lot. Adds a staircase, shear walls and heavier structural engineering — and the highest rent per lot.
- Size and story count — every extra story adds structure, stairs and engineering
- Slope — hillside lots can need caissons or a stepped foundation, plus slope-band height limits and fire access
- Utilities — panel capacity and the sewer lateral are the two most common surprise costs, so we check both before design
- Site access — a tight alley or a crane day changes the number
- Finish level — where your kitchen and bath spec lands
What Will Your ADU Cost?
Pick your type, size and finish level and see a real Los Angeles range in seconds. No email gate — the estimate is right there. Your exact number still comes from a site visit.
01 — Type of build
Two-story units add a staircase, shear walls and heavier engineering — real money beyond the square footage alone.
02 — Square footage
03 — Bedrooms
Bathrooms
04 — Finish level
$230K – $280K
Build range for a 500 sq ft new detached adu at mid-range finish, excluding architectural and engineering plans and city permit fees.
- Architectural & engineering plans — not included in the estimate above
- $6,500 – $15,000
- City permit fees — not included in the estimate above
- Varies by city
- Est. monthly payment
- ~$2,225/mo
- Typical LA rent
- ~$2,550/mo
Architectural and engineering plans are not included in project prices or cost estimates. ADU plans typically cost $6,500–$15,000 and are quoted separately according to each project's size, specifications, requirements and difficulty.
City permit fees are not included in project prices or cost estimates. They are separate costs based on what the city charges for your project. WOW processes all permits for every project so clients don't have to worry, and we provide the city fee receipts for their control.
Payment assumes a 20-year loan around 8.5% APR on the build midpoint, excluding architectural and engineering plans and permit fees. Rent is a neighborhood average, not a guarantee — some LA pockets run well above it, some below.
Ranges come from recent Los Angeles builds. Slab condition, sewer distance and panel capacity are the three things that move the number — we check all three on the free site visit.
How Long It Takes
Design & permits
3–5 months. Full architectural set, plan check, corrections and utility clearances — we stand in the line, you get updates.
Build
4–7 months on site. Foundation, framing, MEP rough, inspections, insulation, drywall, finishes.
Start to keys
Call it 8–12 months — final sign-off, address assignment and the warranty package.
Permits, Handled
City permit fees are not included in project prices or cost estimates. They are separate costs based on what the city charges for your project. WOW processes all permits for every project so clients don't have to worry, and we provide the city fee receipts for their control.
- Site plan, floor plans, elevations, Title 24 and structural — the full permit package
- Plan check submittal, corrections and utility clearances handled by us
- Permit processing, plan check management and engineering are in our scope
- City, utility and school fees are billed at cost, so you see what LA actually charges
Real Work, Real LA Homes
Not stock art. Actual projects our crews have delivered across Los Angeles.
