How Much Does a New Detached ADU Cost in Los Angeles?
A new detached ADU in Los Angeles typically costs between $180,000 and $420,000 as of 2026, with most homeowners landing somewhere around $240,000 to $320,000 for a permitted 600 to 800 square foot unit. That range covers design, permits, foundation, framing, utilities, finishes, and site work on a standard residential lot. The low end reflects a simple prefab build on an easy lot; the high end covers custom construction on a hillside with long utility runs.
If you’re looking at that number and thinking it’s a wide spread, you’re right. A detached ADU is a small house. Price moves hard based on slope, utility distance, and finish level. We’re Lodgewick ADU Builders, the ADU company of the Kingswell family, and we’ve been building accessory dwelling units, garage conversions, and home additions since 2010. Below, we put real numbers on the page so you don’t have to call just to get a ballpark.
One thing before the numbers: we give you a written price before any work starts, every single time. That price doesn’t change at the door. It’s part of The Kingswell Guarantee, and it’s in writing on every project.
Quick Answer: What Will a Detached ADU Actually Run Me in Los Angeles?
Budget $250 to $450 per square foot for a new detached ADU in Los Angeles. A 600 sq ft one-bedroom unit usually runs $165,000 to $245,000. An 800 sq ft two-bedroom unit typically runs $215,000 to $330,000. Add $15,000 to $60,000 or more if your lot has a steep grade, a long utility trench, or requires zoning variances.
Those are fully built, permitted, move-in-ready numbers. Not shell costs. Not “plus finishes.” A complete number you can take to a lender.
Key Takeaways
- Typical Los Angeles detached ADU: $250 to $450 per sq ft
- 600 sq ft one-bedroom: $165,000 to $245,000
- 800 sq ft two-bedroom: $215,000 to $330,000
- Prefab units (Abodu, Cover, Dvele, Mighty Buildings, Boxabl, Plant Prefab) often reduce time and cost versus full custom
- We provide a written price before work begins, always, under The Kingswell Guarantee
- Free estimates: call (254) 602-5618 and a live person answers, 24/7
New Detached ADU Cost Breakdown (Los Angeles, 2026)
Here’s how a typical 700 sq ft detached ADU in Los Angeles breaks down line by line. These are real market ranges for the city, not national averages.
| Line Item | Typical Range (Los Angeles) | Notes |
|---|---|---|
| Design, architecture & engineering | $12,000 – $35,000 | Title 24 energy calcs, structural, and site survey included |
| Permits, plan check & LADBS fees | $8,000 – $22,000 | School fees, DWP electrical/water connections, sewer impact |
| Site prep, demo & grading | $10,000 – $45,000 | Higher on hillside lots in Echo Park, Silver Lake, Mt. Washington |
| Foundation | $18,000 – $42,000 | Slab for flat lots; piers or caissons on slopes |
| Framing & structural | $35,000 – $70,000 | Material costs climbed again in early 2026 |
| Roofing | $9,000 – $22,000 | Standing seam metal or architectural shingle |
| Windows & exterior doors | $8,000 – $24,000 | Title 24 glazing requirements apply |
| Electrical, plumbing & HVAC | $28,000 – $65,000 | Includes trenching to main panel and sewer tie-in |
| Insulation, drywall & paint | $14,000 – $30,000 | Interior and exterior |
| Flooring, cabinets & countertops | $12,000 – $38,000 | Where finish level swings cost the most |
| Kitchen & bathroom fixtures | $9,000 – $26,000 | Appliances, tile, plumbing trim |
| Landscaping & hardscape repair | $5,000 – $20,000 | Restoring yard after construction access |
Add those line items up on a typical 700 sq ft build and you land between $210,000 and $310,000. What pushes you toward the top of that range? Long utility runs to the back of a deep lot, a hillside grade, a panel upgrade to 200 amps, and premium finishes. What pulls you toward the bottom? A flat lot near the street, standard finishes, and a prefab unit from a manufacturer like Abodu or Cover that arrives mostly assembled.
If you want to dig into the build process itself, our New Detached ADU in Los Angeles page walks the whole project from first walkthrough to final inspection. And you can start from our home page to see everything we do.
What Affects Detached ADU Pricing in Los Angeles
Los Angeles has its own cost drivers. They don’t look like the drivers in a flat mid-size city, and they don’t look like the ones in San Diego or San Jose either. Here’s what actually moves the number here.
- Slope and lot topography. Flat lots in Woodland Hills or Northridge build for standard foundation costs. Hillside lots in Echo Park, Silver Lake, and Mt. Washington need caissons, retaining walls, and often a structural engineer’s site-specific plan. That alone can add $30,000 to $60,000.
- Distance from the main house and main panel. A detached ADU at the back of a 150-foot lot needs a trench for electrical, water, gas, and sewer. Trenching in Los Angeles runs $50 to $120 per linear foot depending on soil and what’s underground. Deep lots in Sherman Oaks and Encino are the usual culprits.
- LADBS permitting and review time. Los Angeles Department of Building and Safety plan check can take 4 to 12 weeks depending on the plan. This adds soft cost and schedule, and it’s why prefab plans that have been pre-approved tend to move faster.
- Utility connections and DWP coordination. A new DWP electrical service and water hookup, plus sewer capacity review, adds hard cost. In older parts of Highland Park and Boyle Heights, an aging sewer lateral is often discovered and must be replaced.
- Finish level. A basic kitchen and LVP flooring versus custom cabinetry and quartz counters is a $25,000 swing on its own. We match the finish to how you’ll actually use it: rental, family, or aging parents.
- Prefab versus site-built. A prefab unit from Dvele, Mighty Buildings, or Boxabl can cut build time by months and, on a straightforward lot, save $20,000 to $50,000 versus full custom. We work with Abodu, Cover, Dvele, Mighty Buildings, Boxabl, Plant Prefab, Tuff Shed, and James Hardie and match the right one to your lot and budget.
California and Los Angeles rules that affect your cost
California state law now allows an ADU up to 1,200 sq ft in most single-family zones, and state law limits what cities can charge in impact fees. Los Angeles has its own overlay standards and design review in certain areas, including hillside communities and HPOZ (Historic Preservation Overlay Zone) neighborhoods like Angelino Heights and parts of Highland Park. HPOZ review adds time and sometimes adds cost, because exterior materials and window styles must match the historic character. We plan for that before we submit, not after.
The good news: state law also tells LADBS to approve or deny your ADU permit within a defined window, and it limits the reasons a city can reject a compliant ADU. That means fewer surprises than a homeowner might expect. Our job is to submit a plan that clears on the first pass.
How Much Does a Detached ADU Cost Per Square Foot in Los Angeles?
Los Angeles detached ADUs land between $250 and $450 per square foot fully built and permitted. Under $250 per sq ft usually means a simple prefab on a flat lot with standard finishes. Over $450 per sq ft means hillside engineering, custom design, and high-end finishes.
Two projects the same size on the same street can land $80,000 apart. The difference is almost always the lot and the finish, not the square footage. That’s why we walk the property before we quote. A written price based on a real lot beats a per-square-foot guess every time.
Prefab vs. site-built cost in Los Angeles
Prefab ADUs from manufacturers like Abodu, Cover, Dvele, Mighty Buildings, or Boxabl arrive as a kit or module. Site work, foundation, utility connections, and finishing still happen on your lot in Los Angeles, and those costs don’t disappear. What prefab saves is time: often 2 to 4 months off the schedule, which matters if you’re losing rent or waiting to move someone in. Site-built gives you more freedom on layout, ceiling height, and how the unit sits on a tough lot.
We build both. We’ll tell you honestly which fits your lot, your budget, and your timeline. That’s The Kingswell Way: say the price before the work, show up in the window we give, and put the guarantee in writing.
How to Save on a New Detached ADU in Los Angeles
You can’t build a detached ADU in Los Angeles cheaply, and anyone promising that is either cutting corners or hiding fees. But you can keep the number down with a few decisions we see work again and again.
- Build prefab where the lot allows it. On a flat or gently sloped lot near the street, a prefab unit from Plant Prefab or Mighty Buildings can save $20,000 to $50,000 versus full custom.
- Keep the unit closer to the main house and main service. Shorter trench runs save real money. If your lot layout gives you a choice, put the ADU where the utilities already live.
- Right-size the unit. A 600 sq ft one-bedroom at $250 per sq ft is $150,000. An 800 sq ft two-bedroom at $300 per sq ft is $240,000. Only build the square footage you’ll use.
- Choose pre-approved or standard plans. LADBS pre-approved ADU plans and standard plan review can trim plan check time and cost.
- Don’t over-finish a rental. If the unit is for rental income, standard finishes rent just as well as premium ones. Save the custom cabinetry for a family ADU.
- Do the work in one pass. If your main panel needs an upgrade or the sewer lateral is failing, handle it during the ADU build. Redoing it later costs more.
Our estimates are free, and a live person answers every call, day or night at (254) 602-5618. No voicemail loop. No chatbot. You get a written price before any work starts, and that price holds under The Kingswell Guarantee.
Is Detached ADU Construction Priced the Same Across Los Angeles Neighborhoods?
No. The citywide range is $250 to $450 per sq ft, but your actual neighborhood shifts where you land. In the San Fernando Valley, flat lots in Woodland Hills, Northridge, and Canoga Park tend to build toward the lower end, often $250 to $330 per sq ft, because the ground is flat and utilities run short. In hilly areas like Echo Park, Silver Lake, and Mt. Washington, slope and retaining work push toward the high end, often $350 to $450 per sq ft. In HPOZ zones like Angelino Heights and Highland Park, exterior material and window requirements add cost and review time.
Two neighborhoods five miles apart can differ by $60,000 on the same 700 sq ft unit. That’s why we walk your lot before we give you a number.
What Does the 365-Day Done Right Promise Cover on an ADU Build?
If something we installed fails within 365 days, we come back and make it right at no charge. That includes electrical, plumbing, HVAC, and anything else tied to our work on your ADU. The commitment is in writing on every project, delivered before a single nail is driven. It’s a free return visit, not a bill.
Most ADU problems show up in the first year: a settling door that won’t latch, a small leak at a fixture, a breaker that trips. Those are exactly the calls homeowners say they fear from their last contractor. Our answer is simple. We come back in the window we give you, do the work, and leave the site cleaner than we found it. That’s not a slogan. It’s what The Kingswell Guarantee says in writing.
FAQs – Detached ADU Cost in Los Angeles
How much does a detached ADU cost in Los Angeles?
A fully built and permitted detached ADU in Los Angeles costs between $180,000 and $420,000 as of 2026, with most homeowners spending $240,000 to $320,000. That’s roughly $250 to $450 per square foot. Call (254) 602-5618 for a free estimate on your specific lot; you’ll get a written price, and it holds.
Is it cheaper to convert a garage or build a new detached ADU?
A garage conversion typically costs $75,000 to $180,000 in Los Angeles, while a new detached ADU runs $180,000 to $420,000. So yes, a garage conversion is cheaper. But a detached unit gives you more square footage, an independent structure, and usually a higher rental value. Which one makes sense depends on your lot and how you’ll use the space. Call (254) 602-5618 and we’ll walk you through both numbers side by side.
How much does an 800 square foot ADU cost in Los Angeles?
An 800 sq ft two-bedroom detached ADU in Los Angeles typically costs $215,000 to $330,000 fully built and permitted. That assumes a flat or gently sloped lot with standard-to-mid finishes. A hillside lot or long utility run can push the same unit past $360,000. Free estimates at (254) 602-5618.
Are ADU permits expensive in Los Angeles?
Permits, plan check, and LADBS fees for a detached ADU in Los Angeles typically run $8,000 to $22,000, including school fees and DWP electrical and water connections. California law limits certain ADU impact fees, and we build those fees into the written price upfront so there’s no surprise later. Call (254) 602-5618 for an exact fee breakdown for your lot.
How long does it take to build a detached ADU in Los Angeles?
A detached ADU in Los Angeles usually takes 6 to 12 months from first design meeting to final inspection. Plan check alone can take 4 to 12 weeks, and construction runs 3 to 6 months for a site-built unit or 1 to 3 months once a prefab module arrives. Call (254) 602-5618 and we’ll give you a written schedule with your written price.
Is it cheaper to repair or replace on an ADU build?
If you already have a converted garage or an older structure on your lot, repairing it usually costs less than building new, but only if the foundation, framing, and utilities are sound. In Los Angeles, older backyard structures in Boyle Heights, Highland Park, and South LA often have framing that won’t pass current code. When that’s the case, replacement is the better value. We inspect first, then tell you which one the numbers support. Call (254) 602-5618 for a free assessment.
Why Homeowners Choose Lodgewick ADU Builders for Los Angeles ADUs
Lodgewick ADU Builders is the ADU company of the Kingswell family, established in 2010. We’ve worked with the leading prefab manufacturers and materials suppliers in the ADU space, including Abodu, Cover, Dvele, Mighty Buildings, Boxabl, Plant Prefab, Tuff Shed, and James Hardie, so we can match the right build method to your lot instead of forcing one approach on every project.
The name comes from an old idea: a lodge is a small house on a larger property. That’s exactly what an ADU is. Every project we take on runs on The Kingswell Way, which is the way crews behave: say the price before the work, show up in the window we gave you, leave the place cleaner than we found it, put the guarantee in writing, and come back if something fails.
That’s backed by the 365-Day Done Right Promise, a written guarantee on every project, and a free return visit if the work fails within the guarantee period. Our technicians are background-checked and uniformed, so you always know who’s on your property. And every call is answered by a live person, 24 hours a day, seven days a week. Not a voicemail, not a chatbot. Each Lodgewick location is independently owned and operated under The Kingswell Guarantee.
Get Your Written ADU Price for Your Los Angeles Lot
You shouldn’t have to call a contractor just to get a ballpark. That’s why we put real dollar ranges on this page. But every Los Angeles lot is different, and the only number that matters is the one for your property. Call (254) 602-5618 for a free estimate. We’ll walk the lot, talk through prefab versus site-built, and hand you a written price before any work starts. A live person answers, day or night, and the price we write down is the price you pay, guaranteed under The Kingswell Guarantee.
Related reading
Written by Russ Delmar, Owner at Lodgewick ADU Builders, serving Los Angeles since 2010.
Pricing reflects the Los Angeles market as of 2026. Lodgewick ADU Builders offers free estimates – call (254) 602-5618.
What Our Customers Say
"I was nervous about adding on but they walked me through every step and every cost before we started. No surprise change orders halfway through like I'd heard horror stories about."
- Eleanor Pratt"Junior ADU conversion inside the house. They protected the rest of our place with plastic and daily cleanup. Done nearly on schedule and on the number they quoted."
- Sabrina Veld"Garage conversion into an office and guest room. Fair written price, finished close to on schedule, and they fixed a small drywall crack under warranty months later without any hassle."
- Diana Cho