Fast, Reliable New Detached ADU Across Los Angeles
A new detached ADU in Los Angeles typically runs $220,000-$380,000 all-in for a custom build, or $180,000-$290,000 for a prefab or modular unit, with permit approval in 90-120 days under LA’s ministerial process. We design, permit, and build every New Detached ADU from our Los Angeles office, with crews serving the full metro from the Valley to the Eastside and South LA. Call (424) 344-4822 to schedule your free estimate, or bring us any written estimate already in hand for a free second opinion.
Why Ellery ADU Studio Torrance Is Los Angeles’s Preferred New Detached ADU Company
We’ve designed, permitted, and built over 900 ADUs since 2015, the year California’s ADU laws shifted. Every one carried a written price before work started, per Haven Standard Clause 1. Our Los Angeles clients receive the same documentation: a permit set treated as the core product, a photo record from every site visit, and the 365-Day Done Right Promise in writing before the first check clears.
Dispatch and scheduling run from our Los Angeles office, so Valley appointments don’t sit behind Orange County or San Diego queues. Crews know the difference between a 1962 slab-on-grade in Reseda and a 1920s pier-and-beam in Highland Park before they arrive. That local fluency means fewer surprises, and fewer surprises mean fewer change orders.
Live person answers calls 24/7. No voicemail queue. No callback that doesn’t materialize.
Our New Detached ADU Services in Los Angeles
Custom Built ADU
Custom builds are what most Los Angeles homeowners picture: stick-framed, designed to the lot, finished to match the main house. On a standard 50×130 R1 lot in Van Nuys or Reseda, we typically deliver a 749 sq ft one-bedroom with covered patio for $260,000-$380,000, drawings through final inspection. The price is written before we start, and any allowance - electrical panel upgrade, subfloor leveling, dry-rot repair - is listed as a line item with a ceiling, not a blank check.
Prefab ADU Installation
Prefab units from Cover or Boxabl arrive pre-finished and install in weeks, not months. In Los Angeles, where alley access on older lots lets us crane a module into the rear yard without disturbing the main house, prefab makes particular sense for homeowners who want rental income fast. A studio prefab in Los Angeles typically runs $180,000-$240,000 all-in, including foundation, utility tie-ins, and permit. We coordinate the manufacturer, the crane, and the city inspection as a single contract.
Modular ADU
Modular construction - Dvele and Mighty Buildings are the brands we specify most - builds sections in-factory under controlled conditions, then ships and assembles on-site. For Los Angeles hillside lots in Very High Fire Hazard Severity Zones, modular’s factory precision matters: Chapter 7A fire-resistant assemblies are built to spec in the plant, not interpreted by a framer on a slope in Studio City. Modular ADUs in Los Angeles range $200,000-$320,000 depending on fire-zone requirements and site access.
Studio ADU
The studio is Los Angeles’s rental workhorse: one open room, kitchenette, bath, 400-500 sq ft. At 749 sq ft or under, SB 13 wipes out impact fees entirely, so we engineer studios at the upper end of that range when the lot allows. A studio ADU in Los Angeles rents for $1,800-$2,800 depending on neighborhood, and builds for $220,000-$300,000 custom, or $180,000-$250,000 prefab. We quote the full number, not a shell price with finishes extra.
1-Bed & 2-Bed ADU
One-bedroom detached units dominate our Los Angeles portfolio: 600-749 sq ft, separate bedroom, full kitchen, covered patio for the outdoor living this climate demands. Two-bed units require more lot coverage and often trigger design review in hillside zones, but they’re viable on flat Valley lots with alley access. One-bed builds run $240,000-$340,000; two-bed units, $280,000-$420,000. Every quote includes the full permit set, not a design fee tacked on later.
What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in Los Angeles
We specify and coordinate prefab and modular systems from Cover, Dvele, Mighty Buildings, and Boxabl within the same single contract that covers your design, permit set, and construction. That means the manufacturer, the architect, and the builder share one written price and one point of accountability. In Los Angeles, where prefab lead times can stretch if the local foundation contractor and the factory aren’t talking, our single-contract model prevents the finger-pointing that kills timelines. We keep relationships active with each brand’s California distribution team, so Los Angeles clients don’t wait in a national queue.
Common New Detached ADU Problems We See in Los Angeles Homes
- Cloth-insulated or aluminum branch wiring in pre-1970s garages. Open a wall in a 1950s Van Nuys garage and you may find knob-and-tube or early Romex that won’t pass inspection. We inspect before quoting and write the panel upgrade into the contract as a line-item allowance, so the price doesn’t move when the electrician arrives.
- Out-of-level slabs or pier-and-beam subfloors. The 8-foot ceiling in a 1960s Reseda garage often hides a slab that settled or a pier-and-beam system that’s sagged. We measure before signing, price the leveling as an allowance, and if it’s worse than expected, we stop, document with photos, and get written approval before cutting.
- Chapter 7A fire-resistant construction on hillside lots. Properties in Very High Fire Hazard Severity Zones - Studio City, Topanga, Sunland-Tujunga, parts of Eagle Rock - need Class A roofing, ember-resistant vents, and ignition-resistant siding. A flatland bid on a hillside lot is a budget disaster waiting to happen. We verify the fire zone before the first drawing.
- Dry-rotted sill plates and failed waterproofing. Decades of Los Angeles winter rains and summer heat cycling will rot the mudsill where the framing meets the slab. We find it during pre-construction inspection, price the repair, and write it into the scope. No door-side upsells, per Haven Standard Clause 5.
Pricing for New Detached ADU in Los Angeles, CA
| ADU Type | Typical Range (Los Angeles) | What Drives the Top of Range |
|---|---|---|
| Studio prefab (Cover, Boxabl) | $180,000-$250,000 | Foundation conditions, utility distance |
| Studio custom build | $220,000-$300,000 | Finish level, covered patio, fire zone |
| 1-bed custom or modular | $240,000-$340,000 | Chapter 7A requirements, slab work |
| 2-bed custom | $280,000-$420,000 | Lot coverage, design review, parking |
| Electrical panel upgrade (allowance) | $4,000-$8,000 | Service size, trenching, overhead/underground |
| Subfloor leveling or slab repair (allowance) | $3,000-$12,000 | Extent of settlement, pier-and-beam vs. slab |
| Chapter 7A fire-resistant package | $20,000-$40,000 | Roofing, vents, siding, decking assemblies |
These ranges are what we actually quote in Los Angeles. Every project gets a written price before any work starts, per Haven Standard Clause 1. No “call for pricing.” No shell bids with finishes extra. Call (424) 344-4822 for your free estimate, or bring us a written estimate from another firm for a free second opinion.
We Also Serve Cities Near Los Angeles
Our crews work throughout the metro, including Los Angeles proper and the immediate surrounding cities: South Gate, Lynwood, Gardena, and Inglewood. Each shares LA’s R1 zoning patterns, alley-accessed lots, and the same SB 13 impact-fee structure, so pricing and permitting timelines hold consistent across the service area.
Serving Los Angeles, CA - Our Local Coverage Area
We’re based in the Los Angeles area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs - New Detached ADU in Los Angeles
Yes. California SB 13 prohibits Los Angeles and every other California jurisdiction from charging impact fees on any ADU under 750 square feet. That makes 749 sq ft the de facto standard floorplan across the Valley and most of the city, and any contractor who doesn’t know that number cold will consistently lose bids to competitors who do. We engineer at 749 sq ft as our default one-bedroom layout unless the client explicitly wants larger and accepts the fee impact. Call (424) 344-4822 to see how this applies to your lot.
Yes, and it’s the dominant ADU type in those neighborhoods. The postwar stucco-and-frame detached garage on a 50×130 R1 lot, with alley access and an existing slab, converts faster and cheaper than ground-up construction in almost any comparable U.S. city. We inspect the slab, ceiling height, electrical service, and framing before quoting, then write any needed upgrades as line-item allowances. Call (424) 344-4822 to schedule that inspection.
On a 50×130 R1 lot off Van Nuys Boulevard in Van Nuys, we tore into a 1961 stucco-and-frame detached garage and found the slab was fine but the 8-foot ceiling hid knob-and-tube wiring and a sub-100-amp panel feeding the main house. We inspected before signing anything, wrote a full electrical panel upgrade and subfloor leveling into the contract as line-item allowances, and when the framer uncovered dry-rotted sill plates we priced the repair and got written approval before removing a single board. The finished detached ADU is now a 749 sq ft one-bed with a covered patio and a fully separate alley address. That’s our standard process: inspect first, document with photos, write allowances into the contract, and price any surprise in writing before we touch it.
If your property sits in a Very High Fire Hazard Severity Zone - the Santa Monica Mountains, Topanga, Studio City hills, Sunland-Tujunga, parts of Eagle Rock - then yes, California Building Code Chapter 7A applies. That means Class A roofing, ember-resistant vents, and ignition-resistant siding, typically adding $20,000-$40,000 over a flatland build. We verify the fire zone in our first site visit and quote that package upfront, not as a surprise mid-project. Call (424) 344-4822 to check your property’s zone status.
We don’t wait for walls to open. Our pre-construction inspection identifies the likely triggers - outdated wiring, undersized panels, out-of-level slabs, dry rot - and writes each as a line-item allowance with a price ceiling. If the condition is worse than expected, we stop work, photograph the finding, price the repair, and get written approval before proceeding. Under Haven Standard Clause 5 (No Surprises), the scope is locked at signing; any new condition is documented, priced, and approved in writing. No door-side upsells. No scope creep. Call (424) 344-4822 to walk through how this works on your specific property.
Written by Nadia Ellery, Owner at Ellery ADU Studio, serving Los Angeles since 2015.