Fast, Reliable New Detached ADU Across Los Angeles
A new detached ADU in Los Angeles typically runs $220,000-$420,000 all-in, from permit set through final inspection, depending on whether you’re building on a flatland lot with standard LADBS approval or navigating hillside WUI requirements. Most of our Los Angeles clients are converting a detached one-car garage on a 1920s-1950s bungalow lot, which means the project is less “clean sheet design” and more “discover what’s actually under the slab, then price it in writing.” We coordinate dispatch and scheduling from our Los Angeles office, and our crews serve the full basin from West Adams to the eastern San Fernando Valley. Call (213) 329-7167 to schedule your free estimate - every project starts with a written price before any work begins, per Haven Standard, Clause 1.
Why Ellery ADU Studio West Hollywood Is Los Angeles’s Preferred New Detached ADU Company
We’ve designed, permitted, and built more than 900 ADUs since 2015, the year California’s ADU laws shifted, and Los Angeles has consistently been our highest-volume market. That volume matters because LADBS processes more ADU permits than any other California jurisdiction, and the specific way the city layers its local ordinance on state law creates shortcuts - and traps - that only show up after you’ve been through the cycle a few hundred times.
Our Los Angeles clients receive a documented photo record on every site visit, not a summary of how the visit felt. Under Clause 5 of The Haven Standard, the scope is locked at signing; no door-side upsells, no scope creep. If the finished ADU is not built to the permitted drawings, our 365-Day Done Right Promise applies - in writing, before the project starts.
A live person answers calls 24/7. No voicemail queue, no callback promise that doesn’t materialize.
We also offer a Free Second Opinion on any written estimate already in hand. Bring us another contractor’s scope and we’ll flag what’s missing, what’s overstated, and what Los Angeles-specific conditions they likely haven’t priced.
Our New Detached ADU Services in Los Angeles
Custom Built ADU
Custom built ADUs in Los Angeles are our core work, especially on the flatland lots that dominate West Adams, Mid-City, and Leimert Park. These 5,000-7,500 sq ft parcels almost always hold a detached one-car garage on pier-and-beam with no seismic ties, uninsulated stud walls, and original knob-and-tube or early Romex. The moment LADBS pulls the permit, that existing structure must be brought up to current lateral-bracing and foundation standards - a scope item that doesn’t exist on a new slab-on-grade ADU in most other California markets. We probe footings and open walls before we sign a fixed number, photograph every condition, and price structural and electrical upgrades as written allowances with owner sign-off before a single form is set.
Prefab ADU Installation
Los Angeles’s LADBS Standard Plan Program includes pre-approved prefab and modular designs that can bypass standard plan check entirely, compressing permitting from six-plus months to weeks. But there’s a catch: the city’s pre-approved plans are sized and sited to a “typical” lot. Hillside parcels, lots with Alquist-Priolo earthquake fault setbacks, or parcels in a designated liquefaction zone immediately fall out of that fast-track pathway and revert to full discretionary review. We specify and coordinate prefab systems from Abodu, Cover, and other manufacturers within our single-contract model, and we verify lot eligibility for the Standard Plan Program before we quote - not after you’ve paid a deposit.
Modular ADU
Modular ADUs in Los Angeles make sense when the lot is straightforward and speed matters. We work with Dvele and other modular brands to deliver units that arrive 80-90% complete, then handle the site prep, foundation, utility tie-ins, and LADBS inspections under the same contract. On flatland lots with standard soil conditions and no fault or liquefaction issues, modular can cut two to three months off the build timeline. We disclose where modular saves time and where it doesn’t: foundation work, utility trenching to the main house, and any required seismic retrofit of the existing structure still happen on site, and we price those line items separately in writing.
Studio ADU
Studio ADUs are the most common detached unit we permit in Los Angeles, typically 350-450 square feet on a converted garage footprint. The LADBS Standard Plan Program offers several pre-approved studio designs that work well on the 5,000 sq ft bungalow lots common in Boyle Heights and the eastern San Fernando Valley. We price studio ADUs from $220,000-$310,000 all-in for flatland sites with standard utility access, with written allowances for foundation and electrical upgrades triggered once we probe the existing structure. Every studio project includes the full permit set as our core deliverable, not an afterthought.
1-Bed & 2-Bed ADU
One-bedroom and two-bedroom detached ADUs in Los Angeles typically require a larger footprint than the standard one-car garage conversion, often combining garage demolition with a portion of the rear yard. LADBS allows detached ADUs up to 1,200 square feet on most residential lots, and our 1-bed units typically run 500-650 square feet while 2-bed units land at 750-950 square feet. On hillside parcels in the Hollywood Hills or Laurel Canyon, these larger footprints trigger additional WUI construction requirements - Class A roofing, fire-resistant siding, ember-resistant vents - that can add $35,000-$65,000 to the base build. We identify WUI zones during our initial site survey and price the full requirement in writing before you sign.
What happens when you call
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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.
Before
AfterTrusted Brands We Service in Los Angeles
We specify and coordinate prefab and modular systems from Abodu, Cover, Dvele, Mighty Buildings, Boxabl, Plant Prefab, Tuff Shed, and James Hardie within our single-contract design-build model. For Los Angeles clients, this means we source James Hardie fiber-cement siding and other fire-resistant cladding materials that satisfy both LADBS structural requirements and WUI construction standards for hillside parcels. We don’t hand you off to a separate installer after the box arrives. Our crews handle specification, delivery coordination, foundation integration, utility tie-in, and final inspection - one contract, one written price, one point of accountability if something doesn’t match the drawings.
Common New Detached ADU Problems We See in Los Angeles Homes
- Seismic and foundation failures on flatland garage conversions. The detached one-car garage sitting behind that 1928 Spanish Colonial Revival in West Adams? Probably pier-and-beam with zero seismic ties and a stem wall that’s settled four inches. LADBS requires current lateral-bracing and foundation standards the moment the ADU permit is pulled. We photograph every condition and price the upgrade as a written allowance before work starts.
- Knob-and-tube and early Romex triggering full rewires. Original electrical in 1920s-1950s Los Angeles bungalows was never designed for a second dwelling unit. We find ungrounded circuits, overloaded subpanels, and active knob-and-tube feeding garage lights. Our techs test every circuit during the initial probe and price a full rewire from the meter if needed - documented, approved, then executed.
- WUI construction requirements on hillside lots. Parcels in the Very High Fire Hazard Severity Zone - Hollywood Hills, Laurel Canyon, the Santa Monica Mountains - require Class A roofing, fire-resistant siding, and ember-resistant vents that flatland builds don’t. Contractors who price off a standard plan without checking the city’s fire hazard map leave clients with surprise five-figure upgrades mid-build. We pull the hazard designation before we quote.
- Standard Plan Program disqualifications. A lot that looks perfect for LADBS fast-track pre-approval can revert to full discretionary review if it touches a liquefaction zone, an Alquist-Priolo fault setback, or a hillside grade exceeding program limits. We verify lot eligibility through LADBS records during our free estimate, not after you’ve committed to a timeline that doesn’t exist.
Pricing for New Detached ADU in Los Angeles, CA
A typical studio ADU on a flatland Los Angeles lot with standard LADBS approval runs $220,000-$310,000 all-in, drawings through final inspection. One-bedroom units typically land at $285,000-$380,000, and two-bedroom detached ADUs at $340,000-$420,000. Hillside parcels with WUI requirements add $35,000-$65,000 to any of those ranges. Foundation and electrical upgrades on converted garage structures - the seismic ties, stem wall repair, full rewire - typically add $18,000-$45,000 depending on what our probe reveals.
Every line item is priced in writing before you sign, per Haven Standard, Clause 1. No “call for a quote.” No range that balloons once work starts. If our probe finds conditions we couldn’t predict, we photograph them, price the fix, and get your written approval before we proceed. Call (213) 329-7167 for your free estimate - the written price follows the site visit, never the other way around.
We Also Serve Cities Near Los Angeles
Our New Detached ADU in Los Angeles crews also work in Inglewood, Culver City, West Hollywood, and Glendale. Each of these cities operates under its own ADU ordinance layered on California state law, with different plan-check timelines, fee schedules, and parking requirements. We maintain current permit knowledge for every jurisdiction we serve, and we quote each project against the actual local rules that will govern it.
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, but only if your lot matches the program’s assumptions: flat grade, standard 5,000+ sq ft lot, no hillside designation, no liquefaction zone, and no Alquist-Priolo fault setback. LADBS has pre-approved a library of ADU designs including some prefab and modular options that bypass standard plan check entirely, compressing permitting from six-plus months to weeks. We verify your parcel’s eligibility through LADBS records during our free site evaluation before quoting any fast-track timeline. Call (213) 329-7167 to check your lot - estimates are free.
Almost always: pier-and-beam foundation with no seismic ties, uninsulated stud walls, and original knob-and-tube or early Romex wiring that can’t support a second dwelling unit. On a 1928 Spanish Colonial Revival in West Adams, we pulled the garage slab and found the rear stem wall had settled four inches with no anchor bolts and knob-and-tube feeding a subpanel. Our tech photographed every condition, priced the foundation and rewire as written allowances, and got owner sign-off before a single form was set. The upgraded scope ran past the original estimate, but every dollar was documented and approved in advance. Call (213) 329-7167 - we probe before we promise.
Yes, if the parcel falls within the city-designated Very High Fire Hazard Severity Zone. WUI requirements include Class A roofing, fire-resistant siding such as James Hardie fiber-cement, and ember-resistant vents. These materials and methods add $35,000-$65,000 to a typical detached ADU build compared to flatland construction. We pull the fire hazard designation during our initial site survey and price the full WUI package in writing before you sign. Call (213) 329-7167 for a hazard-zone check - estimates are free.
We don’t let surprises become change orders. Our process is: probe and photograph existing conditions during the estimate phase, price all likely upgrade scenarios as written allowances, then get your sign-off on a capped contingency before work starts. If we find failed waterproofing or undersized framing once walls are open, we stop, photograph the condition, price the fix against the pre-approved allowance schedule, and require your written approval before proceeding. Under Haven Standard, Clause 5, no work proceeds on an unpriced condition. Call (213) 329-7167 to walk through our documentation process - estimates are free.
No. Los Angeles eliminated owner-occupancy requirements and off-street parking requirements for most ADUs in 2019, which is a major reason the city became the highest-volume ADU market in California. You can build a detached ADU on a rental property, sell it with a TIC agreement, or use it as you choose. Some specific zones and hillside areas retain minor restrictions, but the blanket rules are gone. We verify your specific parcel’s zoning during our free estimate and quote against the actual requirements that apply. Call (213) 329-7167 for a zoning check - estimates are free.
Ready to price your project? Call (213) 329-7167 to schedule your free estimate. Every project receives a written price before any work begins, a documented photo record on every visit, and the protection of our 365-Day Done Right Promise - all under The Haven Standard, in writing, from day one.
Written by Nadia Ellery, Owner at Ellery ADU Studio, serving Los Angeles since 2015.