Trusted New Detached ADU for Los Angeles Homeowners
A new detached ADU in Los Angeles typically costs $350,000-$650,000 all-in, from the first survey to final inspection, depending on size, finish level, and whether you build custom or go prefab. Ellery ADU Studio has designed, permitted, and built over 900 ADUs since 2015, every one at a written price agreed to before work started. We’re a design-build studio, not a designer who hands off to a contractor, so the drawings, the permit set, and the construction live under one contract with one accountable party.
Los Angeles homeowners call us when they’ve already talked to an architect who quoted $25,000 for drawings with no construction price in sight, or when a contractor offered a “rough estimate” that ballooned once permits hit complications. We solve that with The Haven Standard: a written price before any work starts, a documented photo record on every site visit, and a 365-Day Done Right Promise backed in writing. Nadia Ellery founded the studio in 2015, the year California’s ADU laws began their major shift, specifically to close the designer-versus-builder blame gap that derails most projects. Call (424) 551-7706 to schedule your free estimate. A live person answers 24/7.
What Our New Detached ADU Service Includes
Custom Built ADU
A custom built ADU is stick-framed on your property from foundation to finish, designed to your specific site conditions and aesthetic preferences. You need this when your lot has unusual constraints, a steep grade, or you want materials and layouts that prefab can’t accommodate. At Ellery ADU Studio Los Angeles, we produce the full permit set in-house, including structural calculations and Title 24 energy compliance, then build from those drawings under the same contract. The written price covers everything from the first survey to the final certificate of occupancy, with no change orders unless you request a scope change in writing.
Prefab ADU Installation
Prefab ADU installation means a factory-built unit delivered to your Los Angeles property and craned onto a prepared foundation, typically cutting site time from 12 months to 3-4 months. You need this when speed matters, when you want factory-controlled quality, or when your budget is tighter and the standardized design works for your lot. We specify and coordinate prefab systems from Abodu, Cover, and other manufacturers within our single-contract model, handling Los Angeles Department of Building and Safety plan check, utility tie-ins, and finish work that the factory doesn’t cover. The written price includes the unit, transport, crane, foundation, and all site connections.
Modular ADU
A modular ADU is built in factory sections, transported, and assembled on site, offering more layout flexibility than single-unit prefab while retaining factory quality control. You need this when your lot requires a multi-section design, when you want higher-end finishes than standard prefab allows, or when you’re building a 2-bedroom unit that exceeds single-module dimensions. Ellery ADU Studio Los Angeles coordinates modular systems from Dvele and other manufacturers, managing the interface between factory production and site prep so neither party blames the other for delays. Our permit set accounts for modular-specific structural connections and Los Angeles seismic requirements before any module ships.
Studio ADU
A studio ADU is a single-room detached unit with kitchenette and bath, typically 300-450 square feet, the most common starting point for Los Angeles homeowners testing the ADU market. You need this when your lot is limited on space, when rental income is the primary goal and a full bedroom isn’t necessary, or when you’re building for a specific use like a home office or guest quarters. We design studio ADUs to maximize usable square footage within Los Angeles setback requirements, often finding extra interior volume through strategic ceiling heights and built-in storage. Every studio permit set includes fire separation, egress window placement, and utility routing optimized for your specific backyard layout.
1-Bed & 2-Bed ADU
A 1-bedroom or 2-bedroom detached ADU adds private sleeping quarters, making it suitable for long-term rental, family housing, or aging-in-place arrangements. You need this when your target tenant is a small family, when you’re housing an adult relative who needs privacy, or when rental income projections justify the larger investment. Ellery ADU Studio Los Angeles sizes these units to the maximum allowed under your lot’s floor area ratio, often finding additional square footage through careful interpretation of Los Angeles Baseline Mansionization and R-1 zone rules. The written price includes all bedrooms, baths, kitchen, living space, and the full utility infrastructure to support independent occupancy.
What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
- 2
You get an upfront price rangeHonest numbers before anyone is dispatched.
- 3
A background-checked tech heads outLicensed & insured, dispatched right away.
- 4
You approve before work beginsNothing starts until you say go.
Brands We Service for New Detached ADU
We specify and coordinate prefab and modular systems from Abodu, Cover, Dvele, Mighty Buildings, Boxabl, Plant Prefab, Tuff Shed, and James Hardie, integrating each into our single-contract design-build model. With Abodu, we’ve coordinated dozens of installations across Los Angeles neighborhoods from Venice to Studio City, managing the critical path between factory delivery windows and LADBS inspection schedules. Our Cover projects typically involve their panelized system, where we handle the foundation and utility rough-in while the factory produces wall panels, then manage the weather-tight assembly and interior finish on site. James Hardie siding is our default specification for custom builds in fire hazard zones like the hills above Beverly Hills and West Hollywood, where non-combustible exterior cladding isn’t just preferable, it’s often required.
Whether your project involves Abodu, Cover, Dvele, or any other manufacturer, we can help. Our permit sets are manufacturer-agnostic where the code allows, and we maintain direct relationships with factory engineering teams so design changes don’t stall in voicemail queues. The same written-price guarantee applies: Haven Standard, Clause 1, locks your number before any work begins.
Signs You Need New Detached ADU Right Now
- Your garage conversion was denied by LADBS. Los Angeles Department of Building and Safety rejects garage conversions for seismic, fire separation, or parking replacement reasons more often than homeowners expect. A new detached ADU sidesteps the existing structure entirely, giving you a clean permit path on a fresh foundation with no inherited code violations.
- Your property’s floor area ratio is maxed out on the main house. Los Angeles calculates ADU square footage separately from your primary residence in most zones, meaning a detached unit may be your only path to add legal rental square footage. We’ve found 400-800 square feet of additional capacity on lots where homeowners assumed they were built out.
- You’re carrying a mortgage rate from 2022-2024 and need income to offset it. Los Angeles rental rates for permitted ADUs typically run $2,500-$4,500 monthly for studio to 2-bedroom units, depending on neighborhood. The math on a $400,000 ADU investment often pencils to positive cash flow within 18-24 months, but only if the unit is permitted, inspected, and legally rentable.
- Your family situation is changing within 18 months. Aging parents, adult children returning, or a home office requirement with real privacy needs all point to detached ADU over interior conversion. The permitting and construction timeline for a new detached unit in Los Angeles is 12-18 months from contract to occupancy; starting now means readiness when the need arrives.
- You’ve received a written estimate that feels vague or incomplete. Estimates with line items like “allowance for unforeseen conditions” or “TBD upon permit approval” are not written prices, they’re open-ended commitments. Under Haven Standard, Clause 1, our written price is fixed at signing; Clause 5 (No Surprises) explicitly prohibits door-side upsells or scope creep.
Our New Detached ADU Process - Step by Step
- 1
Site Analysis & Feasibility Report. We survey your Los Angeles lot, document existing structures with measured drawings, and produce a written feasibility report within 10 business days. This report includes your maximum allowable ADU square footage under current LADBS and zoning rules, setback requirements, utility capacity, and any obvious constraints like oak tree protection zones or hillside grading triggers. You receive a documented photo record of our findings, not a summary of how it felt.
- 2
Design & Permit Set Production. Our architects produce the full construction document set, including structural calculations, Title 24 energy compliance, and landscape plans if required by your specific zone. For prefab or modular projects, we coordinate with factory engineering to ensure the permit set matches the delivered product exactly. The permit set is the core product, not an afterthought, and we don’t start construction until LADBS accepts it.
- 3
Written Price & Contract. Once the permit set is complete and we’ve received contractor bids for any subcontracted trades, we present a single written price covering all design, permitting, and construction through final inspection. Haven Standard, Clause 1 requires this price to be fixed before any work begins; Clause 5 locks the scope at signing. You receive the full contract, warranty terms, and payment schedule to review with no pressure to decide immediately.
- 4
Permit Submission & Plan Check. We submit to LADBS and manage the plan check process, including any corrections or additional documentation requested. Our 2015 founding date means we’ve navigated every major ADU regulatory shift in Los Angeles, from the 2016 state preemption to the 2020 and 2023 expansion bills. We know which plan checkers require which details, and we front-load those into the initial submittal to minimize revision cycles.
- 5
Construction, Inspection & Closeout. Our background-checked, uniformed crews build from the permitted drawings, with a documented photo record on every site visit. We pull all required permits, schedule all inspections, and don’t request final payment until LADBS issues the certificate of occupancy. The 365-Day Done Right Promise then begins: if anything is not built to the permitted drawings, we make it right, in writing, with no dispute about whose responsibility it was.
How Much Does New Detached ADU Cost in Los Angeles?
A typical new detached ADU in Los Angeles runs $350,000-$650,000 all-in, from initial survey through final inspection. Studio units at the smaller end with prefab delivery typically land in the $350,000-$450,000 range. Custom 1-bedroom units run $400,000-$550,000 depending on finish level and site complexity. Full 2-bedroom custom builds with premium finishes often reach $550,000-$650,000, particularly in hillside areas of West Los Angeles, Beverly Hills, or Studio City where grading and foundation work add significant cost.
| ADU Type | Typical Range (Los Angeles) | Primary Cost Drivers |
|---|---|---|
| Studio Prefab (300-400 sq ft) | $350,000-$450,000 | Foundation, utility tie-ins, transport/crane |
| Studio Custom (350-450 sq ft) | $375,000-$500,000 | Materials, finish level, site access |
| 1-Bed Prefab or Modular (450-600 sq ft) | $400,000-$525,000 | Module count, foundation complexity |
| 1-Bed Custom (500-650 sq ft) | $450,000-$600,000 | Structural requirements, energy code compliance |
| 2-Bed Custom (700-1,000 sq ft) | $550,000-$650,000 | Size, hillside/grading, premium finishes |
Several factors push prices within these ranges. Site conditions matter: flat lots in Westchester or Inglewood with good soil and clear utility access cost less than hillside properties in Sherman Oaks or the Hollywood Hills where engineered foundations and retaining walls add $50,000-$150,000. Finish level matters: vinyl flooring and standard fixtures versus hardwood, tile, and designer kitchens can swing a 1-bedroom unit by $75,000. Utility distance matters: if your main house sewer lateral is 80 feet from the ADU location, trenching and pipe sizing add real cost that some estimates bury in “allowances.”
To avoid overpaying, get a written line-item quote, not a summary number. Our free estimates specify foundation type and depth, structural system, insulation R-values, window specifications, plumbing fixture models, electrical panel size, and every other material that affects your 30-year ownership cost. We also offer a Free Second Opinion on any written estimate already in hand, we’ll review it against the permit set and tell you where the gaps are. Call (424) 551-7706 for your written estimate.
New Detached ADU Near Los Angeles - Our Service Area
We design and build new detached ADUs across Los Angeles and the immediate metro core, including Culver City, West Los Angeles, Santa Monica, Venice, Westchester, Beverly Hills, West Hollywood, Inglewood, Hawthorne, Studio City, and Sherman Oaks. Typical initial site analysis scheduling is 5-7 business days from call to visit. Permit timeline varies by jurisdiction: LADBS plan check for detached ADUs currently runs 8-14 weeks for straightforward projects, with Culver City and Santa Monica sometimes faster, Beverly Hills sometimes slower due to additional design review requirements. We know the specific submittal requirements for each city and don’t waste weeks on incomplete applications.
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.
Frequently Asked Questions - New Detached ADU in Los Angeles
A new detached ADU is a separate, freestanding residential unit built from the ground up on your property, not converted from an existing structure. It has its own foundation, walls, roof, kitchen, bath, and utility connections, and is legally rentable as independent housing under California state law. Ellery ADU Studio Los Angeles handles the full process from feasibility study through certificate of occupancy under one contract at one written price.
A new detached ADU in Los Angeles typically takes 12-18 months from signed contract to move-in ready, split roughly evenly between design/permitting and construction. Prefab and modular projects can compress the construction phase to 3-4 months, but permitting still requires the same LADBS plan check timeline. Call (424) 551-7706 to discuss your specific lot’s timeline based on current plan check queues.
A new detached ADU in Los Angeles typically costs $350,000-$650,000 all-in, with studio prefab units at the lower end and custom 2-bedroom builds at the upper end. Site conditions, finish level, and utility routing are the three biggest variables within that range. Every Ellery ADU Studio project is quoted with a written price before any work begins, per Haven Standard, Clause 1; call (424) 551-7706 for your specific estimate.
Yes, we specify and coordinate Abodu, Cover, Dvele, and other prefab and modular brands within our single-contract design-build model. We’ve completed installations with each manufacturer across Los Angeles neighborhoods and maintain direct engineering relationships to resolve factory-to-site issues without delay. The written price covers the unit, transport, foundation, utility connections, and all finish work.
New detached ADU construction is planned work, not an emergency service, and we don’t market urgency around projects that require 12-18 months of design and permitting. If you have an urgent housing need, a garage conversion or interior Junior ADU may be faster to permit and build; we can assess that in our free feasibility report. For existing ADU issues like plumbing leaks or electrical failures, our construction team can respond; call (424) 551-7706 and a live person will direct your call appropriately.
We provide a 365-Day Done Right Promise backed in writing: if the finished ADU is not built to the permitted drawings, Ellery makes it right at our expense. This covers structural, mechanical, electrical, and plumbing systems, plus finish quality. The warranty is in the contract you sign before work starts, not a verbal promise after the fact.
Gather your property’s Assessor’s Parcel Number (APN), any existing survey or plot plan, and your rough idea of ADU size and use (rental, family, office). We’ll handle the rest in our site analysis, including zoning verification, utility capacity research, and preliminary setback calculations. Call (424) 551-7706 to schedule; estimates are free, written, and include no obligation to proceed.
Schedule Your New Detached ADU Service in Los Angeles Today
Call (424) 551-7706 to schedule your free estimate. A live person answers 24/7, and you’ll receive a written price before any work begins, per Haven Standard, Clause 1. Nadia Ellery and the team at Ellery ADU Studio Los Angeles have designed, permitted, and built over 900 ADUs since 2015, every one with a documented photo record and our 365-Day Done Right Promise. Whether you’re in Venice, Studio City, or anywhere between, we’ll tell you exactly what your lot allows and exactly what it costs to build.
Written by Nadia Ellery, Owner at Ellery ADU Studio, serving Los Angeles since 2015.