New Detached ADU in Los Angeles - Design, Permits and Build Under One Contract

Fast, Reliable New Detached ADU Across Los Angeles

A new detached ADU in Los Angeles typically runs $220,000-$450,000 all-in for a custom build and $180,000-$320,000 for a prefab or modular unit, with LADBS permitting timelines ranging from 3-8 weeks for Standard Plan projects to 4-6 months for full custom submittals. We handle the architecture, permit set, and construction under one contract at one written price, so the designer and builder are the same entity and the same accountability. Our Los Angeles office coordinates scheduling and site visits across the city, from Silver Lake hillside lots to post-war Valley ranches in Reseda and Van Nuys. Call (424) 407-8266 to schedule your free estimate and get a written price before any work starts.

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Why Ellery ADU Studio North 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 began their major shift, and a significant share of that work has been here in Los Angeles. The city’s Standard Plan Program, its sheer volume of R1 lots with alley-facing garages, and its mix of 1920s bungalows and 1960s ranches mean every project teaches us something specific about how to get an ADU through LADBS without the delays that stall projects in less experienced hands.

Los Angeles homeowners find us through referral and repeat search, and they consistently describe the difference as documentation: a written price before signing, a photo record from every site visit, and a 365-Day Done Right Promise backed in writing under The Haven Standard. We don’t ask for trust; we hand you the clause.

Response time to Los Angeles neighborhoods runs same-week for initial site visits, with permit status updates and scheduling coordinated from our Los Angeles office. You’ll speak to a live person when you call (424) 407-8266, not a voicemail queue with a callback promise that evaporates.

Our local knowledge runs deep on the conditions that actually affect your quote: which hillside zones trigger CalFire requirements, where LADBS enforces stricter lot-coverage calculations, and how pre-war electrical and sewer systems in West Adams or Jefferson Park behave once you open a wall. That specificity is what keeps your price from moving once work starts.

Our New Detached ADU Services in Los Angeles

Custom Built ADU

A custom built ADU in Los Angeles gives you full control over layout, materials, and how the unit relates to your existing home and yard. On flat lots in neighborhoods like Highland Park or Echo Park, where the Standard Plan Program’s pre-vetted designs may not match your alley access or desired footprint, custom is often the right path. We produce the full permit set in-house, submit to LADBS, and build to those drawings under the same contract. Typical range in Los Angeles: $220,000-$450,000 all-in, depending on size, finishes, and whether the site needs utility work.

Prefab ADU Installation

Prefab ADU installation in Los Angeles leverages factory-built modules that arrive 80-90% complete, cutting on-site construction time to 6-10 weeks versus 4-6 months for stick-built. We specify and coordinate systems from Abodu, Cover, and other manufacturers, handling LADBS plan check, foundation, utility tie-ins, and final inspection as part of our single contract. Prefab works best on lots with clear crane access and straightforward utility connections - common in post-war Valley neighborhoods like Van Nuys and Northridge. Typical range: $180,000-$320,000.

Modular ADU

Modular ADU construction in Los Angeles uses volumetric modules built to California Building Code in a factory setting, then assembled on your foundation. We coordinate with Dvele and other modular partners to ensure the design, engineering, and LADBS submittal are handled as one workflow, not a handoff between designer and builder. Modular shines on tighter sites where minimizing construction duration matters - think hillside lots in Silver Lake or Los Feliz where extended equipment access is difficult. Typical range: $200,000-$380,000.

Studio ADU

A studio ADU in Los Angeles, typically 350-500 square feet, is the most common entry point for homeowners testing the rental market or creating guest space. The LADBS Standard Plan Program includes pre-approved studio designs that can clear plan check in weeks, not months, if your lot qualifies. We pre-screen every Standard Plan candidate for slope, lot coverage, and setback compliance before quoting, because a failed pre-screen sends you back to custom - and we’ve seen that mistake cost Los Angeles homeowners three months. Typical range: $150,000-$280,000.

1-Bed & 2-Bed ADU

One-bedroom and two-bedroom detached ADUs in Los Angeles, generally 500-1,200 square feet, command higher rents and serve multigenerational living better than studios. These sizes align with the upper range of the Standard Plan Program, but they also demand more rigorous utility checks: a 2-bed unit with kitchen and laundry can overload a 100-amp panel or a 3-inch sewer lateral, especially in 1950s-1970s Valley homes. We inspect and price that work upfront, not after permits are pulled. Typical range: $200,000-$450,000.

Trusted 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 - integrating whichever system fits your lot, timeline, and budget into our single-contract workflow. For Los Angeles homeowners, this means factory-built components arrive with engineering already stamped for California seismic and fire codes, and our crew handles the site prep, foundation, utility rough-in, and finish work locally. We don’t drop a module and disappear; we stay through final LADBS inspection and certificate of occupancy. James Hardie siding, in particular, sees heavy use on our hillside ADUs in fire zones where non-combustible exterior cladding is mandated.

Common New Detached ADU Problems We See in Los Angeles Homes

• Knob-and-tube wiring in pre-war garages. On a 1926 bungalow in West Adams with a detached single-car garage on the alley, our crew opened the rear wall for a new detached ADU and found knob-and-tube wiring feeding the garage, a sewer lateral still running to the old clay line, and rot along the garage sill plate where irrigation had pooled for decades. We priced the panel upgrade, lateral replacement, and sill repair as written change orders before we framed - and the homeowner approved them in a single email rather than discovering them mid-build.
• Standard Plan eligibility failures on hillside lots. Because LADBS’s Standard Plan Program pre-approves ADU blueprints at roughly 500-1,200 sq ft, the fastest permitted path for many LA backyards is a pre-vetted plan rather than a custom submittal - but eligibility hinges on slope, lot coverage, and existing-structure setbacks, so a hillside lot in Silver Lake or Laurel Canyon can fail pre-screen and get pushed back into full custom plan check. We run that pre-screen before quoting, not after you’ve paid a deposit.
• Undersized electrical panels in post-war Valley homes. Homes built in Reseda, Canoga Park, and Van Nuys between 1950 and 1975 often carry 100-amp service panels that cannot handle an additional dwelling unit with modern kitchen and laundry loads. We inspect the panel and main service during our initial site visit and include any upgrade in the written base price, not as a surprise once walls are open.
• CalFire fire zone construction requirements. Roughly a third of LA’s residential hillside neighborhoods - Hollywood Hills, Laurel Canyon, Bel Air, Chatsworth - sit inside CalFire-designated Very High Fire Hazard Severity Zones, which impose additional ADU construction requirements including ember-resistant vents, Class A roofing, and non-combustible exterior cladding. These add meaningful cost and complexity that a contractor unfamiliar with hillside work won’t catch until permit correction.

Pricing for New Detached ADU in Los Angeles, CA

We Also Serve Cities Near Los Angeles

Our crews work throughout the metro area, including Los Angeles proper and neighboring cities: Culver City, West Hollywood, Beverly Hills, and Pasadena. Each jurisdiction has its own planning department and ADU ordinance nuances - Culver City’s design review, Pasadena’s historic district overlays - and we maintain current permit workflows for all of them. Scheduling and dispatch are coordinated from our Los Angeles office.

FAQs - New Detached ADU in Los Angeles