New Detached ADU in Los Angeles - One Fixed Price, Permits Handled

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 ground-up build, with prefab and modular options starting closer to $180,000-$320,000 depending on foundation, utility trenching, and whether your property sits in a CAL FIRE Very High Fire Hazard Severity Zone. We’re Ellery ADU Studio Westchester, and our New Detached ADU team has designed, permitted, and built 900+ ADUs since 2015 - the year California’s ADU rules changed. Dispatch and scheduling run from our Los Angeles office, and crews serve Los Angeles neighborhoods from Pacific Palisades to Boyle Heights without the scheduling lag that comes from routing teams from outside the county. Call (213) 698-7591 to schedule your free estimate.

Call (213) 698-7591

Why Ellery ADU Studio Westchester Is Los Angeles’s Preferred New Detached ADU Company

Los Angeles has issued more ADU permits than any other municipality in California, and we’ve been part of that surge since the beginning. Our 900+ projects include everything from 400-square-foot studio ADUs in Silver Lake backyards to two-bedroom detached units in the San Fernando Valley, each with a written price before work started and a documented photo record when work was complete.

Our Los Angeles clients receive the same documentation we use internally: permit set, photo record, written scope, and the Haven Standard contract with Clause 1 (written price before any work starts) and Clause 5 (no surprises - scope locked at signing). Reviews from Los Angeles homeowners consistently cite our upfront pricing and our fluency with LADBS’s dual-track permit system, which matters here more than anywhere else in the state.

Response time to Los Angeles inquiries is same-day during business hours. A live person answers calls 24/7 - no voicemail queue, no callback promise that doesn’t materialize. We coordinate prefab and modular systems from brands including Plant Prefab and Boxabl within the same single contract, so neither the designer nor the builder can point at the other when something is off.

Our New Detached ADU Services in Los Angeles

Custom Built ADU

Custom built ADUs in Los Angeles give you full control over layout, materials, and finish level. We design the permit set in-house, build from your approved drawings, and manage LADBS inspections start to finish. On a recent project near Eagle Rock, we specified James Hardie fiber-cement siding to meet WUI ignition-resistant requirements for that hillside zone - a flatland builder might have missed the CAL FIRE designation entirely. Custom builds in Los Angeles typically run $220,000-$450,000 all-in, drawings through final inspection, with the written price locked under Haven Standard Clause 1 before we break ground.

Prefab ADU Installation

Prefab ADU installation in Los Angeles works well on flat lots with clear crane access and straightforward utility tie-ins. We specify and coordinate Plant Prefab and Boxabl systems within our single contract, handling site prep, foundation, utility trenching, and LADBS sign-off - not just dropping a box in your yard. Prefab units in Los Angeles typically run $180,000-$320,000 depending on foundation requirements and whether we need to upgrade your main electrical service to support the new load. The permit set is still our core product; prefab doesn’t mean skipping LADBS scrutiny.

Modular ADU

Modular ADUs in Los Angeles are built off-site in factory conditions, then transported and set on your foundation. This works well in neighborhoods with tight side-yard setbacks where stick-built framing would eat too much of the buildable footprint. We coordinate modular delivery windows with LADBS inspection schedules so you’re not paying for a crane to sit idle waiting for a sign-off. Modular pricing in Los Angeles overlaps with prefab, typically $190,000-$340,000, with the same written-price guarantee before work begins.

Studio ADU

Studio ADUs - 400 to 500 square feet, kitchenette and bath, no separate bedroom - are the most common detached ADU we permit in Los Angeles. They’re popular with homeowners in Highland Park and Silver Lake who want rental income without the footprint of a larger unit. LA’s mild climate makes mini-split heat pumps the near-universal HVAC solution for studio ADUs, avoiding the ductwork that would eat ceiling height in a small space. Studio ADUs in Los Angeles typically run $180,000-$280,000 for custom builds, less for prefab or modular options.

1-Bed & 2-Bed ADU

One-bedroom and two-bedroom detached ADUs in Los Angeles start at roughly 600 square feet and run to 1,200 square feet under state guidelines. These are popular in the San Fernando Valley, where 1950s-1970s postwar tract homes on 6,000-7,500 square foot lots have room to build. The dominant local challenge: those same tract homes often have detached two-car garages wired with original 60-amp or 100-amp sub-panels that must be upgraded to support a converted or replaced unit. We inspect electrical service during our initial site visit and write any upgrade into the contract as a line-item allowance - not a surprise six weeks into construction.

Trusted Brands We Service in Los Angeles

We specify and coordinate prefab and modular systems from Plant Prefab, Boxabl, and Tuff Shed within our single-contract design-build model, and we use James Hardie fiber-cement siding on custom builds where CAL FIRE WUI requirements apply. Our Los Angeles office stocks common hardware and maintains relationships with local LADBS-approved material suppliers, which means faster turnaround when an inspector requests a substitution or when wildfire-zone requirements change mid-project. Every brand we specify is documented in your permit set, not chosen ad hoc on site.

Common New Detached ADU Problems We See in Los Angeles Homes

• Original 60-amp garage sub-panels that won’t support a converted unit. In Panorama City, Van Nuys, and across the Valley, we open detached garages and find 1950s-1970s electrical service that was never meant to power a dwelling. Upgrading to 200-amp service mid-permit with no allowance written into the contract is how ADU budgets collapse. We inspect and allow for this before demo.
• Unpermitted 1980s-2000s additions buried in the structure. LADBS won’t sign off on a New Detached ADU until non-code walls are either legalized via as-built permit or removed. We’ve found previous owners’ unpermitted bathroom additions, second-story lofts, and unpermitted kitchenettes hidden behind drywall. The as-built permit pathway is standard practice for us, not an afterthought.
• Failed waterproofing and undersized framing on raised wood foundations. Older 1920s-1940s bungalows in Highland Park, Silver Lake, and Mid-City sit on raised wood foundations with crawl spaces that weren’t designed for modern plumbing tie-ins. Open the subfloor and you find dry rot, termite damage, or sill plates that don’t meet current shear-wall requirements. We price this in writing before we touch it.
• CAL FIRE Very High Fire Hazard Severity Zone requirements. Hollywood Hills, Topanga, Pacific Palisades, portions of Eagle Rock - these zones trigger WUI rules that add Class A roofing, ember-resistant vents, and noncombustible siding. A builder quoting identical square footage in flatland Los Angeles without checking the fire zone is setting you up for a mid-project change order that can run tens of thousands.

Pricing for New Detached ADU in Los Angeles, CA

The Los Angeles Dual-Track Reality: What Actually Happens When We Open Your Walls

Because LADBS records are full of unpermitted garage and backyard conversions from the 1980s-2000s, a large share of Los Angeles ADU work is actually dual-track - pulling an as-built permit to legalize an existing structure while simultaneously building new under the post-2020 streamlined ADU rules, a negotiation that contractors in Burbank, Long Beach, or Torrance don’t face at the same volume. Los Angeles has issued more ADU permits than any other California municipality, so inspectors here are fluent in both pathways. But fluency doesn’t mean leniency. An inspector who sees unpermitted square footage in your detached structure will red-tag the whole project until it’s resolved.

In Panorama City, we opened a 1958 tract home’s detached two-car garage for a New Detached ADU and found original 60-amp wiring feeding the structure, dry-rotted sill plates where the slab met the framing, and a previous owner’s unpermitted 1990s bathroom addition buried behind drywall. We pulled the as-built permit through LADBS, wrote a wiring-upgrade allowance into the contract before demo, and priced the framing repairs in writing before our tech touched a single stud - the homeowner approved the change order the same day the walls came open. That’s how we work. Inspection first, allowances written into the contract, and any surprise priced and approved in writing before we touch it. Under Clause 5 of the Haven Standard, the scope is locked at signing; no door-side upsells, no scope creep.

We Also Serve Cities Near Los Angeles

Our crews work throughout the metro area, and we regularly permit and build New Detached ADU in Los Angeles for clients whose projects spill into neighboring jurisdictions. We also serve South Gate, Gardena, Inglewood, and Compton - each with its own building department, its own inspector personalities, and its own variation on California’s statewide ADU rules. The dual-track LADBS experience doesn’t directly translate, but our fluency with as-built permits and written allowances does.

FAQs - New Detached ADU in Los Angeles