A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateFast, Reliable ADU Builders Across Los Angeles
ADU construction in Los Angeles typically runs $180,000 to $450,000 for a detached unit, with garage conversions starting around $120,000 and JADUs between $65,000 and $150,000, depending on the condition of the existing structure and what the city requires once walls are open. We’re Fielding ADU Los Angeles, and we’ve been building accessory dwelling units, garage conversions, and room additions across this city long enough to know that the quote you sign on day one is only as good as the inspection behind it. If you’re considering an ADU on your Los Angeles property, call (213) 732-1415 and we’ll walk the lot with you, identify the real costs, and put the price in writing.
We serve every corner of Los Angeles, from Echo Park to Sherman Oaks to West Adams, and our crews know what these neighborhoods throw at you. Pre-war bungalows, post-war ranches, hillside lots, flat roofs, detached garages with foundations that predate modern seismic codes. None of it surprises us. That matters more than most homeowners realize until the first change order hits the table.
Why Fielding ADU Los Angeles Is Los Angeles’s Preferred ADU Builders Company
Fielding ADU Builders is the ADU and room-addition specialist inside the Garrison Partners family. Garrison Partners has been building to The Garrison Standard since 2006, and we agreed to hold ourselves to that same bar here in Los Angeles. What that means for you is specific: a written price before any work starts, permitted work done by the book, and a full year of written guarantee on every project. Most contractors in this city won’t put the guarantee on paper. We do, every time.
Reed Calloway leads our Los Angeles operation, and he runs crews the way a good general contractor should: background-checked, uniformed, and on site when they say they’ll be. Every person who steps onto your property has been verified before they arrive. You’ll know exactly who’s working on your home. Call us at noon or midnight and a live person answers. No voicemail, no callback queue. That’s the Garrison Code: show up in the window, price in writing, by the book, leave it clean, stand behind it for a year.
Our ADU Builders team works across ADU Builders in Los Angeles from a metro office that coordinates scheduling and dispatch for every job in the city. We know which inspectors work which districts, what the LADBS plan checkers are flagging this quarter, and which building departments move faster than others. Local knowledge like that saves you weeks on a permit and thousands on a rework.
Detached ADU in Los Angeles
A Detached ADU in Los Angeles is a new standalone living unit built from the ground up in your rear yard, and it’s the most common path for homeowners whose lots are large enough to support it. Expect 400 to 1,200 square feet, a full kitchen and bath, and a construction timeline of 6 to 12 months from permit approval to final inspection. On a typical Los Angeles lot, a detached ADU runs $280,000 to $450,000 depending on size, site access, and foundation conditions. Hillside lots in Mount Washington or Highland Park push that higher; flat lots in the Valley keep it lower.
Foundation and Seismic Work
Every detached ADU in Los Angeles requires a structural foundation engineered to current LADBS standards. On a new build, that means excavation, forming, rebar, and a poured concrete footing tied to the seismic design category for your address. This isn’t optional, and it isn’t where you want a contractor cutting corners.
Utility Connections
New detached units need their own water, sewer, and electrical runs, and in Los Angeles that often means trenching across an existing yard and tying into a main line that may be 70 years old. We price this work honestly up front, including the cost of restoring your landscaping after the trench closes.
JADU in Los Angeles
A JADU in Los Angeles is a junior accessory dwelling unit, typically 500 square feet or less, built within the existing footprint of your single-family home. Think converted garage, finished attic, or a sectioned-off portion of the main house with its own entrance, kitchenette, and bathroom. JADUs are the most affordable way to add a legal rental unit, typically running $65,000 to $150,000, and permit approval moves faster than a detached build because there’s no new foundation or structural shell required. Under state law and Los Angeles ordinances, most single-family lots can now add a JADU alongside one or two ADUs, which makes this the highest-return-per-square-foot option for many homeowners.
Interior Conversion Scope
The work inside a JADU conversion is mostly interior: framing out the kitchenette, running new electrical and plumbing branches, adding sound separation at shared walls, and installing a separate entry. The challenge is what’s already inside your walls, and in a 1920s or 1950s Los Angeles home, that often means obsolete wiring, undersized framing, or failed waterproofing around the perimeter.
Permit Triggers
Opening walls for a JADU triggers code upgrades. LADBS will require a full electrical panel evaluation, smoke and carbon monoxide detection, and in many cases a seismic evaluation of the existing structure. We walk you through each trigger before we quote, so the number you approve includes what the city will actually demand.
Trusted Brands We Service in Los Angeles
Some Los Angeles homeowners want a prefab unit set by crane; others want a custom stick-built ADU that matches the character of their 1920s bungalow. We support both. Fielding ADU Los Angeles works directly with leading prefab and modular platforms including Cover, Dvele, and Boxabl, and we also build conventional ADUs using James Hardie siding and Tuff Shed-style structures where the budget calls for it. We stock common prefab connection parts and finish materials locally in Los Angeles, so when a Cover module needs a specific flashing or a Dvele unit needs a particular trim detail, we’re not waiting on a shipment. The right build method depends on your lot, your timeline, and your budget. We’ll help you match it.
Common ADU Builders Problems We See in Los Angeles Homes
If you’re converting an older Los Angeles structure, these are the conditions we run into most often. Each one has a standard fix, and we pre-price all of them with written allowances so the change order never comes as a surprise.
- Unreinforced or lightly reinforced foundation slabs. Pre-1950s detached garages in neighborhoods like Silver Lake, Echo Park, and West Adams often sit on 4-inch slabs with no anchor bolts. LADBS retrofit triggers require bolting, cripple-wall bracing, or full foundation replacement before the space becomes legal living area.
- Knob-and-tube or aluminum branch wiring. Homes built before 1950 frequently still have active knob-and-tube circuits, and 1960s and 1970s homes often have aluminum branch wiring. Converting the space triggers a full electrical evaluation, and patching instead of rewiring leaves an uninsurable fire hazard.
- Termite and dry-rot damage behind old stucco or siding. Decades of sprinkler overspray and the marine layer’s morning moisture mean wood framing in Los Angeles garages is often compromised. We find studs that crumble when you tap them. The fix is standard: replace damaged members before the inspections.
- Failed waterproofing at roof-to-wall intersections. Many flat-roofed Los Angeles garages were built with no flashing at the parapet. The first real winter rain finds every gap. Mold follows. We flash and seal everything as part of the conversion, not as an afterthought.
Pricing for ADU Builders in Los Angeles, CA
Here are the ranges we quote for ADU work in Los Angeles, based on current material and labor costs in this market. These are all-in construction numbers, excluding city permit fees, which typically add $8,000 to $25,000 depending on scope and inspection requirements.
- Detached ADU (new construction, 400 – 1,200 sq ft): $280,000 – $450,000
- Garage conversion ADU: $120,000 – $220,000
- JADU (interior conversion, up to 500 sq ft): $65,000 – $150,000
- Prefab or modular ADU (platform unit plus site work): $180,000 – $380,000
- Seismic retrofit only (pre-1950 garage): $15,000 – $45,000
What moves the price: foundation condition, site access for equipment, the age of your electrical panel, and what LADBS requires once walls are open. We put every one of these conditions in writing as a line-item allowance before you sign. Call (213) 732-1415 and we’ll give you a real number, not a range that shifts later.
We Also Serve Cities Near Los Angeles
While this page is for Los Angeles homeowners, our crews regularly work in the surrounding communities. If you’re in Huntington Park, Gardena, Culver City, or West Hollywood, the same written-price-first standard applies. We schedule across the greater Los Angeles basin and coordinate from our Los Angeles office.
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 About ADU Builders in Los Angeles
LADBS typically requires anchor bolts connecting the mudsill to the foundation, cripple-wall bracing with plywood shear panels, and in many cases full foundation replacement if the existing slab is unreinforced or cracked. A structural engineer evaluates your specific structure, and the retrofit scope is written into your permit set before any work starts. We use Simpson Strong-Tie anchors and plywood shear panels as standard. Call (213) 732-1415 for an exact evaluation of your garage.
In most cases, yes. LADBS requires the ADU’s new circuits to be fully modern and separately metered or sub-paneled, and any knob-and-tube that runs through the conversion area must be removed or isolated. You may not need to rewire the entire main house, but any obsolete wiring exposed during the ADU work must be brought up to current code. We’ll map your electrical system during the inspection and tell you exactly what the permit triggers.
Yes. Flat-roof conversions in Los Angeles must meet current code for roof drainage, parapet flashing, and moisture barriers at all roof-to-wall intersections. If your existing garage has no flashing or a failed built-up roof, the permit will require correction before insulation and drywall go in. We include this in every flat-roof conversion quote because we know the first winter rain will test it. Call (213) 732-1415 to schedule a roof and drainage evaluation.
California law now allows up to two additional dwelling units on most single-family lots: one full ADU (attached or detached) and one JADU within the existing home. SB 9 separately allows lot splits and duplex construction under specific conditions. Los Angeles has adopted these provisions into its local zoning code. The practical result: most Los Angeles homeowners can build a detached ADU in the rear yard plus a JADU in the existing house or garage. We’ll evaluate your specific lot and zoning during the free estimate.
A proper Los Angeles ADU contract includes written allowances for specific hidden conditions: termite damage repair, dry-rot replacement, seismic retrofit scope, electrical panel upgrades, and waterproofing corrections. Each allowance states the unit cost and the estimated quantity, so when a condition is discovered, the change order is calculated from numbers you already approved. If a contractor’s contract doesn’t include written allowances, the change order becomes a negotiation under pressure. Our contracts always include them. Call (213) 732-1415 and we’ll show you exactly how our allowance structure works before you sign anything.
The Los Angeles Garage Conversion Trap: Why Your Quote Moves
Los Angeles is ground zero for ADU construction. State laws like SB 9 and local ordinances now allow up to two units plus a JADU on single-family lots, and that’s created enormous demand for converting garages, attics, and backyards in neighborhoods dominated by 1920s bungalows and post-war ranch homes. But here’s what we tell every homeowner before they sign with anyone: the city’s pre-1950s detached garages often sit on unreinforced masonry or lightly reinforced concrete foundations that are seismically vulnerable under LADBS retrofit triggers. Converting one to an ADU routinely requires bolting, cripple-wall bracing, or full foundation replacement before any living space is legal.
This is the single biggest reason a remodel quote moves mid-project. A builder gives a lowball quote on a 1920s bungalow garage conversion, then hits a crumbled unreinforced foundation and demands a 40% change order without written approval. You’re either paying it or firing the crew and starting over. We handle it differently. Inspection first, allowances written into the contract, and any surprise priced and approved in writing before we touch it. In Silver Lake, we converted a 1938 detached garage into an ADU where the original foundation was a 4-inch unreinforced slab with zero anchor bolts. Opening the walls revealed knob-and-tube wiring and termite-compromised studs, so our permit triggered a full electrical rewire and seismic retrofit with Simpson Strong-Tie anchors and plywood shear panels. Because we had written allowances for exactly these conditions, the owner approved the change order in one day and we still finished before the rainy season.
The mild Mediterranean climate of Los Angeles allows for year-round ADU construction, which is a real advantage most homeowners don’t think about until they’re scheduling. You’re not racing a freeze or a mud season. That said, “no freeze” doesn’t mean “no waterproofing.” Crews working here sometimes skip flashing at roof-to-wall intersections because they assume LA’s dry climate means it won’t matter. It matters. The first winter rain finds every gap. We flash and seal everything as standard, and our written guarantee covers waterproofing defects for a full year. If something fails, we come back and make it right at no charge. That’s the 365-Day Done Right Promise, and it’s on paper, not a handshake.
If you’re pricing ADU construction in Los Angeles, get a written quote that includes allowances for the conditions your house actually has. Call Reed Calloway and the Fielding ADU Los Angeles team at (213) 732-1415. We’ll walk your property, open the conversation with what we actually see, and hand you a price in writing before any work starts.
Written by Reed Calloway, Owner at Fielding ADU Los Angeles, building to The Garrison Standard in Los Angeles.
