A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateTrusted ADU Builders for Los Angeles Homeowners
Adding an accessory dwelling unit in Los Angeles means navigating city permits, lot setbacks, utility hookups, and a construction crew working steps from where your kids sleep. Seedling ADU Los Angeles handles all of it with one written price before we start and a 365-Day Done Right Promise after we finish. Our team, led by Ben Ortega, builds detached ADUs, garage conversions, JADUs, and home additions across Los Angeles with soil testing, foundation work, and framing appropriate for our seismic zones and expansive clay soil. We work with Abodu, Cover, Dvele, and James Hardie materials, and every crew member is background-checked and uniformed. If you’re pricing an ADU in Los Angeles, call (213) 449-7136 for a written line-item estimate.
ADU Construction
ADU Construction is the full build process of an accessory dwelling unit, from the first excavation to the final paint and trim. In Los Angeles, this typically means foundation and structural work, electrical and plumbing rough-in, insulation, drywall, flooring, cabinetry, finishes, and final inspection. Seedling ADU Los Angeles manages every trade with your family’s daily life in mind: shoe covers and drop cloths inside the house, quiet hours respected around school schedules, and a photo of the clean-up before the crew leaves each day. For a standard ADU Construction project in Los Angeles, we provide a written price before any work begins, so you’re never surprised by a change order. Most clients budget $180 – $340 per square foot depending on foundation type, finishes, and utility runs. Call (213) 449-7136 to get your exact number in writing.
Foundation and Site Work
Most Los Angeles lots sit on expansive adobe or clay soil that shifts seasonally. A poured perimeter foundation with proper rebar and anchor bolts is the standard here, not a slab on grade.
We run compaction tests before we dig, then set forms and rebar to current California Building Code standards for seismic zone D. This is the single most important step for an ADU that stays square and crack-free in a city that shakes, and it’s why homeowners across the region trust our ADU Builders - South Gate team with the same care.
Rough-In Through Final Inspection
Once the shell is up and the roof is on, we handle electrical panels, sewer lateral tie-ins, and trenching for utilities. In Los Angeles, LADBS requires a separate meter or a subpanel for most detached ADUs, and we coordinate with DWP or SoCal Gas on every connection.
Your crew supervisor walks you through each inspection point with photos, and we pull every permit ourselves. The final sign-off is scheduled only after we’ve confirmed the job is clean enough to pass the first time, not the second.
Detached ADU
A Detached ADU is a standalone living unit built behind or beside your main house, with its own kitchen, bathroom, entrance, and often its own address. In Los Angeles, state law SB 9 and local ADU ordinances allow most single-family lots zoned R-1 to add one detached unit up to 1,000 square feet without a lot split. Seedling ADU Los Angeles builds detached ADUs with careful attention to your lot’s specific grading, drainage, and privacy lines. Because it’s a separate structure, we’re able to work without closing down your home’s main entrance or disrupting your kitchen. A detached ADU in Los Angeles typically costs $120,000 – $380,000 depending on size, finishes, and utility distances. Call (213) 449-7136 for a written price before you commit to anything.
Setback and Grading Considerations
Los Angeles requires a 4-foot side and rear setback for most detached ADUs, though many lots pre-existing conditions allow less. We measure, stake, and confirm your actual buildable footprint before we ever put numbers in front of you.
Drainage deserves special attention on hillside lots in neighborhoods like Echo Park and Eagle Rock. We grade water away from the unit and often install a French drain or swale as part of the foundation scope, so your new ADU doesn’t become a moisture problem in January.
Prefab Versus Stick-Built Detached Units
A factory-built unit from Abodu, Cover, or Dvele can cut on-site time significantly, but it still needs a foundation, utility trenching, and final connection work. We install these units regularly and know their panel tolerances and connection details.
Stick-built on your lot gives you more flexibility with rooflines and lot shapes. Either way, you get the same written price, the same background-checked crew, and the same 365-Day Done Right Promise.
JADU
A JADU, or Junior Accessory Dwelling Unit, is a smaller living space carved out of the existing footprint of your single-family home, usually a converted bedroom, attached garage, or underused room with its own efficiency kitchen and separate entrance. In Los Angeles, JADUs max out at 500 square feet and are one of the fastest ways to add rentable space because they don’t require a separate utility connection, fire sprinklers, or parking. Seedling ADU Los Angeles builds JADUs that respect the original house structure while adding a lawful, comfortable second unit. A JADU in Los Angeles typically costs $50,000 – $120,000 depending on existing plumbing proximity, electrical upgrades, and soundproofing. Call (213) 449-7136 to see what your floor plan can support.
Working Within Your Existing Footprint
Because a JADU lives inside your current home, the crew works around your family’s daily rhythm. We schedule noisy cutting and tile work during school hours, not at 7 a.m. on a Saturday.
Sound separation is a critical detail most contractors miss. We install a double-layer drywall assembly with resilient channels on shared walls, plus a solid-core entry door, so the unit feels private from day one.
Owner-Occupancy and Rental Rules
Los Angeles allows a JADU only when the property owner lives in either the main house or the JADU. We’ll confirm your property meets this requirement before you spend a dime on design work.
Rent control rules apply differently to JADUs than to detached units in Los Angeles. We point you to the city’s current ordinance and help you understand what the unit can rent for once it’s legal.
ADU Plans
ADU Plans are the architectural and structural drawings that LADBS reviews before issuing your building permit, including site plans, floor plans, elevations, electrical and plumbing layouts, and Title 24 energy calculations. In Los Angeles, you cannot pour a foundation or frame a wall without an approved permit set stamped by a California-licensed architect or engineer. Seedling ADU Los Angeles prepares complete ADU Plans through our design partners, tailored to your lot and your budget. Plan preparation in Los Angeles typically costs $8,000 – $25,000 depending on site complexity, soil conditions, and how many revisions LADBS requests. The cost is folded into your written project price, not billed as a surprise add-on. Call (213) 449-7136 to start with a site visit and a measured survey.
Site Survey and As-Built Drawings
Before any design begins, we measure your existing structures, confirm property lines against county records, and map utility locations. A good survey catches the things that kill a permit: missing easements, fence lines that don’t match the deed, or a main house that was never properly finaled.
We’ve seen Los Angeles homes with unpermitted additions from the 1980s. Our survey flags these early so your ADU permit isn’t held up by a citation on the main house.
The LADBS Review Process
Permit review in Los Angeles usually takes 8 – 16 weeks for a standard ADU Plan set. We submit, track, and respond to every correction request from the plan checker, keeping you updated at each step.
If LADBS rejects a plan for a code issue, we fix it and resubmit at no additional design cost. Your fixed price covers the back-and-forth, so the permit phase doesn’t become a billing event.
ADU Contractor
An ADU Contractor is the licensed general contractor who holds the building permit, manages every trade, schedules inspections, and is legally responsible for the finished unit being code-compliant. In Los Angeles, hiring a contractor who actually carries workers’ compensation and pulls permits in their own name is the difference between a lawful rental unit and an expensive liability. Seedling ADU Los Angeles is that contractor: we pull the permit, we manage the subs, we pass the inspections, and we stand behind the work with a written 365-Day Done Right Promise. A contractor’s markup is typically 15 – 25% of the hard construction cost, and that’s included in our written price as a single line item so you can see exactly what you’re paying for. Call (213) 449-7136 to talk through your project with a live person who has actually built ADUs in Los Angeles.
Who’s Actually on Your Jobsite
Every Seedling crew member is background-checked and wears a uniform with a name tag. You’ll never wonder who is walking through your side gate.
Your project supervisor gives you a phone number and answers it during the build. We don’t hand your job to a rotating cast of subcontractors you’ve never met and can’t reach.
Change Orders and Surprises
In Los Angeles, buried surprises are common: old sewer lines, undocumented fill soil, roots in a water main. When we find something unexpected, you get a written explanation of what was found and what it costs before we touch it.
We don’t bill change orders for our own mistakes. If we framed a wall in the wrong place, that’s our correction, not your invoice.
ADU Design
ADU Design is the architectural and interior planning of your unit: how the kitchen relates to the sleeping area, where the entrance lands, how natural light enters, and what the unit looks like from the street. In Los Angeles, good ADU Design pays for itself in rentability and long-term value, which is why we collaborate with design partners who understand our climate, our architectural vernacular, and our clients’ families. Seedling ADU Los Angeles guides you through layout options, finish selections, and material choices without design-by-upsell. Design fees in Los Angeles typically run $5,000 – $18,000 as part of the overall plan set. You’ll see samples, touch materials, and make selections before we finalize your written price. Call (213) 449-7136 to schedule a design consultation in your home or on a video call.
Layouts That Work for Real Families
A good ADU floor plan puts the kitchen along one wall with a full-size refrigerator and a real cooktop, not a hot plate. We design for actual tenants: a place for shoes, a closet that holds a vacuum, a bathroom door that doesn’t hit the toilet.
For families adding an in-law unit, we plan wider doorways and a curbless shower when mobility matters. For rental units, we prioritize sound separation and outdoor privacy.
Materials That Last in Los Angeles
Our summers are dry, our winters are damp, and the sun is relentless. We specify James Hardie siding for exterior durability in this climate, with paint schedules that can handle UV without fading in two seasons.
Interior materials get the same scrutiny: LVP flooring that tolerates sand and pet claws, quartz counters that don’t stain from coffee, and low-VOC paint so the unit doesn’t off-gas for the first month. We use pet-safe products where there’s a choice, so your dog can walk through the project area without concern.
Backyard ADU
A Backyard ADU is any accessory dwelling unit built in the rear yard of your property, usually where a garage, storage shed, or open lawn currently sits. In Los Angeles, backyard space is often the only buildable area on a narrow lot, which makes this the most common ADU type we build. Seedling ADU Los Angeles handles the full backyard transformation: demolition if needed, foundation, framing, utility trenching, and the final landscaping touch so the unit looks like it belongs. A Backyard ADU in Los Angeles typically costs $120,000 – $350,000 depending on how far utilities have to travel and whether we’re removing an existing structure. Call (213) 449-7136 to schedule a free site walk and get a written number.
Replacing a Garage on the Same Footprint
If you’re converting or replacing a detached garage, the existing slab may or may not be usable. In older Los Angeles neighborhoods like Mar Vista and El Segundo, garage slabs often lack rebar or sit below current flood elevation and have to be removed.
When the garage can stay, a conversion is one of the most cost-effective backyard ADUs you can build, and our ADU Builders in South Pasadena see the same savings on their projects. We’ll tell you honestly which route saves money on your specific lot.
Backyard Access During Construction
Most Los Angeles lots have a narrow side yard as the only path to the back. We protect that path with plywood and keep it clear daily, because it’s also how your kids get to the yard and how your dog gets out.
At the end of every workday, we sweep the walkway and send you a photo of the clean-up. The Cedarwell Care Promise is in writing and it applies from the first day of demo to the final walkthrough.
Brands We Service
We install and finish ADUs from Abodu, Cover, and Dvele, three of the prefab manufacturers most serious about build quality and California code compliance. Abodu units are engineered around our state’s streamlined ADU permitting path and arrive on-site with appliances and finishes already in place; we handle the foundation, utility connection, and final trim so the unit is move-in ready. Cover builds panelized units with precision-cut wall systems that go up in days and perform beautifully in our dry climate when detailed correctly.
Dvele is our go-to for clients who want a healthier, tighter building envelope with factory-controlled air quality and smart home integration. For exterior cladding, we use James Hardie siding on nearly every unit we build in Los Angeles because it holds paint, resists termites, and meets wildfire-adjacent zone requirements where they apply. If you have a different brand in mind or want help choosing between prefab and stick-built for your specific lot, call (213) 449-7136 and we’ll walk you through the trade-offs in plain language.
Signs You Need a Pro Right Now
- You’ve received a letter from LADBS about an unpermitted unit. A converted garage or unpermitted addition on your property can block an ADU permit, complicate a sale, and trigger fines. We assess what’s existing, what needs to be brought to code, and whether it can be folded into your new ADU scope.
- Your lot has significant slope or drainage problems. Hillside lots in neighborhoods like Echo Park and Sun Valley need engineered retaining and careful grading before any foundation goes in. If water already pools near your house in winter, a poorly planned ADU will make it worse.
- You want to rent the unit and need it legal. Los Angeles is actively enforcing short-term rental and unpermitted unit rules. If you’re planning to rent, the unit must be permitted and meet current building, health, and safety codes, and we can bring it there.
- Your existing electrical panel is maxed out. Most older Los Angeles homes have a 100-amp panel and need an upgrade or subpanel install to support a new ADU. If your lights dim when the microwave runs, you’ll need electrical work scoped into the project before the unit is habitable.
- You’ve been quoted a price without a site visit or written scope. A real ADU price requires a measured survey, a look at your panel, a look at your sewer line, and a written breakdown. If a contractor gives you a number over the phone without seeing any of that, you’re getting a guess, not a price.
Our Process, Step by Step
- 1
Free site walk and measured survey. Ben Ortega or a senior project lead visits your home, measures the lot, checks the electrical panel, locates sewer and water lines, and takes photos. You also get our Cedarwell Care Promise in writing at this visit, so you know exactly how your home will be treated during construction.
- 2
Fixed-price written estimate. Within about a week, you receive a line-item proposal covering design, permits, materials, labor, and any needed utility work. The price we give you is the price we build for; if we find something we missed, we eat it.
- 3
Plan preparation and permit submission. Our design partners draw the plans, our engineer stamps the structural, and we submit to LADBS. We handle every plan checker correction and keep you posted on timing.
- 4
Build phase with daily clean-up. The crew arrives in uniform, protects your floors and walkways with shoe covers and drop cloths, and works around your family’s schedule. You receive a photo of the clean-up before the crew leaves every day.
- 5
Final inspection and the 365-Day Done Right Promise. We schedule final inspections, walk the unit with you, and hand over keys along with your warranty in writing. If anything is not done right within the first year, we make it right.
How Much Does ADU Builders Cost in Los Angeles?
A typical ADU build in Los Angeles runs between $120,000 and $380,000 depending on unit type. A JADU inside your existing home is the lightest lift at $50,000 – $120,000, while a detached backyard ADU with foundation, utilities, and finishes runs $120,000 – $380,000. A garage conversion in Los Angeles usually lands between $90,000 and $200,000, and a full home addition attached to the main house can run $200,000 and up depending on structural work and finish level. These are real ranges for Los Angeles, where soil conditions, permit fees, and LADBS review times keep costs higher than in surrounding counties.
What moves the price: the distance from your sewer lateral to the new unit, whether your existing panel needs an upgrade, whether your lot has slope or drainage issues, and the finish level you choose. What doesn’t move the price: our markup, our design process, or our change order policy. We give you a written, line-item price before any work starts, and no surprise line items get added after crews arrive. To avoid overpaying, get at least two written proposals, check that both contractors are licensed and insured, and compare the scope line by line, not the bottom line. Our free estimate includes the full written scope, so you can use it as a benchmark even if you don’t hire us. Call (213) 449-7136 to schedule yours.
Our Service Area Near Los Angeles
Seedling ADU Los Angeles builds across the entire city and surrounding communities. We regularly work in North Hollywood, Studio City, Los Feliz, Sun Valley, Mar Vista, South Pasadena, Echo Park, El Segundo, Marina del Rey, and Eagle Rock. For most projects, we schedule your site walk within a week of your call and hold a live conversation, not a voicemail tree, when you call with questions. Whether your project is a backyard ADU in South Gate or a garage conversion near the water, our crews arrive in uniform, protect your home, and leave it clean every day. See our home page for more on who we are and how we work across Los Angeles.
Serving Los Angeles, CA - Our Local Coverage Area
We’re Los Angeles ADU Builders who 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 About ADU Builders in Los Angeles
An ADU builder is a licensed general contractor who constructs accessory dwelling units, including detached units, garage conversions, and JADUs, and manages every trade from foundation to final inspection. In Los Angeles, a qualified ADU builder pulls permits, coordinates with LADBS, and delivers a unit that is legal to rent. Call (213) 449-7136 to talk with our team about your specific property.
A typical detached ADU takes 6 to 10 months from first site visit to final inspection, including 2 to 4 months for plan preparation and LADBS review. A JADU inside your existing home can be done in 3 to 5 months because it usually avoids foundation and utility trenching. Your written proposal includes a schedule so you know what to expect before we start. Call (213) 449-7136 for a timeline specific to your project.
In Los Angeles, expect to spend $120,000 to $380,000 for a detached ADU, $50,000 to $120,000 for a JADU, and $90,000 to $200,000 for a garage conversion. Your actual price depends on your lot, your sewer and electrical lines, and your chosen finishes. We provide a written line-item price before any work begins, and that price is the price you pay. Call (213) 449-7136 for a free estimate at your home.
Yes, we install and finish units from Abodu, Cover, and Dvele, and we specify James Hardie siding on nearly every exterior in Los Angeles. We know these brands’ panel details, connection points, and finish tolerances from direct field experience. If you’re considering a different prefab brand, we can help you compare. Call (213) 449-7136 to talk through your options.
During an active build, a live person answers our phone 24/7, so if something goes wrong on the jobsite, you reach a human immediately. For non-emergency projects, we respond to inquiries within one business day. If you have a safety concern during construction, call (213) 449-7136 and we’ll have someone on-site or on the phone right away.
Every Seedling ADU Los Angeles project is covered by our 365-Day Done Right Promise in writing: if it’s not done right, we make it right, covering every ADU, garage conversion, and home addition we build. We also pass along manufacturer warranties on materials like James Hardie siding and prefab components. Call (213) 449-7136 and we’ll walk you through the warranty language before you sign anything.
Plan for a designated crew path, usually a side yard, and keep that area clear of bikes, toys, and pet bowls during work hours. If you have kids, we schedule noisy cutting and hammering around school and nap times where possible. We bring our own shoe covers and drop cloths, use pet-safe products where there’s a choice, and leave a photo of the clean-up before the crew leaves each day. Call (213) 449-7136 to ask any preparation questions before your build begins.
Schedule Your ADU Builders Service in Los Angeles Today
The first step is a free site walk and a written estimate, so you can plan with real numbers instead of guesses. Call (213) 449-7136 to schedule yours with Seedling ADU Los Angeles. You’ll get a live person, a measured look at your lot, and a written price before any work starts. No pressure, no obligations.
Written by Ben Ortega, Owner at Seedling ADU Los Angeles, building accessory dwelling units across Los Angeles with written pricing and the 365-Day Done Right Promise on every job.
