Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
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Before
AfterTrusted Home Additions & ADU for Los Angeles Homeowners
Adding square footage to a Los Angeles home typically costs between $53,100 and $153,400, depending on whether you’re building a detached ADU, converting a garage, or adding a second story. Rowan Construction Group has delivered over 4,000 projects since 2007, every one of them with a written price before work started and a documented record when the crew left. If you’re weighing our Home Additions & ADU in Los Angeles, call (470) 298-9650 and we’ll give you a flat written quote with a written scope, not a verbal ballpark.
Los Angeles zoning for ADUs changed substantially after the state’s 2020 ADU mandate, which forced the city to approve most applications ministerially if they meet objective standards. That means a garage conversion or a junior ADU in neighborhoods like Mar Vista, Eagle Rock, or West Adams is often more feasible now than it was ten years ago. The question is rarely whether you can build. It’s whether the contractor’s number will still be the number when the job is done. Under Clause 1 of The Haven Standard, ours is.
What Our Home Additions & ADU Service Includes
Rowan Construction Group performs seven residential trades under one roof, and Home Additions & ADU - Huntington Park is one of them. Each project starts with a written price and a written scope, then moves through permitting, foundation, framing, mechanicals, finishes, and a documented photo record at every visit. Here’s what that looks like in practice.
ADU Design & Permitting
An ADU, or accessory dwelling unit, is a self-contained living space on the same lot as a primary residence. It has its own kitchen, bathroom, entrance, and address. When you need one, it’s usually because a mortgage payment or an aging parent made extra square footage more economical than moving. Rowan handles the design, the D-2 submittal to LADBS, and the plan checks, using drafting partners who know Los Angeles zoning well enough to flag a setback problem before it costs you a permit resubmittal.
Garage Conversion ADU
A garage conversion turns an existing attached or detached garage into living space, and it’s the most common ADU type in Los Angeles because it avoids foundation over-excavation and most new utility trenching. You need this when the garage is housing boxes rather than cars and the house is short a bedroom or an income unit. Rowan starts by documenting the condition of the slab, the framing, and the existing electrical panel, because a 1970s garage in the Valley rarely has a panel rated for a kitchen and a mini-split.
New Detached ADU
A new detached ADU is a ground-up structure, typically 400 to 800 square feet, built in the rear yard. You need it when the garage is inaccessible, the setbacks allow a separate footprint, or you want rental income with a true separate address. Rowan’s scope includes site prep, foundation, framing, rough and finish trades, and a documented photo record at each inspection milestone so you can see the progress without being on site.
Junior ADU & Interior Conversion
A junior ADU, called a JADU under California law, is a conversion of up to 500 square feet within an existing home, often a primary bedroom with an efficiency kitchen. It’s the lowest-cost ADU path and the fastest to permit in Los Angeles. Rowan handles the wall assembly, the egress window, the kitchenette plumbing, and the separate entrance requirement, which is the detail that most often fails a JADU inspection.
ADU Site Prep & Utilities
Before framing starts, the site has to be cleared, graded, and trenched for utilities. In Los Angeles, that often means hitting a 50-year-old clay sewer line or a root-bound gas lateral under a mature camphor tree. Rowan’s site prep scope includes utility locating, trenching, backfill, and concrete or raised pier foundation work, with the existing conditions photographed and documented before any dirt moves.
Room Additions
A room addition extends the primary home’s envelope, typically a family room, a primary suite, or a home office. You need it when the house works but lacks one room that would change how you live in it. Rowan’s room addition scope covers the foundation tie-in, the roof intersection, the HVAC extension, and the drywall and paint, with the same flat written price applied to the whole job.
If the addition involves touching a load-bearing wall, moving a panel, or altering roof structure, the permit drawings will require an engineer’s stamp. We coordinate that, and the line item appears in the written scope before you sign anything.
What happens when you call
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A real person answersNo phone trees - you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Brands We Service for Home Additions & ADU
We’ve framed and finished work around manufactured ADU systems from Abodu and Cover, both of which ship panelized or modular units to Los Angeles lots. With an Abodu unit, the foundation and utility connections happen on site while the shell is built in a factory, which compresses the schedule but demands tighter site prep tolerances. Rowan crews have set the foundation elevations and stub-outs for these units, and we document the exact bearing points before the module arrives.
We’ve also seen Dvele and Mighty Buildings specified on Los Angeles projects, particularly when a homeowner wants a tight building envelope or a shorter framing cycle. A Dvele unit arrives with integrated sensors and mechanicals that have to be commissioned, not just connected. Whether you have one of these brands on order or you’re building a site-framed ADU from scratch, the number we give you is the number in the contract.
BeforeAfterSigns You Need Home Additions & ADU Right Now
- Your household size changed but your square footage didn’t. A second child, a returning parent, or a full-time remote job turns a two-bedroom into a scheduling problem. Adding 400 square feet is often cheaper per square foot than selling and buying at today’s Los Angeles prices, and an ADU keeps the move off the table.
- You’re pricing a move and it doesn’t pencil out. If you bought between 2015 and 2025, your property tax basis is probably lower than anything you’d pay on a replacement home. A $120,000 addition may cost less than the transfer taxes, commissions, and higher interest rate on a new purchase.
- Your garage is dead space. In Los Angeles, a 400-square-foot garage conversion returns roughly $3,500 to $4,200 per month as a long-term rental in many neighborhoods, according to current market listings. That’s a better cap rate than most other home improvements.
- You’ve had contractors give you a number that moved later. A verbal estimate that grows by 18 percent after demo is not an estimate; it’s an opening bid. If that’s happened to you, request a written scope and a flat price before any work starts, and ask the contractor to put the change-order rule in writing.
- Your lot has the room but the house doesn’t. A 5,000-square-foot Los Angeles lot can often legally hold a detached ADU even with an existing garage, under the city’s current ADU ordinance. If the roof plan and the rear yard both have space, the question is permitting, not possibility.
Our Home Additions & ADU Process - Step by Step
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Written estimate and scope review. We walk the property, measure the existing conditions, and document what’s there before we price it. You get a flat written price, a written scope of work, and a written warranty. No verbal ranges, no “we’ll figure it out as we go.”
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Permit drawings and submittal. Our drafting partners prepare the plans and we submit them to LADBS. If a structural engineer’s stamp is required, it’s listed as a line item before submittal. We don’t start a permit without confirming the fee schedule with you in writing.
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Site prep and foundation. Once the permit is issued, we handle demolition if needed, then excavation, utility trenching, and foundation work. Before any concrete is poured, we photograph the forms, the rebar spacing, and the soil condition. That photo record is yours, regardless of whether you’re on site.
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Framing, mechanicals, and finishes. Our crews handle the trade work, and any subcontractor on the job is background-checked and uniformed. If a change is required mid-project, a change order is written and signed before the work proceeds. Nothing gets done on a handshake.
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Inspection and closeout. We walk the project with you, complete the punch list, and hand over the documented photo record, the final inspection sign-offs, and the warranty in writing. The 365-Day Done Right Promise is printed on every contract, and it means if it’s not done right, Rowan makes it right.
How Much Does Home Additions & ADU Cost in Los Angeles?
A home addition in Los Angeles typically runs $53,100 to $153,400. A detached ADU runs $106,200 to $259,600. A garage conversion runs $35,400 to $94,400. Those numbers include Rowan’s flat written price, not a low opening bid that grows later.
What moves the number? Square footage first, then foundation conditions, then utility runs, then finish level. A 400-square-foot garage conversion on an existing slab with a panel that’s already rated for the load will sit near the low end. A 750-square-foot new detached ADU with a long sewer run, a new 200-amp subpanel, and mid-range finishes will sit near the high end. If the site is on a hill, add for pier work or retaining considerations.
To avoid overpaying, get the price in writing before demo. If a contractor won’t put the full scope on paper, the number isn’t real. Ask whether change orders must be signed before work proceeds. Ask for the warranty in writing. And bring us any written estimate from another Los Angeles contractor. Our Free Second Opinion means we’ll review it line by line at no charge, and tell you honestly whether the number is fair, low, or padded.
Home Additions & ADU Near Los Angeles - Our Service Area
Rowan Construction Group serves homeowners throughout the Los Angeles metro, from the Westside to the Valley to the San Gabriel foothills. We’re also home to full-service residential construction across multiple cities. Our written-price system is the same whether the project is in Los Angeles, Home Additions & ADU in Houston, or Home Additions & ADU in San Antonio. The cost of labor and materials shifts by market, but the discipline doesn’t.
If you’re in San Diego, Dallas, San Jose, Austin, Jacksonville, San Francisco, Fort Worth, Fresno, or Sacramento and considering an addition, contact us. We’ll confirm service availability and give you a written price before any work starts.
Serving Los Angeles, CA - Our Local Coverage Area
We’re based in the Los Angeles area and know this community well, including Home Additions & ADU in South Gate. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
Frequently Asked Questions - Home Additions & ADU in Los Angeles
A home addition is new square footage attached to or integrated with your existing house; an ADU is a self-contained dwelling unit with its own kitchen, bathroom, and entrance on the same lot. In Los Angeles, ADUs are regulated by state law and the LADBS, and most are approved ministerially if they meet objective standards. Call (470) 298-9650 and we’ll tell you which path fits your lot and your budget.
A garage conversion ADU typically takes 4 to 7 months from permit submittal to final inspection; a new detached ADU typically takes 7 to 12 months. The biggest variable in Los Angeles is not construction, it’s the LADBS plan check queue, which can run 6 to 12 weeks depending on the current workload. We’ll give you a written schedule with your written price.
A home addition runs $53,100 to $153,400; a garage conversion runs $35,400 to $94,400; a new detached ADU runs $106,200 to $259,600. Your exact number depends on square footage, site conditions, utility runs, and finishes. Call (470) 298-9650 for a flat written quote, not a range with an asterisk.
Yes. We’ve set foundations, utility stubs, and connections for Abodu and Cover units, and we’re familiar with Dvele and Mighty Buildings specifications. If you’ve ordered one of these units, we’ll coordinate our site work with the factory schedule and give you a written price for the on-site portion.
Home additions and ADUs are planned construction, not emergency work, so we schedule them in sequence with a written timeline. That said, a live person answers our phones 24/7, and we can usually get a site walk on the calendar within a week. Call (470) 298-9650 and we’ll set it up.
Every project includes the 365-Day Done Right Promise: if it’s not done right, Rowan makes it right. The warranty language is printed in the contract, not referenced by a vague “we stand behind our work.” We also include a documented photo record of every visit so you have evidence of what was done.
Gather your property survey if you have it, note the age of your electrical panel, and take photos of the areas you want to change. If you have an existing estimate from another contractor, bring it. We’ll review it line by line at no charge, then give you our own written price so you can compare the actual scopes. Call (470) 298-9650 to schedule the walk-through.
Schedule Your Home Additions & ADU Service in Los Angeles Today
Get a written price for your Home Additions & ADU - Bell before anyone picks up a tool. Call (470) 298-9650 for a flat written quote, a written scope, and a written warranty. No obligation, no verbal ballparks, no number that moves after demo. That’s the whole point.
Written by Grant Rowan, Owner at Rowan Construction Group, building under The Haven Standard since 2007.