Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
Before
After
Before
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Before
AfterTrusted Home Additions & ADU for Los Angeles Homeowners
Most Los Angeles homeowners who call us about an ADU or room addition bought their house between 2015 and 2022, paid more than they planned, and now need square footage without the moving costs of a $1.2 million comparable. We’ve built our Home Additions & ADU in Los Angeles since 2007, completing over 4,000 projects with a written price delivered before any work started and a documented photo record when the crew left. Under Clause 1 of The Haven Standard, the number you agree to is the number you pay, kept within a few percent across every trade we operate. Call (213) 652-7670 to schedule your free estimate.
What Our Home Additions & ADU Service Includes
ADU Design & Permitting
An accessory dwelling unit starts with a set of plans that satisfies LADBS and, depending on your lot, the California Department of Housing and Community Development’s SB 9 and SB 13 guidelines. You’ll need this service when you’re converting underused garage space or building new, because Los Angeles processes roughly 15,000 ADU permits annually and a rejected submittal costs six to ten weeks. At Rowan Construction Group Los Angeles, we produce construction documents in-house, coordinate structural calculations for hillside lots in areas like Laurel Canyon and Mount Washington, and track the permit through plan check so you’re not the one sitting on hold with the city.
Garage Conversion ADU
A garage conversion ADU reclaims existing footprint, which in Los Angeles often means a 400-square-foot structure with a sloped slab and no existing insulation against the ceiling. You need this when your garage stores nothing but holiday decorations and your property’s floor area ratio still has headroom under the zoning code. We assess the slab for moisture intrusion, sister any rafters that won’t carry R-38 insulation weight, and run new electrical service from the main panel, because most pre-1980 garages in Los Angeles operate on a single 15-amp circuit that cannot support a kitchenette and mini-split.
New Detached ADU
A new detached ADU is a ground-up structure, typically 400 to 1,200 square feet, on a foundation separate from the primary residence. This makes sense when your lot has rear yard access and you want rental income or dedicated space for family without sharing walls. We handle the full build in Los Angeles, from soils report and spread footings on clay-heavy lots in the Westside to fire-rated separation when the ADU sits within five feet of the property line, which triggers California Building Code Chapter 7A requirements. See also Home Additions & ADU in Culver City.
Junior ADU & Interior Conversion
A Junior ADU, or JADU, is carved from existing living space inside the primary residence, limited to 500 square feet with an efficiency kitchen and exterior door. You’ll pursue this when your Los Angeles home has a large primary bedroom, a converted basement in older hillside construction, or a wing that’s been underused since children left. We install the required separate entrance, add a wet wall for the kitchenette, and ensure the JADU maintains fire separation from the main unit, because Los Angeles requires a 1-hour rated assembly between occupancies.
ADU Site Prep & Utilities
Site prep and utilities cover everything between permit issuance and foundation pour: demolition, grading, trenching for sewer lateral and water service, and electrical upsizing. In Los Angeles, this phase uncovers the most surprises, especially on 1920s lots in Silver Lake or Echo Park where sewer lines are terra cotta and water mains are 3/4-inch galvanized. We photograph every utility exposure, document the condition in writing, and if the main panel needs upgrading from 100 to 200 amps, that scope is priced and signed before the trench is backfilled.
Room Additions
A room addition extends the primary residence, whether that’s a master suite, family room, or expanded kitchen footprint. For nearby options, see our Home Additions & ADU in Inglewood. Los Angeles homeowners typically pursue this when they’ve maxed out interior reconfiguration and need square footage that flows with the existing floor plan. We match the new foundation to the existing stem wall, replicate or upgrade the roofline so the addition doesn’t read as an afterthought, and specify matching siding or stucco finish, because a room addition that looks tacked on hurts resale value in competitive neighborhoods like Los Feliz or Atwater Village.
Second Story Additions
A second story addition doubles your vertical square footage without sacrificing yard space, common in Los Angeles neighborhoods where land values in Venice or Mar Vista make footprint expansion uneconomical. You need structural verification that your existing foundation and first-floor walls can carry the load, which often requires a structural engineer’s letter and potential underpinning. We coordinate that analysis, manage the temporary weather protection during framing, and sequence the work so you’re not living under tarp for three months.
Sunrooms & Enclosed Patios
Sunrooms and enclosed patios convert outdoor living space into conditioned year-round rooms, typically with aluminum or vinyl window walls and a dedicated HVAC zone. In Los Angeles, where the distinction between indoor and outdoor living blurs from April through November, this is often the most used square footage in the house. We specify low-E glazing oriented west for afternoon sun exposure, integrate the roof with existing fascia, and run a dedicated mini-split or extend ductwork, because a sunroom that relies on a portable heater becomes a storage room by January.
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 worked with prefabricated ADU systems from Abodu, completing foundation prep and utility tie-ins for their standard 340- and 610-square-foot modules across Los Angeles lots where speed of enclosure matters. Abodu’s units arrive weather-tight, which means our site work and their crane-set schedule have to align precisely; we coordinate that sequence and handle any field modifications for hillside foundations or non-standard setbacks. For homeowners considering Cover’s design-build platform, we serve as the local construction partner, executing their engineered plans on site and managing the relationship with LADBS so the digital permit package translates to actual inspected work.
We’ve also built with Dvele’s smart-home-integrated modules and Mighty Buildings’ 3D-printed polymer composite units, both of which require specific foundation tolerances and electrical rough-in schedules that differ from stick-built construction. With Dvele, we coordinate the low-voltage prewire before module delivery; with Mighty Buildings, we manage the crane pick and the specialized sealants at panel joints. Whether you have Abodu, Cover, Dvele, Mighty Buildings, or any other make, we can help. Our quote includes the written scope, the written timeline, and the written price before anyone picks up a tool.
Before
AfterSigns You Need Home Additions & ADU Right Now
- Your household has grown but your square footage hasn’t. A second child, an aging parent, or adult children returning home creates immediate pressure on bathrooms, storage, and privacy. In Los Angeles, where median home prices have doubled since 2012, moving to a larger house often costs $500,000 more in mortgage principal alone, making an ADU or room addition the financially rational path.
- You’re paying rent elsewhere for workspace or family housing. If you’re leasing a studio in Culver City for a grown child or maintaining an office in a commercial building while your garage sits empty, you’re subsidizing someone else’s mortgage. An ADU converts that monthly outflow into equity in your own property, with rental income potential that in Los Angeles averages $2,200 to $3,800 monthly depending on neighborhood and size.
- Your garage or basement is structurally sound but functionally useless. Water-stained drywall, a cracked slab with no vapor barrier, or a basement that floods in January rains means the space is deteriorating while it sits idle. Converting it now prevents further degradation and captures the value before Los Angeles’ seismic retrofit requirements add mandatory costs to any structural work.
- Your property’s zoning changed under state law but you haven’t acted. SB 9 and SB 13 removed many of the local barriers that previously blocked ADU construction in Los Angeles, including parking requirements and owner-occupancy rules. These laws are not permanent guarantees; municipalities continue to challenge implementation, and acting while the pathway is clear avoids future restriction.
- You need rental income to offset a recent mortgage adjustment. Los Angeles homeowners who bought at 3% and now face 7% on a refi or HELOC are searching for cash flow. An ADU at $150,000 to $250,000 construction cost, financed over 30 years, typically generates positive monthly cash flow against the debt service, a calculation we include in your written estimate if income projection is relevant to your decision.
Our Home Additions & ADU Process - Step by Step
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Site Visit and Written Assessment - We walk your Los Angeles property with a laser measure, assess access for equipment, and photograph existing conditions including utility locations, slope, and any structures within setback distances. Within 48 hours, you receive a written summary with preliminary feasibility and a price range, not a verbal guess.
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Design Development and Permit Package - For projects requiring architectural plans, we produce or coordinate construction documents, structural calculations, and Title 24 energy compliance. We submit to LADBS or the relevant local jurisdiction and track the plan check cycle, responding to corrections without passing the administrative burden to you.
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Fixed-Price Quote and Signed Agreement - Under Clause 1 of The Haven Standard, you receive a flat written price with line-item scope, material specifications by brand and model where selected, and a written warranty. No work proceeds until you sign. If you have a competitor’s written estimate, we will review it line by line at no charge.
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Construction with Documented Progress - Our background-checked, uniformed crew executes the build with a photo record uploaded after every visit. Change orders, if needed, are written, priced, and signed before the altered work begins. This discipline is why our projects finish within a few percent of the agreed price across 4,000-plus jobs since 2007.
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Final Inspection and 365-Day Done Right Promise - We coordinate all inspections, correct any punch-list items immediately, and deliver your final documentation including permit sign-off, photo archive, and warranty terms. If anything is not done right, we make it right under The Haven Standard, backed by a terms page you can reference, not a handshake.
How Much Does Home Additions & ADU Cost in Los Angeles?
A typical home addition in Los Angeles runs $53,100-$153,400 depending on whether you’re adding 200 square feet of master bedroom or 800 square feet of ground-floor living space with full kitchen and bath. ADU construction, which includes standalone kitchens, bathrooms, and separate utility services, ranges from $106,200-$259,600. Garage conversions fall between $35,400-$94,400, with the lower end representing a studio ADU with minimal plumbing and the upper end a one-bedroom with full kitchen, stackable laundry, and upgraded finishes.
Several factors move the price within these ranges. Foundation type matters: a slab-on-grade in flat Los Feliz costs less than drilled piers on a hillside lot in the Hollywood Hills. Utility distance from the main house affects trenching and electrical upsizing. Finish level is significant; a garage conversion with IKEA cabinetry and vinyl plank floors sits at the low end, while Cambria countertops and Kohler fixtures move the number up. Permit fees in Los Angeles add $3,000-$12,000 depending on valuation and whether school fees apply.
To avoid overpaying, get a written scope that specifies material brands, not generic descriptions like “tile” or “cabinets.” Compare line items, not just bottom lines, a competitor’s quote that omits the electrical panel upgrade will cost you that amount later as a change order. Our written estimate includes every foreseeable cost; if we miss something, we absorb it. The quote is free, the scope is detailed, and the price is fixed.
Home Additions & ADU Near Los Angeles - Our Service Area
We build across Los Angeles and the immediate Westside, including Home Additions & ADU in Culver City, Home Additions & ADU in West Los Angeles, Santa Monica, Venice, Beverly Hills, Westchester, Brentwood, West Hollywood, Inglewood, Studio City, and Manhattan Beach. Typical response time for an initial site visit is three to five business days. For properties in the coastal zone or historic preservation overlay zones, we coordinate the additional review layers during design so they don’t extend your timeline unexpectedly.
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.
Frequently Asked Questions - Home Additions & ADU in Los Angeles
A home addition expands your primary residence, while an ADU, or accessory dwelling unit, is a separate living space with its own kitchen, bathroom, and entrance. You need an addition when you want more space integrated with your existing floor plan; you need an ADU when you want rental income, separate family housing, or a home office with legal occupancy status. Call (213) 652-7670 and we’ll assess your lot, your zoning, and your goals to recommend the right path.
Permit timeline is typically four to six months for an ADU in Los Angeles, and construction adds four to eight months depending on size and complexity. A simple garage conversion ADU can be complete in six to eight months total; a new detached ADU with custom finishes often takes twelve to fourteen months. We provide a written timeline with your quote, updated monthly, so you know where the project stands without calling for status.
ADU construction in Los Angeles costs $106,200-$259,600, with garage conversions at $35,400-$94,400 and room additions at $53,100-$153,400. The final number depends on foundation requirements, utility distance, finish specifications, and whether your lot requires hillside engineering or retaining walls. Call (213) 652-7670 for an exact quote - estimates are free, written, and itemized.
Yes, we are an approved local construction partner for Abodu, Cover, Dvele, and Mighty Buildings, handling site prep, foundation, utility tie-ins, and finish work that the manufacturer doesn’t cover. We also build entirely custom stick-frame ADUs if prefabricated dimensions don’t fit your lot or aesthetic. Bring any manufacturer’s quote and we’ll review it against a site-built alternative at no charge.
We do not perform emergency dispatch for planned construction; ADUs and additions are scheduled projects with permit and design lead times. If you discover structural damage during demolition, such as compromised foundation or unpermitted prior work, we assess within 24 hours and issue a written change order with revised scope and pricing before proceeding. For genuine emergencies like storm damage or collapse, our live answering service routes you to the appropriate response team.
Every addition and ADU carries our 365-Day Done Right Promise: if it is not done right, we make it right, backed by The Haven Standard terms page, not an asterisk. This covers workmanship, material installation, and functional performance of systems we install. Manufacturer warranties on products like windows, roofing, or appliances run separately and are transferred to you at completion.
Gather any existing surveys, previous permits, or architectural plans for your Los Angeles property; if you don’t have them, we can order a current survey. Note any specific needs, such as accessibility requirements, rental income targets, or timeline constraints. We’ll handle the rest during the site visit, including feasibility assessment, preliminary zoning analysis, and a written price range delivered within 48 hours.
Schedule Your Home Additions & ADU Service in Los Angeles Today
Call (213) 652-7670 to schedule your free estimate. You’ll receive a written price before any work starts, a documented photo record on every visit, and the 365-Day Done Right Promise backed by The Haven Standard. Our live answering service is available 24/7, and Grant Rowan or a senior project manager will return your call within one business day to confirm your appointment.
Written by Grant Rowan, Owner at Rowan Construction Group, serving Los Angeles since 2007.