A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateFast, Reliable Room Addition Contractor Across Commerce
Room additions in Commerce typically cost between $180 and $320 per square foot, with most projects landing between $55,000 and $140,000 depending on scope, foundation work, and the condition of the existing home. We’re Fielding ADU Los Angeles, and our crews know Commerce’s older housing stock well. The homes here – mostly 1940s through 1960s wood-frame stucco on compact lots – come with specific challenges you won’t find in newer suburbs. When you call (213) 732-1415, a live person answers. Not a voicemail. Not a callback queue. You’ll get straight answers about what adding a room to your Commerce home actually takes.
Why Fielding ADU Los Angeles Is Commerce’s Preferred Room Addition Contractor
We work under The Garrison Standard, a set of operating rules set by our parent company Garrison Partners, which has been building to this standard since 2006. The rules are simple, and they’re written down: show up in the window, put the price in writing before work starts, build by the book, leave the site clean, and stand behind the work for a full year. That last part is The 365-Day Done Right Promise. If something fails inside that year, we return and correct it at no charge. Reed Calloway leads our team, and he holds every project in Commerce to that same written guarantee.
Commerce homeowners who call us get three things most contractors in Southeast Los Angeles won’t put on paper. First, a written price before any work starts. The number you approve on day one is the number on the final invoice. Second, background-checked, uniformed crews on every job, so you know exactly who’s on your property. Third, a live person answering the phone 24 hours a day, 7 days a week. No answering service. No “leave a message.” If you call at midnight with a question about your Commerce addition, someone picks up.
ADU Conversion in Commerce
ADU Conversion in Commerce is often the smartest path for homeowners on lots where a detached structure already exists – especially those long, narrow driveways leading to rear garages that define so much of this city’s housing stock. In Commerce, a small, densely built city where single-family homes sit alongside light industry, ADUs are less about spacious backyard cottages and more about squeezing usable units into tight, irregular lots. The city’s pro-business permitting approach – shaped by its industrial tax base and the ongoing need for workforce housing – makes it one of the more ADU-friendly cities in this part of Los Angeles County. But that friendliness comes with specific setback rules, parking waivers near transit corridors, and height limits that reflect Commerce’s compact, semi-urban character.
Attached Garage Conversions
Many Commerce homes built in the 1950s and 1960s have attached garages that don’t actually fit modern vehicles. Converting one into a primary bedroom suite, a family room, or a rental unit usually runs $45,000 to $95,000. The work involves upgrading the slab, reframing the garage door opening, running new electrical, and insulating to current Title 24 standards. Our Room Addition Contractor team handles the structural and permitting work from start to finish.
Detached Garage ADUs
Those rear-lot detached garages in Commerce are prime ADU candidates. A full conversion typically runs $85,000 to $160,000 before permit fees, depending on whether you keep the existing shell or rebuild. One detail that helps in Commerce specifically: some residential lots sit directly adjacent to light-industrial parcels, which means a homeowner can sometimes tap into commercial-grade utility connections. That can speed up electrical permits and reduce the cost of a heavy-up, because the feeder capacity is already there.
Sunroom Builders in Commerce
Sunroom Builders in Commerce need to account for a specific local condition: this city’s inland location means summer temperatures regularly climb past 90°F, and a poorly insulated sunroom becomes an oven by mid-afternoon. A properly built sunroom in Commerce – one with low-E glazing, adequate ventilation, and a conditioned air supply – typically runs $28,000 to $65,000 for an attached three-season room, and $55,000 to $95,000 if you want a four-season build that ties into the home’s HVAC. We spec glazing and insulation for Commerce’s hot, dry summers and cool, wet winters, not a generic Southern California average.
Prefab Sunroom Systems
For homeowners who want a faster build with fewer variables, we work with leading prefab platforms including Abodu, Cover, and Dvele. These systems pair well with Commerce’s small lots, because the module arrives pre-engineered and goes up in weeks rather than months. A prefab sunroom or attached studio in Commerce typically lands between $65,000 and $120,000 installed, depending on foundation requirements.
Conventional Stick-Built Sunrooms
If you prefer a custom footprint – say, wrapping around an existing corner of a 1950s ranch on a street off Eastern Avenue – conventional framing with James Hardie siding gives you full control over dimensions and finish. We write the price before cutting anything, so you see the full scope on paper first.
Trusted Brands We Service in Commerce
We’re fluent with the platforms Commerce homeowners are already researching online. We build and install structures from Abodu, Cover, and Dvele, and we spec James Hardie siding on conventional builds where it matches the home’s character. Working with us means your crew in Commerce already knows these systems cold – no learning curve on your project, no “we’ll figure it out when it arrives,” and local parts coordination so a missing bracket doesn’t stall your schedule for two weeks.
Common Room Addition Contractor Problems We See in Commerce Homes
- High water table and slab moisture. Parts of Commerce sit on the Los Angeles Basin’s alluvial plain with a high water table. We’ve seen addition slabs poured without vapor barriers, and within a year the new framing is wicking moisture. Our standard spec includes a proper barrier and, where needed, a perimeter drainage swale.
- Cloth-wrapped wiring from the 1940s and 1950s. Opening a wall in an older Commerce home frequently reveals original cloth-insulated conductors that have been spliced multiple times. The city triggers an electrical correction when you permit the addition, and we write that allowance into the contract before we open a single wall.
- Seismic retrofits triggered by wall removal. When a connected older wall comes out to make room for a new addition, Commerce’s building code can require retrofitting the adjacent cripple wall or foundation connection. Contractors who quote without checking this end up moving the price mid-job. We check it during the estimate.
- Undersized subpanels. Because some Commerce residential lots are zoned adjacent to light-industrial parcels, the utility feed can be heavier than typical single-family service. That’s an opportunity, not a problem – unless the contractor specs a box that’s too small and the addition fails inspection. We verify the actual feed before we quote.
Pricing for Room Addition Contractor in Commerce, CA
A room addition in Commerce runs $180 to $320 per square foot. The low end applies to simple bump-outs on a level lot with clean access. The high end covers second-story builds, foundation work where the water table is a factor, and full electrical service overhauls. What moves a Commerce quote more than anywhere else in Southeast LA: the age of the wiring, the condition of the slab, and whether seismic retrofits trigger. We handle all of this with a written allowance system. If we find a condition inside the wall that no one could have known about, the price to fix it is pre-approved in writing – you see it before we touch it. Call (213) 732-1415 for a free estimate. The number you get is the number you’ll see on the final invoice.
A note on foundation costs specifically: Commerce’s high water table in certain pockets means our quotes often include $3,000 to $8,000 more for drainage and vapor protection than a comparable quote in, say, Gardena or West Hollywood. That’s not markup. That’s building a slab that won’t wick moisture into your new bedroom walls six months after move-in.
We Also Serve Cities Near Commerce
Beyond Commerce, we serve homeowners across Room Addition Contractor in Commerce and the surrounding Southeast Los Angeles area, including Los Angeles, West Hollywood, Beverly Hills, and Gardena. Scheduling and dispatch are coordinated from our Los Angeles office; crews are dispatched locally to Commerce every weekday. If you’re in a neighboring city and considering an addition, the same written-price-first standard applies.
Serving Commerce, CA - Our Local Coverage Area
We’re based in the Commerce 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 Room Addition Contractor in Commerce
Yes. When you open walls in a Commerce home with original cloth-wrapped wiring, the city requires the exposed electrical to be brought current before inspection. We pull this permit as part of the overall addition scope, write the expected cost in as an allowance, and get your written approval before opening the wall. Call (213) 732-1415 and we’ll walk you through what your home’s wiring age means for the quote.
A bedroom above a detached garage is treated as a second story, which in Commerce means stricter height and setback limits apply. Some rear-lot garages can accommodate it; many cannot without a variance. We check the specific lot’s zoning before you commit to the design. Call (213) 732-1415 for a free estimate, and we’ll look at your specific address rather than speaking in generalities.
Commerce sits partly on the LA Basin’s alluvial plain, where the water table is higher than in adjacent cities like Beverly Hills or West Hollywood. That means slabs need enhanced vapor barriers, and in some pockets, drainage swales or raised stem walls. The extra $3,000 to $8,000 is the cost of building correctly here, not a contractor padding the quote.
It can. Residential parcels directly adjacent to light-industrial parcels in Commerce sometimes have access to heavier utility feeds than a typical single-family home. That means your panel upgrade may need to be larger – or, in some cases, can be smaller because the capacity is already at the meter. We verify the actual feed during the estimate so the panel spec matches what the city will inspect. Call (213) 732-1415 and we’ll check your address.
Commerce offers parking waivers near transit corridors for accessory dwelling units and certain room additions that add a bedroom. Whether your specific address qualifies depends on its distance from transit and the existing parking configuration on the lot. We handle this verification as part of the permit package. For an exact answer on your street, call (213) 732-1415 – estimates are free, and we’ll check the local ordinance for your address.
How We Handle What’s Inside Your Commerce Walls
Here’s the thing about adding a room to a 1950s Commerce home: the quote you approve before we open a wall is only as honest as the allowances behind it. We’ve done enough of these to know what hides inside. Original cloth-wrapped wiring spliced six times. Foundation slabs with hairline cracks from the high water table. Framing that was undersized even in 1955 and has only gotten softer. The reason most remodel quotes in Commerce move mid-job is that the contractor either didn’t know these conditions existed or didn’t want to scare you with the truth at the estimate stage.
We do it differently. On Eastern Avenue near the Citadel Outlets, our crew converted an attached 1950s garage into a primary-bedroom suite. Opening the walls revealed original cloth-wrapped wiring that had been spliced multiple times and a rear foundation slab with hairline cracking from the high water table. We pulled a permit for a full electrical overhaul and added a perimeter drainage swale, then wrote both into the contract as pre-approved allowances before touching anything. The owner saw the exact numbers before we opened the wall. That’s how every Commerce project runs under Reed Calloway’s supervision.
This approach is the spine of how we work in Commerce. Inspection comes first. Allowances are written into the contract, not discovered at the door. Any surprise is priced and approved in writing before we touch it. That means the number you approve at the start is the number on the final invoice, and everything in between is documented on paper.
If you’re considering a room addition in Commerce, ADU conversion, or a sunroom on one of the city’s compact lots, call (213) 732-1415. You’ll reach a live person. We’ll schedule a free estimate, inspect what’s actually in your walls and under your slab, and put a written price in your hands before any work starts.
Written by Reed Calloway, Owner at Fielding ADU Los Angeles, serving Commerce and the surrounding Southeast Los Angeles area under The Garrison Standard.
