Fast, Reliable Home Addition Contractor Across Commerce
Home addition costs in Commerce, CA typically run $180 – $420 per square foot depending on scope, with a full second-story addition on a 1950s lot usually landing between $140,000 and $285,000. Most Commerce homeowners we work with get a written, line-item price before any crew arrives, and permits move through Commerce’s own planning department rather than LA City or County. If you’re weighing a room addition, bump-out, or full second story, call us at (707) 383-5338 and we’ll walk you through what’s realistic for your lot.
We know Commerce differently than a builder who just drives in from across the county. This city is a small residential pocket of roughly 12,000 people wrapped almost entirely by warehouses, rail spurs, and distribution centers. That changes how we stage a job, how we handle noise, how we pull permits, and how we talk to neighbors. You’ll feel that difference on the first site visit.
Why Seedling ADU Builders Is Commerce’s Preferred Home Addition Contractor Company
Ben Ortega leads our Commerce work, and he’s walked more tight post-WWII lots here than most builders see in a decade. The reason Commerce homeowners keep calling us back is simple: we write the price down before we start, we protect the inside of your home while we build, and we answer the phone when you call. Not a voicemail tree. A person.
Every Seedling project in Commerce carries our 365-Day Done Right Promise in writing. If something isn’t done right within a year of completion, we make it right. No fine print, no argument. That matters when you’re adding a second story over the rooms where your kids sleep.
Our crews arrive in uniform, background-checked, and carrying shoe covers and drop cloths before they touch a doorway. At the end of each workday, you get a photo of the clean-up. That’s our Commerce standard on every job, including home additions. If you’ve had contractors leave a mess or dodge a callback, you’ll notice the difference immediately.
We coordinate scheduling from our Los Angeles office, but the crews who show up in Commerce live and work in this part of LA County. They understand Commerce’s permit desk, its industrial adjacency rules, and its tiny lots. That local knowledge keeps your plan check moving and your neighbors calm.
Room Addition Contractor in Commerce
A Room Addition Contractor in Commerce does more than frame walls. On a 9000-series lot off Gage Avenue or Bandini Boulevard, adding a room means checking setbacks against neighboring industrial parcels, upgrading an undersized electrical panel, and often notifying an adjacent owner before any footing gets dug. It’s a different animal than the same job in Downey or Bell Gardens.
A single ground-floor room addition on a modest Commerce home generally runs $85,000 – $170,000 depending on foundation work, plumbing rough-in, and whether we’re tying into an existing hall or creating a new entry. Homes here date mostly from the 1940s through the 1960s, and we routinely find original galvanized supply lines and 60-amp panels that need replacement before the new space can be energized. We price that in writing before we start, so there’s no surprise line item when the wall opens up.
Foundation and panel work
Most Commerce lots sit on older raised or slab foundations that were never engineered for an addition. We include the structural tie-in in the written price. And if your panel is still at 60 or 100 amps, a 200-amp upgrade is almost always part of the scope, priced up front.
Setback review on industrial edges
If your lot shares a rear or side line with a warehouse or truck yard, Commerce plan check will look at your addition’s placement relative to that industrial use. We handle that review before you ever pay for plans, so you’re not stuck in plan-check limbo for weeks.
Second Story Addition Contractor in Commerce
A Second Story Addition Contractor in Commerce works with the city’s densest constraint: small lots, shared alleys, and neighbors whose industrial access runs right along your property line. We’ve framed second stories here where the rear alley was the only path a neighboring warehouse had to unload trucks. That job took extra staging care, not extra cost surprises.
Second-story additions in Commerce typically run $140,000 – $285,000, and that range moves with structural upgrades, stair placement, and whether we’re lifting the roof or building over an existing wing. On a small lot off Saybrook Avenue near Commerce’s residential pocket, we framed a second-story addition over a 1950s single-story home and kept the rear alley clear the entire time, because it doubled as the neighbor’s only access to their industrial-zoned parcel. Our crew staged materials in a single driveway bay and ran negative-air containment with MERV-13 filtration during demo so dust wouldn’t drift toward the adjoining warehouse.
Party-wall notice and vibration control
When a second story goes up against a shared wall, we submit a party-wall notice to the adjacent owner before we set the shared-wall footing. It’s not optional here. Commerce plan check will flag it, and skipping it can trigger a stop-work order until a survey gets produced.
Structural reinforcement on 1950s framing
Original Commerce framing from the 1940s – 1960s rarely meets current lateral-load requirements for a second story. We include shear-wall retrofits and foundation checks in the written quote, not as a change order halfway through. That’s the Seedling difference: the number on paper is the number you pay.
Trusted Brands We Service in Commerce
We work with the brands Commerce homeowners actually research before calling anyone. If you’re considering a prefab or modular path for your Home Addition Contractor project, we install and finish Abodu and Cover units, and we build with James Hardie siding and trim for the long, hot Commerce summers. We keep local material access through suppliers familiar with Commerce’s permit requirements, so you’re not waiting on a brand rep from another county to sort out a setback question. Pick the product that fits your lot, and we’ll handle the rest.
Common Home Addition Contractor Problems We See in Commerce Homes
- Undersized electrical panels. Most Commerce homes we open up still have 60 – 100 amp original panels. A new addition won’t pass final inspection on that service, so we include the 200-amp upgrade in every quote from day one.
- Industrial adjacency setbacks. Lots backing onto warehouses or truck yards trigger Commerce plan-checker review of addition placement relative to industrial use. We flag that early so your plans don’t stall for weeks.
- South Coast AQMD ventilation rules. Because Commerce sits surrounded by industrial uses, indoor air quality provisions come up in plan check more often than in purely residential cities. We spec mechanical ventilation and filtration from the start.
- Shared rear alleys and tight staging. Many Commerce lots have only a single driveway bay and a shared alley. Blocking the neighbor’s industrial access draws a code enforcement visit. We plan staging before the dumpster ever arrives.
Pricing for Home Addition Contractor in Commerce, CA
Here are the numbers we give Commerce homeowners before any tool is picked up. Ground-floor room additions: $85,000 – $170,000. Second-story additions: $140,000 – $285,000. Sunroom additions: $45,000 – $95,000. Bump-out additions: $60,000 – $130,000. Garage additions: $70,000 – $150,000. Bathroom additions: $40,000 – $85,000. Your exact price shifts with foundation condition, electrical service, and whether industrial-adjacency setbacks change your buildable area. We give you a written line-item quote so you can plan. Call (707) 383-5338 to schedule a free estimate in Commerce.
We Also Serve Cities Near Commerce
Our crews work throughout the eastern LA Basin. Besides Commerce, we bring the same written pricing and daily clean-up to homeowners in Los Angeles, Long Beach, Anaheim, and Riverside. If you’re in a neighboring city and weighing an addition, reach out. We’ll tell you straight what your local permit desk requires.
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 Home Addition Contractor in Commerce
The City of Commerce’s own planning department issues addition permits here, not LA City and not LA County. That means your plans go through Commerce’s plan check, which reviews industrial-adjacency setbacks and South Coast AQMD indoor air quality provisions more closely than most nearby residential cities. We handle that submittal for you. Call (707) 383-5338 and we’ll tell you what your specific lot triggers.
Yes, and often significantly. Commerce plan check will review your addition’s placement relative to the industrial-zoned parcel next to you, including setbacks and AQMD ventilation requirements. That can push your buildable area in from the property line or require mechanical filtration you wouldn’t need in Bell Gardens. We design around it from the first site visit.
Yes, and we’ve done exactly that. The constraint is staging, not feasibility. On a tight Saybrook Avenue lot, we kept the rear alley clear for a neighbor’s industrial access while framing a full second story. We stage in a single driveway bay, run negative-air filtration during demo, and plan every delivery. Call (707) 383-5338 for a free site walk.
Almost certainly not. Most Commerce homes from the 1940s – 1960s still run on 60 – 100 amp panels, and a new addition won’t pass final inspection without a service upgrade. We include the 200-amp panel replacement in our written quote so there’s no surprise once walls are open.
Yes. Commerce plan check expects a party-wall notice before we set a shared-wall footing, and skipping it can trigger a stop-work order until a survey is produced. We prepare and submit that notice as part of our pre-construction work on every shared-wall addition in Commerce.
Ready to get a written price for your Commerce addition? Call Ben Ortega and the Seedling team at (707) 383-5338 to schedule your free estimate. Shoe covers on, drop cloths down, and a clean-up photo before we leave, every day.
Written by Ben Ortega, Owner at Seedling ADU Builders, serving Commerce homeowners with written pricing and the 365-Day Done Right Promise on every addition.