Fast, Reliable Home Addition Contractor Across Westmont
Home additions in Westmont run $180 – $420 per square foot for typical room additions, with a 400-square-foot project landing between $72,000 and $168,000 depending on finishes, foundation work, and whether you’re going through the LA County permitting process. That’s the honest range we quote before any work starts. Lodgewick ADU Builders has been handling home additions and ADU projects since 2010, and we know Westmont’s unincorporated LA County permitting pathway better than most contractors in the LA Basin. Call (254) 602-5618 for a written, no-surprise estimate on your project.
Why Lodgewick ADU Builders Is Westmont’s Preferred Home Addition Contractor Company
Westmont homeowners don’t call us because we’re the biggest name around. They call because we write down the price, show up in the window we gave, and put our 365-Day Done Right Promise in writing on every project. If the work isn’t right, we come back and make it right. That’s The Kingswell Way, named for the family that founded this company in 2010, and it’s how our Home Addition Contractor team operates on every Westmont job, from a small bump-out to a full second-story addition.
Our background-checked, uniformed crews serve Westmont directly, coordinated from our Los Angeles office. When a Westmont homeowner calls, a live person answers, 24/7. No voicemail loops. No chatbots. Just someone who can talk you through what a room addition will actually cost and how long county plan check will take.
What matters locally: Westmont is unincorporated. That means every permit runs through LA County Building and Safety (LACBS) and the Department of Regional Planning, not a city hall counter like Inglewood or Gardena. We front-load complete, county-formatted submittal packages so plan check doesn’t stall. That local knowledge is why Westmont homeowners call Lodgewick before they call anyone else.
Room Addition Contractor in Westmont
A Room Addition Contractor in Westmont handles ground-level expansions: a new bedroom, a family room off the back of the house, or a home office built onto an existing ranch. In Westmont’s compact 1940s – 1960s tracts off Western Avenue and W 112th Street, these projects typically mean working with wood-frame construction on modest lots. A ground-level room addition in Westmont runs $180 – $320 per square foot, so a 300-square-foot bedroom addition lands between $54,000 and $96,000. Permitting goes through LACBS, and we handle the full submittal.
What to Expect on Your Lot
Westmont lots are tight. Many homes sit on 5,000 – 7,000-square-foot parcels, which means setback requirements drive the design. We measure first, design within the county’s rear and side yard limits, and give you a written price before anything goes to plan check.
Foundation and Seismic Requirements
Because Westmont sits in the LA Basin’s seismic zone, any new foundational work must meet California’s current detailing standards. If your home is a post-WWII wood-frame build, we confirm the existing foundation can handle the tie-in before we pour anything new. That prevents a plan-check rejection that costs weeks.
Second Story Addition Contractor in Westmont
A Second Story Addition Contractor in Westmont builds upward: adding bedrooms, a primary suite, or a whole upper floor to an existing single-story home. This is the smart play on small lots where there’s no yard to expand into. In Westmont, second-story additions run $280 – $420 per square foot, so a 500-square-foot upper-floor addition typically costs between $140,000 and $210,000. That includes structural engineering, county plan check, and seismic detailing.
Structural Reality Check
Not every 1950s Westmont ranch is framed to carry a second story. We check the existing wall framing and foundation first, before you spend a dollar on design. If the structure needs reinforcement, we tell you exactly what that costs in writing. No surprises after framing starts.
Working With Your Home’s Bones
Something we see on Westmont’s post-war ranches: the original framing is often better than people assume, but the foundation footings were never sized for a second floor. We design the load path properly, submit the engineering to LACBS in the county’s format, and match the new upper walls to the existing roofline so the addition looks like it was always there.
Trusted Brands We Service in Westmont
We work hands-on with established ADU and addition material brands like Abodu, Cover, and James Hardie. For Westmont homeowners, that means prefab options that cut on-site construction time and Hardie siding that holds up to the flat LA Basin heat without warping. We match the brand to your lot, budget, and county timeline. If you’re comparing a prefab Abodu kit against a stick-built addition, we’ll lay out the real cost difference, including what LACBS plan check will require for each. We keep local stock levels in mind so material delays don’t stretch your project out.
Common Home Addition Contractor Problems We See in Westmont Homes
- City-style plan sets sent to LACBS. Homeowners who’ve done projects in Inglewood or Gardena sometimes assume the submittal format is the same. It isn’t. A city-formatted package to a county office adds weeks to plan check because LACBS carries heavy volume across unincorporated LA County. We pre-format every submittal for the county.
- Assuming a 1950s wood-frame structure can carry new loads. Many Westmont ranches were built before current seismic codes. Adding a second story or a rear bump-out without checking the existing framing and footings is the fastest route to a plan-check rejection. We verify the structure first.
- Ignoring the Very High Fire Hazard Severity Zone overlay. Parts of Westmont fall under state fire-zone mapping. If your parcel is flagged, exterior material specs change, and that affects cost. We confirm parcel-by-parcel with LACBS before pricing, so you’re not surprised mid-project.
- Not accounting for HOA rules in newer developments. Westmont’s newer master-planned pockets have architectural review boards and HOA design standards. An addition that clears county plan check can still get bounced by the HOA if nobody pulled the approval first. We handle that paperwork early, not as an afterthought.
Pricing for Home Addition Contractor in Westmont, CA
Here’s what we tell Westmont homeowners on the first call:
- Ground-level room additions: $180 – $320 per square foot. A 300-square-foot addition runs $54,000 – $96,000.
- Second-story additions: $280 – $420 per square foot. A 500-square-foot upper floor runs $140,000 – $210,000.
- Bump-out additions: $200 – $300 per square foot, typically 100 – 250 square feet of added space.
- Garage conversions to living space: $140 – $220 per square foot in Westmont, where detached single-car garages are common on post-war lots.
What moves the number: foundation work, seismic detailing, fire-zone material requirements, and whether your HOA requires architectural review. We write the exact price down before any work starts, and we don’t change it at the door. Call (254) 602-5618 for a free written estimate.
We Also Serve Cities Near Westmont
Lodgewick ADU Builders serves homeowners across the South Bay and greater LA Basin. If you’re searching Home Addition Contractor in Westmont, you’ve found the right page, but we also take projects in Los Angeles, Long Beach, Anaheim, and Riverside, with the same written pricing, background-checked crews, and 365-Day Done Right Promise. Call (254) 602-5618 to confirm availability in your area.
Serving Westmont, CA - Our Local Coverage Area
We’re based in the Westmont 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 Westmont
No. Westmont is an unincorporated community, not an incorporated city, so there is no City of Westmont building counter. Every home-addition permit runs through LA County Building and Safety (LACBS) and the County of Los Angeles Department of Regional Planning. That means county fee schedules, county plan-check timelines, and county inspectors. We prepare county-formatted submittals so your project doesn’t stall at the first review. Call (254) 602-5618 and we’ll explain exactly what your parcel needs.
It can, if the existing foundation and wall framing are verified first and the engineering reflects current California seismic detailing. Many post-WWII Westmont ranches were never sized for second-story loads. We check the structure before design, submit the engineering in county format, and clear plan check without unnecessary re-submittals. Get a free structural assessment by calling (254) 602-5618.
Yes, if your parcel falls within a mapped zone. LA County’s fire-zone overlays trigger additional exterior material requirements, like ignition-resistant siding or specific eave detailing. That changes both design and cost. We confirm your parcel status with LACBS before pricing, so the written estimate reflects reality. Call (254) 602-5618 to check your parcel.
Because LACBS serves the entire unincorporated county, not just Westmont. The volume is far heavier than what a single-city counter in Gardena or Inglewood handles, so plan-check turnaround takes longer unless the submittal is complete and correctly formatted the first time. We front-load complete packages in the county’s exact format, which shaves weeks off approval. Call (254) 602-5618 to get your project moving through plan check now.
The things that affect how your addition ties in: roofline matching, exterior siding material, and window sizing. Builder-grade finishes like thin interior doors or basic vinyl windows are fine to keep in the existing structure, but the new addition should match the roofline and exterior so the home reads as one building. If you’re using James Hardie siding on the addition, matching the existing exterior matters. We walk through these decisions during the estimate. Call (254) 602-5618 for a free, written walkthrough.
Written by Russ Delmar, Owner at Lodgewick ADU Builders, serving Westmont since 2010.