







A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateFast, Reliable Home Addition Contractor Across Fremont
Adding a room or expanding your footprint in Fremont usually starts with a question about cost, timeline, or whether your 1960s ranch can even support the work. Those are fair questions, and you should get a straight answer before any walls come down. A room addition or bump-out in Fremont typically runs $180 – $320 per square foot depending on whether we’re working over a slab, a crawlspace, or doing a second-story lift. The bigger issue many Fremont homeowners face isn’t the construction itself, it’s finding a contractor who will write down a price, show up, and stand behind the work a year later. Russ Delmar and the team at Lodgewick ADU San Jose do exactly that, and we do it under The Kingswell Guarantee: written price first, defined arrival window, clean job site, and a written guarantee on every project. Call (669) 266-4319 and we’ll talk through your lot, your plans, and a real number.
Why Lodgewick ADU San Jose Is Fremont’s Preferred Home Addition Contractor Company

Fremont homeowners have been burned enough times to be skeptical of contractors who promise everything and put nothing in writing. That skepticism is healthy. We’re part of the Kingswell family of home-service companies, established in 2010, and every project we take on in Fremont operates under the same rules: a written price before work starts, a defined arrival window, a clean job site, and a written guarantee delivered before a single nail is driven. No price changes at the door. No “we’ll figure out the scope later.” That’s The Kingswell Way.
Our crews know Fremont’s housing stock intimately. We regularly work in neighborhoods like Ardenwood, Niles, and Northgate where ranch homes from the 1950s through 1970s dominate. That matters because the condition of an original slab foundation or a 60-amp electrical panel changes how an addition gets designed and permitted. We handle the utility upgrades, seismic bracing, and foundation work that older Fremont homes almost always need, so you’re not juggling three subcontractors who don’t talk to each other. And when you call us at (669) 266-4319, a live person answers. No voicemail loop. Day or night.
Second Story Addition Contractor in Fremont
A second story addition contractor in Fremont has to solve a problem most homeowners don’t see coming: your existing single-story home was never engineered to carry a second floor. We see it in Centerville and Glenmoor regularly. The ranch homes built between 1950 and 1980 in Fremont rest on slab or crawlspace foundations with framing that meets mid-century code, not today’s seismic standards. Before we frame anything upward, we evaluate the existing foundation, confirm lateral load paths, and design the structural upgrade the addition requires. On most Fremont lots, a second story addition runs $280 – $400 per square foot because of the shoring, stairwell surgery, and seismic retrofitting involved. You also get written pricing before we start, so that number doesn’t move once framing begins.
Foundation and Seismic Work Tied In
Fremont sits near the Hayward Fault, which means any vertical addition triggers a structural review and a real plan, not a shrug. We spec and install the shear walls, hold-downs, and foundation anchors the plans call for. The permit gets pulled, the inspection gets passed, and it’s all in the written scope.
Living Through a Second Story Build
Going up means your roof comes off for a stretch. We sequence the work so your family can stay in the home as long as practical, and we give you a real schedule with a defined arrival window before we start. You’ll know which weeks are loud, which are dusty, and when the roof gets closed back in.
Garage Addition Contractors in Fremont

Garage addition contractors in Fremont do two very different jobs under one label: extending the garage footprint for more car or workshop space, and converting part of an existing garage into living area. Both are common here. Fremont’s ranch and split-level homes often sit on flat, rectangular lots that leave room to push a garage outward by 10 to 18 feet. Most Fremont garage additions run $27,000 – $55,000 for a single-bay extension with framing, roofing, siding, and a new slab tie-in. But the real wildcard in Fremont is the original electrical panel. Many garages still carry 60-amp service from the 1960s, which cannot support a finished space with modern outlets and lighting. We almost always include a service upgrade to 200 amps when the addition becomes a conditioned space.
When the Garage Becomes a Room
If the goal is a den, office, or bedroom rather than vehicle storage, the job reads more like a garage conversion with structural work. Our Garage Conversion Contractor in Fremont handles those projects from slab to drywall, including the insulation and moisture management Fremont’s wet winters demand. You won’t get condensation on the new walls if the vapor barrier and ventilation are done right the first time.
Detached Garage Additions for ADU Potential
Some Fremont homeowners build a detached garage addition with an eye toward a future accessory dwelling unit above or beside it. If that’s your thinking, we’re the team to talk to. As ADU Builders in Fremont, we plan the foundation depth, plumbing stubs, and electrical capacity so the garage addition is ADU-ready from day one. That saves you from tearing out new concrete two years later.
Common Home Addition Contractor Problems We See in Fremont Homes
- Undersized original electrical panels. Fremont homes built before 1980 frequently still run 60-amp service, and no inspector will sign off on a finished addition fed by that panel. We include the 200-amp service upgrade in the written price rather than surprising you with it mid-project.
- Slab foundations with no seismic ties. Older Fremont slabs were poured before current seismic codes, so additions over or adjacent to them need doweling, anchor bolts, and shear reinforcement. This is standard on our Fremont work, not an upcharge discovered at framing.
- Moisture intrusion during wet winters. Fremont’s rainy season runs November through March, and an addition that isn’t flashed and sealed correctly will show mold or water stains within the first year. We flash every roof-to-wall junction and window opening as if it will be tested by ten years of El Niño storms.
- Contractors who vanish after the final check. The most common complaint we hear from Fremont homeowners isn’t about construction quality, it’s about silence. That’s why the 365-Day Done Right Promise is written into every project: if the work isn’t right, we come back and make it right. Free.
Trusted Brands We Service in Fremont
When your addition involves prefabricated components or specific material systems, we’re hands-on with the brands Fremont homeowners ask about most. We work with James Hardie siding and trim, which holds paint and resists moisture far better than raw wood in Fremont’s winter wet cycles. For detached additions and ADU-ready structures, we install and finish Tuff Shed shells, and we have working familiarity with Abodu and Cover prefab ADU systems, including Abodu repair in Fremont, for homeowners who want factory-built precision on a faster timeline. Because we order from local Bay Area suppliers, Fremont customers don’t wait on long lead times for basic framing packages or siding materials. We keep the common items on hand.
Pricing for Home Addition Contractor in Fremont, CA
Here’s what you can expect in Fremont right now. A straightforward room addition on a slab foundation runs $180 – $260 per square foot. Bump-out additions, where we extend an exterior wall to gain 4 to 10 feet of floor space in a kitchen or bath, typically land between $45,000 and $90,000 depending on plumbing and cabinetry. Second story additions start around $280 per square foot and go up with complexity. Garage additions, as noted, run $27,000 – $55,000 for a single bay. These are real, written ranges based on Fremont’s permit fees, material costs, and typical lot conditions, not national averages. Your lot, your foundation, and your finish choices move the final number. The estimate is free, it’s in writing, and it won’t change at the door. Call (669) 266-4319 to schedule yours.
We Also Serve Cities Near Fremont
Our crews work primarily in Fremont, but we regularly take on addition projects in the surrounding Bay Area communities. Homeowners in Fremont often send us to family in Union City, Milpitas, Palo Alto, and San Jose. If you’re anywhere in that radius and need a straight answer on an addition, give us a call at (669) 266-4319. We’ll let you know if your area is within our regular service range, and if not, we’ll point you to someone who can help.
Serving Fremont, CA - Our Local Coverage Area
We’re based in the Fremont 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 Fremont
We typically get someone to a Fremont home for a free estimate within 2 to 3 business days, and many same-week requests from central Fremont neighborhoods like Ardenwood or Niles are easy to accommodate. Call (669) 266-4319 and we’ll lock in a specific day and a two-hour arrival window, not a vague “sometime between 8 and 5.”
Yes. We work throughout Fremont, including Ardenwood, Niles, Centerville, Northgate, Glenmoor, Warm Springs, and Mission San Jose. The crew familiar with your part of town will be the one who walks your lot and measures your foundation.
No. Under The Kingswell Guarantee, the written price you approve before work begins is the price you pay. If we uncover a condition during demolition that the plans didn’t account for, we stop, we show you what we found, and we put the change in writing before we proceed. No surprise invoices at the end of the job. Call (669) 266-4319 for a written estimate.
Fremont’s permit fees for additions tend to run higher than Milpitas and Union City, largely because of the city’s thorough plan review process and the seismic requirements tied to the Hayward Fault. You should budget $8,000 – $20,000 for permit and plan-review fees on a typical addition, depending on scope. We handle the permitting, the plans, and the inspections as part of the project.
Every Lodgewick ADU San Jose project in Fremont includes the 365-Day Done Right Promise in writing. If work we performed fails within a year of completion, we return at no charge and make it right. That covers construction defects in our workmanship, site-built structures, and installed materials. It’s a written guarantee, not a handshake. Call (669) 266-4319 and we’ll show you the exact language before you sign anything.
Room Additions, Second Stories, and Bump-Outs: Our Full Scope in Fremont

Beyond second story and garage work, our Home Addition Contractor team handles room additions, sunroom additions, and bathroom additions across Fremont. Sunrooms are popular here because Fremont’s climate stays mild enough to use a well-built sunroom most of the year, while bathroom additions often run into the same undersized electrical panels and aging plumbing the rest of the house has. Bump-out additions, where we extend an exterior wall to gain floor space without a full foundation pour, are one of the most cost-effective ways to make a Fremont kitchen or bedroom feel twice as large. Whatever the scope, you get the same written price, the same defined arrival window, and the same written guarantee on every project. That’s The Kingswell Way, and it’s what Fremont homeowners deserve. Call (669) 266-4319 to schedule your free estimate.
Written by Russ Delmar, Owner at Lodgewick ADU San Jose, serving Fremont with written prices and written guarantees on every home addition.









