Fast, Reliable Home Addition Contractor Across Fontana
Adding square footage to a Fontana home usually means one thing: your lot already has room, but your house doesn’t. We get that. Our crews work in Fontana every week, from the 1940s ranch tracts west of Sierra Avenue to the newer subdivisions around Sierra Lakes. When you call, a live person answers – not a voicemail. That’s how Lodgewick ADU Builders has run every project since 2010, and it’s how we run yours. If you’re weighing a garage addition, a bump-out, or a full bathroom addition, call (254) 602-5618 and we’ll walk the property with you, then put a written price in your hands before any work starts.
Why Lodgewick ADU Builders Is Fontana’s Preferred Home Addition Contractor Company
Fontana homeowners tend to ask the same two questions: will the price hold, and will you come back if something fails? Both are fair. Our answer is The Kingswell Guarantee, and it’s in writing on every project. A written price before work begins. A defined arrival window. A clean job site. A written 365-Day Done Right Promise: if the work isn’t right, we come back and make it right, free of charge, within the guarantee period.
Russ Delmar leads our local teams, and he grew up in the same trade culture that built these Fontana neighborhoods. He knows a 1950s ranch on a 12,000 sq ft lot behaves differently than a 1990s tract home in a gated Sierra Lakes community. That local knowledge is why our Fontana customers tend to recommend us to neighbors and cousins. We don’t leave a site until the crew has swept it, and we don’t consider a job done until the homeowner walks it with us and signs off.
Our Home Addition Contractor team coordinates scheduling from the Inland Empire office, which means response time to most Fontana neighborhoods is same-week for estimates. For a city this hot, that matters. You don’t want to sit on a quote for three weeks while the attic hits 120 degrees.
Garage Addition Contractors in Fontana
Garage Addition Contractors in Fontana work on a housing stock that’s unusually well-suited to this kind of project, and for a specific reason. Central and western Fontana neighborhoods were built between the 1940s and 1960s for Kaiser Steel workers, and those lots routinely run 8,000 to 14,000+ sq ft. That means the garage often sits with usable space beside it or above it, and the lot itself gives you room to expand without eating the whole backyard. A two-car garage addition in Fontana typically runs $55,000 to $110,000 depending on finish level, whether the existing slab can be reused, and what the inspector says about the current structure.
Attached Garage Additions
When the garage already shares a wall with the house, the addition often means extending into the side yard and converting part of the old garage into living space. This is where Fontana’s older stock bites back: many of these garages were built with undersized footings and no vapor barrier. We account for that in the initial inspection, not after the concrete is poured.
Detached Garage Additions with Living Space
On the big central-Fontana lots, a detached garage addition frequently becomes a hybrid project: garage below, in-law space above. That triggers ADU requirements under California code, which in this city nearly always starts with a service panel upgrade. More on that below.
Bathroom Addition Contractor in Fontana
A Bathroom Addition Contractor in Fontana has to plan for what’s behind the wall, not just the tile in front of it. Homes built in the 1950s and 1960s here carry original plumbing – galvanized supply lines, cast-iron waste stacks – that often fails during inspection. A full bathroom addition, including plumbing rough-in, waterproofing, and finishes, typically runs $35,000 to $65,000 in Fontana. Smaller half-baths come in lower, around $22,000 to $35,000. Those ranges assume the existing subfloor can support the wet area; if it can’t, the price moves.
Primary Suite Bath Additions
When a Fontana homeowner adds a primary bath, the project usually means pulling a permit, moving or adding a sewer tie-in, and bringing ventilation up to code. That last part is not optional: a bathroom with no proper exhaust in Climate Zone 10 grows mold inside a year. We spec a properly sized exhaust fan and a dedicated circuit as standard, not as an upgrade.
Second Bathroom for Multigenerational Households
Fontana has one of the largest multigenerational Latino/Hispanic populations in the Inland Empire. A lot of the bathroom additions we build are for abuelos moving in, adult children returning, or a shared bath that finally gets split. These projects prioritize a curbless shower, blocking in the walls for grab bars, and a door wide enough for a wheelchair. We build those in from the framing stage.
Trusted Brands We Service in Fontana
We have hands-on experience with the prefab and panelized systems that work well on Fontana lots: Cover, Boxabl, and Mighty Buildings. Each one fits a different situation – some for fast backyard units, some for second-story additions, some for homes near the foothills where fire code changes the assembly. If you’re considering a prefab addition, we’ll help you compare what actually works on your parcel, with real numbers for your specific lot, not a brochure range. For Fontana customers, that means a faster path from permit to closed walls.
Common Home Addition Contractor Problems We See in Fontana Homes
- The 100-amp panel surprise. Open a wall in a 1940s-1960s Fontana ranch and you’ll often find a 100-amp panel feeding cloth-wrapped wiring with no ground. Adding a bath or garage addition then triggers a service upgrade, a sub-panel, and an EV-ready circuit. If that’s not written into the contract, it’s the single biggest driver of mid-job change orders in this city. We write it in as a line-item allowance from day one.
- Foothills fire-zone requirements. Parcels along Baseline and Cherry fall in a CAL FIRE Very High Fire Hazard Severity Zone. A permit there triggers ember-resistant vents, Class A roofing, and one-hour exterior assemblies. That’s $15,000 to $25,000 before the first stud goes up, and contractors who don’t flag it at the first site visit blow their own bids.
- Undersized HVAC for Climate Zone 10. Fontana summers hit 108°F to 112°F in the heat-trapping basin. If the mini-split or ducted system is spec’d with coastal-caliber insulation minimums, the new addition never cools properly. We spec Title 24 compliance for a hot inland climate zone every time, not as an upsell.
- Failed waterproofing on flat additions. Older Fontana homes often have low-slope or poorly flashed roof transitions. A new addition that ties into that roofline without addressing drainage will leak within two winters. We inspect the existing roof-to-wall connection before we design the addition.
Pricing for Home Addition Contractor in Fontana, CA
Here are straight numbers for the Fontana market. A garage addition runs roughly $55,000 to $110,000. A bathroom addition runs $35,000 to $65,000. A bump-out addition of 150 to 300 sq ft typically runs $45,000 to $90,000. A second-story addition over an existing footprint starts around $150,000 and goes up from there. What moves the number in Fontana specifically: the age of the existing panel, whether the parcel is in a Very High Fire Hazard Severity Zone, and the condition of the original foundation. Our estimates are free, and the written price you get is the price you pay – change orders only happen if you approve them in writing first.
Key Takeaways
- A garage addition in Fontana runs roughly $55,000 – $110,000.
- A bathroom addition in Fontana runs roughly $35,000 – $65,000.
- 100-amp panels on older Fontana homes often force a service upgrade and sub-panel before permits pass.
- Foothills parcels near Baseline and Cherry trigger fire-hardening costs of $15,000 – $25,000.
- Every Lodgewick project includes a written 365-Day Done Right Promise in the contract.
We Also Serve Cities Near Fontana
Our crews cover Fontana and the surrounding Inland Empire communities: Bloomington, Rialto, Rancho Cucamonga, and Riverside. If you’re in one of those cities and searching for a Home Addition Contractor in Fontana, we can usually get to you the same week for an estimate. The same written price, the same guarantee, the same crew standards apply.
Serving Fontana, CA - Our Local Coverage Area
We’re based in the Fontana 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 Fontana
Yes, in nearly every case. A 100-amp panel on a 1950s Fontana home typically cannot support the added load of a new bathroom or garage addition, especially once the inspector requires a dedicated sub-panel and an EV-ready outlet under current California code. We write the service upgrade and sub-panel into the contract as a line-item allowance from the start, so you see the number before the wall opens, not after. Call (254) 602-5618 and we’ll confirm what your panel can actually carry.
Your addition will trigger ignition-resistant construction requirements: ember-resistant vents, Class A roofing, and one-hour exterior wall assemblies. That adds $15,000 to $25,000 to the project before framing begins. We check the parcel’s VHFHSZ status at the first site visit and include those costs in the written estimate, so the bid doesn’t move mid-project.
Fontana sits in a heat-trapping basin that routinely hits 108°F to 112°F in summer. Insulation values and HVAC sizing calibrated for coastal climates leave a Fontana addition chronically under-conditioned. We spec each addition for Climate Zone 10 and Title 24 inland compliance, with a properly sized mini-split or ducted system matched to the actual room load. It’s not an upsell; it’s the difference between a room you use and a room you avoid from June through September.
We stop work and tell you. Then we price the fix as a change order the same day, and you approve it in writing before we touch another stud. This happens regularly in Fontana’s older homes, where a bathroom addition often exposes rotted sill plates, failed flashing, or framing that doesn’t meet current span tables. Because we build inspection and allowance language into the original contract, the surprise doesn’t become a runaway cost. On one 1950s ranch off Citrus Avenue, we opened a wall for a bathroom addition and found cloth-wrapped wiring with no grounding; we pulled a service upgrade, added a sub-panel and EV-ready circuit, and replaced the exposed runs to pass inspection. The owner saw the price before we framed the first wall.
Usually yes, but the HOA’s CC&Rs may restrict exterior changes, rooflines, or construction hours, and those restrictions sit on top of city permits. We review the CC&Rs before we pull a permit so the addition doesn’t violate a covenant that costs you money later. Call (254) 602-5618 for a free estimate and we’ll check what your HOA actually allows.
If you’re ready to get a real number for your addition, call (254) 602-5618. We’ll set a time that works, walk the property with you, and put the price in writing – every job, every time. That’s The Kingswell Way.
Written by Russ Delmar, Owner at Lodgewick ADU Builders, serving Fontana and the surrounding Inland Empire.