Fast, Reliable Bathroom Remodeling Across Ontario
Bathroom remodeling in Ontario, CA typically runs $18,000 – $42,000 for a full gut renovation, with tub-to-shower conversions landing between $9,000 and $16,000 depending on what’s behind the walls. We’ve worked in Ontario’s 1950s – 70s ranch tracts long enough to know that the real cost driver isn’t the tile you pick, it’s the wiring and plumbing hiding beneath it. Our crews are in Ontario weekly, from the older neighborhoods south of Holt Boulevard up through the newer subdivisions off Archibald Avenue. If you’re planning a remodel in Ontario, call us at (877) 265-9846 and we’ll walk the space with you before you spend a dollar.
Why Colonial ADU Builders Is Ontario’s Preferred Bathroom Remodeling Company
Ontario homeowners keep calling us back for one reason: we open walls the way a surgeon opens a patient, with a plan for what we’ll find. The city’s housing stock was built fast in the post-war boom, and that means cloth-wrapped wiring, galvanized supply lines, and cast-iron drains that have been quietly failing for 60 years. Most contractors in Ontario will quote you a pretty number and then act surprised when demolition reveals the truth. We don’t.
Our approach is built around the homes Ontario actually has. A 1962 ranch off East Euclid Avenue isn’t the same as a 1995 stucco box near Chino. We know the difference, we know what Ontario’s building department will require once walls are open, and we write every quote with realistic allowances for the upgrades those requirements trigger. Noel Carrasco, our owner, started this company because he got tired of watching Ontario homeowners get burned by change orders they never saw coming.
We’re not a bathroom franchise that parachutes into Ontario. We’re a local contractor with deep roots in the Inland Empire, and we’ve remodeled bathrooms in every corner of Ontario, from 91762 near downtown up through 91764 and 91798. When an Ontario building inspector walks your job, they know our work and our permit record. That matters when you’re dealing with the code triggers that older Ontario homes create.
Our Bathroom Remodeling Services in Ontario
Full Bathroom Remodel
A full bathroom remodel in Ontario means gutting everything: floors, walls, vanity, tub or shower, and all the plumbing and wiring behind them. In the ranch homes south of Holt Blvd, this is where we find the surprises that matter. Our process is inspection-first. We open the walls, we show you exactly what’s there, and we price the fix in writing before we continue. No mid-project stalls, no vague verbal promises. The finished bathroom meets current Ontario code, which means GFCI-protected circuits, proper ventilation, and waterproofing that will outlast the original construction by decades.
Shower and Tub Conversions
The most common project we do in Ontario is the tub-to-shower conversion. Homeowners in these mid-century homes are tired of stepping over a 14-inch tub wall, and a walk-in shower makes real sense. But converting a tub means exposing the plumbing stack and the framing around the valve. In 1950s and 1960s construction, that framing is often undersized by today’s standards and water-damaged from decades of slow leaks. We sister the studs, rebuild the valve wall to spec, and install a waterproof membrane system before tile ever goes up. Same for shower-to-tub conversions when young families in Ontario need a tub back.
Vanity and Fixture Upgrades
Sometimes the bones are fine and the bathroom just looks tired. We do plenty of vanity, countertop, and fixture upgrades in Ontario where the existing plumbing is solid and the homeowner wants a refresh rather than a gut job. But even a simple vanity swap in an older Ontario home can reveal shutoff valves that have seized, supply lines that are corroded, or drain traps that crack the moment you touch them. We price the visible work and carry a written allowance for the hidden work, so you approve any change in writing before we spend your money.
What happens when you call
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A real person answersNo phone trees — you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in Ontario
We install fixtures and finishes from manufacturers we trust in Ontario’s hard-water conditions. Mighty Buildings and Boxabl inform the way we think about efficient construction, but for bathrooms specifically, we lean on plumbing and waterproofing systems that hold up to the minerals in Ontario’s municipal water supply. We stock common replacement parts locally and can turn around most fixture swaps within days, not weeks. Our Bathroom Remodeling team carries the same brand-agnostic approach into every Ontario project: we recommend what fits your plumbing, your budget, and your water chemistry, not whatever is sitting in a warehouse.
Common Bathroom Remodeling Problems We See in Ontario Homes
- Cloth-wrapped or aluminum wiring. Homes built in Ontario between 1950 and 1972 often used cloth-insulated or aluminum branch circuits. Once a bathroom wall is open, Ontario code requires these circuits to be brought up to modern standards, which means a panel evaluation and often a dedicated GFCI circuit for the bathroom.
- Cast-iron and galvanized drain lines failing at the slab. Cast-iron drains corrode from the inside out, and pulling an old toilet in an Ontario ranch can crack a section of pipe that was already paper-thin. When that happens, you’re looking at sewer line replacement under the slab, and it’s never in the original quote unless your contractor planned for it.
- Undersized framing around tubs and shower valves. Builders in Ontario’s 1950s tracts used 2×3 studs in some bathroom walls and never imagined a homeowner would mount a heavy glass shower enclosure. We sister framing with new lumber and replace any stud that shows water damage before it compromises the tile work.
- Failed waterproofing behind original tile. The original tile showers in Ontario’s mid-century homes were often set over drywall or gypsum board with no waterproof membrane. By the time homeowners notice a crack in the grout, the framing behind it has been absorbing water for years. A proper remodel strips everything to the studs and starts fresh with a sealed waterproof system.
Pricing for Bathroom Remodeling in Ontario, CA
Here’s what we tell Ontario homeowners when they call us for a price. A full bathroom remodel in Ontario runs $18,000 – $42,000, and that’s an honest floor-to-ceiling number for a licensed contractor pulling permits. A tub-to-shower conversion runs $9,000 – $16,000. A vanity and fixture refresh starts around $4,000. The wild card in Ontario is the hidden condition allowance: we write 10 – 15% of the project value into the contract as an allowance for wiring, plumbing, or framing failures we can’t see until the walls are open. If we don’t spend it, you keep it. If we do spend it, you approve it in writing first. Call (877) 265-9846 and we’ll give you a free, written estimate built around your specific home and neighborhood.
We Also Serve Cities Near Ontario
Colonial ADU Builders is based in Apple Valley but our bathroom remodeling crews work throughout the western Inland Empire. Along with Bathroom Remodeling in Ontario, we regularly take on projects in Montclair, Upland, Chino, and San Antonio Heights. If you’re in one of those cities and dealing with the same mid-century construction issues we see in Ontario, call us. The same inspection-first, written-allowance process applies.
Serving Ontario, CA — Our Local Coverage Area
We’re based in the Ontario 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 – Bathroom Remodeling in Ontario
Because Ontario’s 1950s and 1960s ranch homes hide wiring and plumbing that cannot be evaluated until the walls are open, so a quote based on a visual inspection cannot capture the full scope. Cloth-wrapped wiring triggers a panel upgrade when the bathroom circuit is exposed. Cast-iron drains crack when the toilet is pulled. Galvanized supply lines are often so corroded internally that flow is barely functional. Our process in Ontario writes a 10 – 15% hidden-condition allowance into the original contract, so the cost doesn’t jump mid-project, it gets approved in writing before we touch it. Call (877) 265-9846 for an exact quote on your home.
Yes, any remodel in Ontario that moves plumbing, alters electrical, or changes the footprint requires a permit, and once the walls are open, the inspector will require the exposed systems to meet current code. That means GFCI protection, ventilation that exhausts outside, and water-resistant construction behind tile. We pull all permits for our Ontario jobs and we’ve built a working relationship with the city’s inspection office, so upgrades get planned ahead of time instead of treated as surprises.
We handle them with a process we built for exactly this scenario in Ontario’s older homes. Before demolition, we price a written allowance for hidden conditions. When we open a wall and find cloth wiring or a cracked cast-iron drain, we stop work, show you the issue, and give you a written change order with the exact cost to fix it. You approve before we continue. A 1962 ranch off East Euclid Avenue had a tub-to-shower conversion where we found cloth-wrapped wiring and galvanized pipes with 3/4-inch supply lines. We priced the panel upgrade and PEX repipe in writing before demolition continued, and the homeowner approved same day. No stall, no surprises inflated after the fact.
Often yes, but only a camera inspection of the line will tell you. In many Ontario homes south of Holt Blvd, the cast-iron drain is deteriorating but still functional; in others, it’s already collapsed and needs sectional or full replacement. We run a sewer camera on every Ontario remodel where we’re pulling a toilet or moving a drain. If the line is healthy, we leave it alone and document it. If it’s failing, we show you the footage and you decide. You’re not paying for a replacement you don’t need, and you’re not getting talked into one. Call (877) 265-9846 and we’ll schedule the inspection.
The biggest mistake is signing a contract with no written allowance for hidden conditions, then getting hit with a change order they had to accept under pressure. In Ontario’s mid-century housing stock, walls conceal 60-year-old wiring and plumbing that the original builders never intended to last this long. A contractor who quotes you a firm number without accounting for that is either naive about Ontario homes or planning to spring the cost on you later. Our contracts in Ontario include a transparent allowance line item, and every dollar of it is approved in writing before it gets spent.
Written by Noel Carrasco, Owner at Colonial ADU Builders, serving Ontario, CA and the surrounding Inland Empire with bathroom remodeling and full interior finish work.