Fast, Reliable Bathroom Remodeling Across Ontario
Bathroom remodeling in Ontario, CA typically runs $18,000 – $42,000 for a full hall bath and $28,000 – $65,000 for a primary bathroom, depending on what’s hiding behind the walls. We’re the team Ontario homeowners call when they want a real contractor who opens up a 1950s bathroom and knows exactly what they’ll find. Our crew knows the ZIP codes, the housing stock, and the panel upgrade conversations that older Ontario homes force. Call (866) 730-4828 to schedule a free estimate, and we’ll walk your bathroom with you before any number goes on paper.
Why Bungalow ADU Builders Is Ontario’s Preferred Bathroom Remodeling Company
We specialize in Bathroom Remodeling and ADU construction, which means our estimators and project managers see Ontario’s older housing stock every single week. The homes off Euclid Avenue, the tree-lined blocks near Chaffey High, the post-war tract pockets south of the 10 – we’ve torn out bathrooms in all of them. Homeowners in Ontario call us because we don’t flinch when demo reveals cloth-wrapped wiring or a rusted galvanized drain line. We’ve priced that work before. We know what it costs because we’ve done it dozens of times in 91762 and 91764.
Nate Calloway leads our team, and he’s built a reputation in the Inland Empire for quoting bathrooms honestly. Not low to win the job, then change-ordering the real cost later. Ontario homeowners who’ve worked with us tell their neighbors the same thing: the number we give is the number we stand behind, unless hidden conditions force a written change, and then we show photos and a fixed price before we touch anything.
Our Bathroom Remodeling Services in Ontario
Full Bathroom Remodeling
A full bathroom remodel in Ontario usually means gutting to the studs, which is where our process protects you. Most mid-century homes in 91761 and 91762 still have the original framing layout, cast-iron or galvanized supply lines, and a single 15-amp circuit running the whole bathroom. We open the walls, document everything, and if the bones need upgrading, we price it and get your written approval before ordering a single fixture. The result is a bathroom that meets current code – GFCI circuits, proper venting, waterproofing – not just new tile over old problems.

Tub-to-Shower Conversion
Tub-to-shower conversions are the most common request we field in Ontario’s older central-core neighborhoods. Homeowners in 91762 and 91764 want a walk-in shower for aging parents or just daily convenience, but the original tub alcove is often framed with undersized 2x4s that won’t carry modern waterproof board the way they should. We reframe the alcove when needed, install a proper shower pan with a waterproofing membrane, and tie in a new exhaust fan to reduce the humidity that Ontario’s hard water and heat can leave lingering. A tub-to-shower conversion in Ontario typically runs $12,000 – $22,000 depending on what the demo exposes.

Waterproofing and Tile
Waterproofing is where cheap bathroom remodels fail in Ontario, and we treat it as structural work, not cosmetic. Decades of Santa Ana heat cycling crack mortar beds and grout lines in older Ontario homes, and by the time tile looks bad, the framing behind it has usually been wicking moisture for years. We use modern waterproofing membrane systems under every shower floor and up every wet wall, then lay tile that handles the Inland Empire’s temperature swings. If your original 4×4 ceramic is starting to pop loose or the grout won’t stay sealed, that’s a sign the substrate is moving or holding water.

Fixture and Finish Upgrades
For bathrooms that don’t need a full gut, we handle targeted upgrades: new vanities, toilets, exhaust fans, lighting, and hardware. These jobs are smaller in scope but still benefit from an Ontario-specific eye – older homes often lack a dedicated GFCI outlet at the vanity, and the original exhaust fan may vent into the attic rather than outside. We correct those issues as part of a finish upgrade so you’re not paying for a cosmetic refresh that leaves code violations and moisture problems intact. Expect $5,000 – $12,000 for a solid finish-level upgrade.

What happens when you call
- 1
A real person answersNo phone trees — you reach a local pro.
- 2
You get an upfront price rangeHonest numbers before anyone is dispatched.
- 3
A background-checked tech heads outLicensed & insured, dispatched right away.
- 4
You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in Ontario
We build ADUs and remodel interiors using product systems we trust, and that includes fixtures and finishes from manufacturers engineered for the Inland Empire’s conditions. Our work frequently includes James Hardie fiber-cement on ADU exteriors, and when a bathroom is part of a prefab unit from Abodu or Cover, we tie the bathroom waterproofing and venting into the unit’s existing shell. For Ontario homeowners adding a detached ADU with a full bath, those brands give us a head start on the framing and exterior, and we handle the interior trades – plumbing fixtures, shower pans, tile, exhaust – under one scope of work.
Common Bathroom Remodeling Problems We See in Ontario Homes
- Cloth-wrapped or aluminum branch wiring. Ontario’s 1950s tract homes run on wiring that was never designed for modern bathroom loads. When we open a wall and find it, the panel and circuit evaluation becomes a written change order, not a verbal surprise.
- Failed shower pans and hidden framing rot. Original tile over a cracked mortar bed has been leaking into the subfloor for years. The visible damage is cosmetic; the framing rot behind it is structural and only shows after tear-out.
- Undersized 100-amp panels. A new bathroom exhaust fan, GFCI protection, and a heated floor can push an old Ontario panel past its capacity. The permit process often triggers a service upgrade, and generic quotes don’t include it.
- Galvanized supply lines at the end of their life. Rusted galvanized pipes restrict flow and eventually leak. When a bathroom is already open for remodel, it’s the cheapest time to replace the supply runs back to the main.
Pricing for Bathroom Remodeling in Ontario, CA
Here’s what Ontario homeowners should actually budget for in 2026. A full hall bath remodel runs $18,000 – $42,000. A primary bathroom with a larger footprint, double vanity, and walk-in shower runs $28,000 – $65,000. A tub-to-shower conversion sits at $12,000 – $22,000. Finish-level updates – new vanity, toilet, fan, lights, hardware – run $5,000 – $12,000. The biggest swing factor in Ontario’s older homes is what demo exposes: if the original wiring, drain lines, or framing need replacement, that adds $3,000 – $8,000 to the scope. We write allowances into our contracts for exactly those conditions, and any change is priced and approved in writing before work continues. Call (866) 730-4828 for a free estimate on your Ontario bathroom – the walkthrough doesn’t cost a thing and you’ll get a real line-item number.
We Also Serve Cities Near Ontario
Our crews work across the Inland Empire corridor, including Montclair, Upland, Chino, and San Antonio Heights. If you’re just outside Ontario and evaluating a bathroom remodel alongside an ADU addition, we’d be glad to walk your property. For the full scope of what we do across the region, see Bathroom Remodeling in Ontario and give us a call at (866) 730-4828.
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 demo exposes what was hidden: cloth-wrapped wiring, rusted galvanized drains, undersized framing, or failed waterproofing – all common in Ontario’s 1950s tract homes. We write allowances into every contract for these conditions and price any change order with photos and a fixed number before work continues. Call (866) 730-4828 for an exact quote on your specific bathroom.
Not always, but often enough that we evaluate the panel on every older Ontario home before we quote. If the existing 100-amp panel can’t carry a new GFCI circuit, exhaust fan, and any heated floor, the permit will trigger a service upgrade. We’ll tell you during the walkthrough whether that’s likely, so the quote reflects reality.
We tear out to the studs on every full remodel, inspect the framing, and document what we find. If the framing is rotted or the subfloor is compromised, we write a change order with a fixed price and get your written approval before replacing anything. No work continues on a damaged substrate without that sign-off. Call (866) 730-4828 if you suspect water damage behind your bathroom tile.
Current code requires GFCI-protected outlets, a properly vented exhaust fan that terminates outside, minimum framing sizes for the shower enclosure, and waterproofing that meets modern standards. Older Ontario homes often fail all four, and the permit process enforces them. We build those upgrades into the scope so the finished bathroom passes inspection cleanly.
Yes, and this is exactly where our ADU and bathroom remodeling overlap. We handle the bathroom inside an existing or new detached ADU as a single scope, including waterproofing, exhaust, tile, and any subpanel work the unit needs. If the ADU bathroom wasn’t originally permitted or the waterproofing is failing, we’ll evaluate it the same way we do a main-house bathroom, with the same written change-order process.
Contact Bungalow ADU Builders for Bathroom Remodeling in Ontario
If you own a home in Ontario’s older core – north of the 10, in 91762 or 91764, or anywhere the original 1950s bones are still doing the work – you need a contractor who’s opened those walls before. We know what’s back there, and we price it so the number you approve is the number you pay. Call (866) 730-4828 to schedule a free walkthrough and estimate. We’ll walk your bathroom, check the panel, look at the framing, and give you a real line-item quote – not a brochure number.
Written by Nate Calloway, Owner at Bungalow ADU Builders, serving Ontario since day one.