ADU Company in Ontario, CA
Kitchen remodeling in Ontario usually means reworking a 1950s-to-1980s tract home kitchen that was built for a different era: closed off, low on counter space, and rarely set up for how Inland Empire families actually cook and gather now. At Westminster ADU Builders, we handle these remodels with the same discipline we bring to ADU construction, which means honest site assessments, written line-item pricing, and a plan that respects your home’s age and your lot’s quirks. Call (833) 620-3521 for a free estimate, and we’ll walk the space with you before you commit to anything.
Why Ontario Homes Are Different
Ontario’s housing stock is mostly single-story tract homes built between the 1950s and 1980s, and those houses share a set of conditions that change how a remodel or ADU project should be approached. The original kitchens are typically compact, framed with lumber that has settled, and wired for a time when a microwave was the heaviest appliance on the circuit. Add Ontario’s hot, dry summers and the Santa Ana wind season, and you get real design pressure: cooling loads matter, ventilation matters, and exterior finishes on any attached or detached addition need to handle serious sun exposure.
We also see a lot of lots where previous owners added on without permits. A converted garage, an enclosed patio, a room addition that never got final sign-off. When we plan an ADU or a kitchen expansion in the 91761 and 91764 zip codes, we frequently have to assess whether an existing structure can be legalized or whether it has to come out before new work starts. That’s exactly the kind of thing an out-of-area contractor misses, and it’s why we start every Ontario project by reading the lot, the easements, and the permit history before we draw a single line.
Our Main Ontario Services
Most Ontario homeowners call us for one of two reasons: they want an ADU on their lot, or they want to remodel a bathroom in the main house. Both jobs run into the same local realities, and we handle both from the same team.
ADU Builders in Ontario
Detached ADUs are the most common request we see in Ontario, especially in the older 91762 neighborhoods near downtown where rear alleys and utility easements shape what can actually be built. Our ADU Builders in Ontario page covers the full process, from figuring out whether your lot can take a detached unit to choosing between a prefab brand like Abodu or a custom site-built design. Prefab or custom-built: the right answer depends on your lot, your budget, and your timeline.
Bathroom Remodeling in Ontario
Bathrooms in Ontario’s mid-century tract homes run small, and the original tile work is often set on a mud bed that’s cracked or failing after 40 or 50 years. Our Bathroom Remodeling in Ontario service covers full tear-outs, layout changes, and finish work, whether you’re updating a hall bath or building out the bathroom inside a new ADU. One team, one contract, from the first demo swing to the final trim.
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.
Kitchen Remodeling in Ontario
Most Ontario kitchens we see were built in the 1950s through the 1980s, and they feel it: cramped layouts, worn cabinetry, insufficient outlets, and a ventilation setup that sends every bit of summer heat back into the room. Because summer cooling loads are already high in the Inland Empire, we pay close attention to range hood placement, window shading, and materials that won’t warp or fade under Ontario sun. Our Kitchen Remodeling service covers everything from a cabinet refresh to a full gut-and-rebuild, and we bring the same James Hardie exterior knowledge to any kitchen that opens to a new outdoor space or an ADU connection.
Cabinet Replacement
Signs you need it
Doors sag, drawer slides bind, and the boxes themselves start pulling away from the wall, especially in Ontario homes where decades of dry heat have taken a toll on particleboard and glue joints.
What it costs in Ontario
Cabinet replacement in Ontario typically lands between $12,000 and $28,000 depending on kitchen size, cabinet grade, and whether you’re changing the footprint or keeping the same layout.
How we do it
We measure the existing kitchen, help you select cabinet lines and finishes, remove the old boxes and hardware, and install the new cabinetry with shims and leveling so doors close cleanly.
Countertop Upgrade
Signs you need it
Laminate is peeling, tile grout is chipping out, or the surface is stained and heat-damaged beyond repair.
What it costs in Ontario
Countertop upgrades in Ontario generally run $3,500 to $8,000 for typical kitchen dimensions, with quartz and granite on the upper end of that range.
How we do it
We template the existing run, order the slabs, remove and dispose of the old tops, and set the new surface with proper seam placement and sink cutouts.
What Kitchen Remodeling Costs in Ontario
| Item | Typical range in Ontario |
|---|---|
| Cabinet replacement | $12,000 – $28,000 |
| Countertop upgrade | $3,500 – $8,000 |
| Full kitchen remodel | $25,000 – $65,000 |
What pushes a full kitchen remodel up in Ontario is electrical work: many of these older homes still have aluminum branch wiring or panels that can’t support a modern kitchen’s load, so upgrading the circuit run is often part of the job. We give you a written, line-item quote before we start, and the price doesn’t change once the work begins.
How long does a kitchen remodel take in Ontario?
Most kitchen remodels in Ontario take 4 to 8 weeks depending on scope, cabinet lead times, and whether we’re touching plumbing or electrical. Call (833) 620-3521 for a schedule estimate based on your specific project.
Will my Ontario kitchen remodel trigger a permit?
Any change to plumbing, electrical, or load-bearing walls requires a permit in Ontario, and we handle that paperwork as part of the job. Working without one can complicate a future sale or refinance.
Brands We Service in Ontario
Our Ontario projects include work with Abodu, Cover, and Dvele on the prefab side, and we maintain strong familiarity with Plant Prefab and Mighty Buildings for specific site conditions. For finish materials and exterior cladding, we lean on James Hardie fiber cement because it stands up to Ontario’s heat and fire season. Check our brands page for the full breakdown on what each system offers and where it fits best.
Pricing for ADU Company in Ontario, CA
| Service | Typical range in Ontario |
|---|---|
| Cabinet replacement | $12,000 – $28,000 |
| Countertop upgrade | $3,500 – $8,000 |
| Full kitchen remodel | $25,000 – $65,000 |
| Detached prefab ADU | $180,000 – $320,000 |
| Detached custom ADU | $225,000 – $450,000 |
| Garage conversion ADU | $90,000 – $180,000 |
| Attached ADU | $120,000 – $250,000 |
| Bathroom remodel (tub/shower) | $8,000 – $18,000 |
| Bathroom remodel (full) | $15,000 – $35,000 |
Prices in Ontario climb when we have to legalize or remove an existing unpermitted structure before new work can begin, and that’s common in the older 91762 and 91764 neighborhoods. Every estimate we give is a written line-item quote, so you’ll see exactly where your money goes before we order a single cabinet or pull a permit.
Neighborhoods We Serve in Ontario
We work across Ontario’s residential neighborhoods, from the downtown-era streets of the 91762 zip to the newer developments in 91764 and the 91761 corridor. Response time for an estimate visit is typically within a few business days anywhere in the city.
- Downtown Ontario (91762)
- Creekside (91761)
- Edenglen (91764)
- New Haven (91764)
- Park Place (91761)
Service Area – Cities Near Ontario
Beyond Ontario, our crews take projects in Montclair, CA, Upland, CA, Chino, CA, and San Antonio Heights, CA. If you’re on the edge of Ontario and not sure whether we cover your street, call us with your cross streets and we’ll tell you straight.
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 About ADU Company in Ontario
We typically schedule Ontario estimate visits within three to five business days, depending on the season and your neighborhood. Call (833) 620-3521 and we’ll give you the next available slot.
Yes. We prepare permit sets, file with the City of Ontario, and work through any HOA architectural review conditions where they apply. We’ve had Westminster ADU Builders projects in Ontario since 2016, so we know which HOAs in the 91761 and 91764 corridors are strict and which ones sign off quickly.
That’s one of the reasons homeowners bring us in. We can sequence the ADU construction and the main-house kitchen remodel so you’re not living through two separate job sites, and you’ll have one contract and one point of contact for both. Call (833) 620-3521 to talk through the timeline for your property.
What happens when you call
- 1A real person answersNo phone trees — talk to a local adu pro.
- 2You get an upfront price rangeHonest numbers before anyone is dispatched. No surprises.
- 3We come out and measureLicensed & insured, at a time that suits you — the visit and the quote are both free.
- 4You get the price in writingLine-itemed, yours to keep, and nothing starts until you say go.
What Ontario Customers Say
"Knew the local setback and parking rules cold, which saved us from designing something that would never have been approved."
— Daniel Norris"Sound insulation between the unit and the main house is better than I expected. You genuinely cannot hear the tenant."
— Farah Hassan"He gave us a realistic rental number for the finished unit rather than the optimistic one, and it's renting for about what he said."
— Erin Quinn