ADU Company in Ontario — One Fixed Price, Permits Handled

We handle the design, the engineering, and the city permit, then build it. One contract, one crew, one accountable point of contact. Free feasibility check on your lot before you commit.

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ADU Company in Ontario, CA

Kitchen remodeling in Ontario usually means reworking a 1950s-1970s stucco ranch where the original galley kitchen still has its first cabinets, a 60-amp panel feeding it, and no ventilation to speak of during Inland Empire summers. Fullerton ADU Builders has served Ontario since 2017, and we approach every kitchen job with the same lot-level thinking we bring to ADU work: what’s the existing footprint, what’s the panel situation, and how does the new kitchen need to perform when it’s 104 degrees outside and three generations are cooking at once. Call (877) 801-4497 to talk through your project.

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Why Ontario Homes Are Different

Ontario’s housing stock was built fast during the post-war boom, and it shows in the kitchens. Homes in the tracts off Euclid Avenue and around the 91762 ZIP are mostly single-story stucco ranches from the 1950s through the 1970s, with original layouts that treated the kitchen as a closed-off utility room, not a gathering space. The electrical panels are often 60 to 100 amps, which means any kitchen remodel that adds an induction range, a second oven, or dedicated circuits for a microwave and dishwasher usually triggers a panel upgrade first. That’s a regular part of our Ontario kitchen jobs, not an add-on surprise.

The climate drives material choices here. Ontario gets real heat, regularly over 100 degrees in July and August, and Santa Ana winds push dust and dry air through the city in fall. That means cabinet finishes and flooring need to handle big temperature swings and low humidity, and we spec ventilation that actually moves air out of the house instead of recirculating it. Flat and low-slope roofs over kitchen additions or bump-outs take direct sun all summer, so we detail flashing and insulation to prevent the heat from bleeding down into the kitchen. These are not generic California concerns; they’re Ontario-specific realities.

Multigenerational living shapes kitchen demand in Ontario more than any design trend. Large households in 91761 and 91762 regularly cook for six or more people daily, which changes the math on storage, countertop run, and appliance sizing. A kitchen that works for a retired couple in Fullerton can feel undersized for the three-generation households we work with here. Our remodeling recommendations start from who actually cooks in the house and how many meals a week get made, not from a showroom layout.

Our Main Ontario Services

Ontario homeowners call us most often about two projects: adding an ADU to a lot that’s tighter than it looks, and updating a bathroom in the same vintage housing stock that makes kitchens feel dated. Each gets its own dedicated page here.

ADU Builders in Ontario

Ontario’s ADU market leans toward multigenerational housing: detached casitas for parents or adult children on lots where a 1950s ranch already occupies much of the buildable area. That makes setback math, lot-coverage checks, and utility upgrades the real work here, not luxury guest suites. We work with seven prefab manufacturers across a range of price points and timelines, and we also handle site-built ADUs where the lot or the homeowner’s goals call for it. See ADU Builders in Ontario for the full breakdown.

ADU Builders in Ontario

Bathroom Remodeling in Ontario

Older Ontario homes often have one full bathroom for three or more residents, and the original cast-iron plumbing and 60-amp panels make a simple refresh more involved than it looks. We handle full bathroom remodels, including aging sewer laterals and venting corrections that are routine in this housing stock. Because we bundle bathroom work with ADU construction, homeowners can address the primary residence and the new unit under one contractor relationship. Details are on our Bathroom Remodeling in Ontario page.

Bathroom Remodeling in Ontario
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What happens when you call

  1. 1
    A real person answersNo phone trees — you reach a local pro.
  2. 2
    You get an upfront price rangeHonest numbers before anyone is dispatched.
  3. 3
    A background-checked tech heads outLicensed & insured, dispatched right away.
  4. 4
    You approve before work beginsNothing starts until you say go.

Kitchen Remodeling in Ontario

Kitchen remodeling in Ontario is a different job than it is in a newer coastal city. We’re typically opening up a closed-off galley in a 1950s-1970s ranch, upgrading a 60-to-100-amp panel to handle modern appliances, and designing around daily multigenerational cooking in the Inland Empire heat. That’s the pattern in 91761, 91762, and 91764, and it shapes every recommendation we make. If you’re comparing options or just want a straight answer on cost, our Kitchen Remodeling hub walks through the full scope of what we do.

Full Kitchen Renovation

Signs you need it

The layout hasn’t changed since the house was built, cabinet doors no longer close square, and the kitchen can’t support more than one cook at a time.

What it costs in Ontario

A full kitchen renovation in Ontario typically runs $27,000 to $50,000, depending on cabinetry, countertop material, and how much structural or electrical work the 60-100-amp panels require.

How we do it

We start with a site visit to measure the existing footprint and confirm panel capacity, then produce a fixed-price line-item quote, handle permits, and sequence demo, rough-in, and finishes around your household’s schedule.

Cabinet Refacing and Replacement

Signs you need it

The cabinet boxes are solid but doors are delaminating or the layout is fundamentally too small for the number of people cooking daily.

What it costs in Ontario

Cabinet refacing or replacement in Ontario typically ranges $8,000 to $18,000, with replacement running higher when we’re reconfiguring a galley layout into something workable for multigenerational households.

How we do it

We’ll assess whether the existing boxes are worth refacing or whether a layout change makes more sense, then quote both paths so you can compare the cost against the functional gain.

Countertop and Backsplash Upgrade

Signs you need it

Laminate or tile counters from the original build are chipped, stained, or too low for comfortable prep, and the backsplash is failing at the seams.

What it costs in Ontario

Countertop and backsplash replacement in Ontario usually ranges $4,000 to $9,000, heavily dependent on slab selection and linear footage.

How we do it

We template after cabinets are set, install with a focus on heat and moisture resistance that matters in Ontario’s hot dry summers, and seal everything before final walkthrough.

What Kitchen Remodeling Costs in Ontario

Item Typical range in Ontario
Countertop and backsplash upgrade $4,000 – $9,000
Cabinet refacing or replacement $8,000 – $18,000
Full kitchen renovation $27,000 – $50,000

How long does a kitchen remodel take in Ontario?

A full kitchen remodel in Ontario usually takes 6 to 10 weeks, with cabinet refacing or countertop-only work running 1 to 3 weeks. Permitting with the City of Ontario adds time up front, which we fold into the schedule before demo starts. Call (877) 801-4497 for a timeline specific to your project.

Will I need a panel upgrade for my Ontario kitchen remodel?

Many Ontario homes we work in still have 60 to 100 amp panels, so adding an induction range, wall oven, or dedicated microwave circuit often requires an upgrade. We check panel capacity during the estimate so the cost is in your quote, not a change order later.

Brands We Service in Ontario

We work across the prefab spectrum, and that includes servicing units from manufacturers like Abodu, Cover, and Tuff Shed. James Hardie fiber cement cladding is our standard exterior spec for durability in Ontario’s heat and wind conditions. See our brands for a full breakdown of what we’re authorized to work on.

Pricing for ADU Company in Ontario, CA

Service Typical range in Ontario
Countertop and backsplash upgrade $4,000 – $9,000
Cabinet refacing or replacement $8,000 – $18,000
Full kitchen renovation $27,000 – $50,000

What pushes pricing up in Ontario is the age of the housing stock: 60-100-amp panel upgrades, aging sewer laterals, and rear-setback corrections on shallow lots all show up as line items that newer cities don’t face. That’s why we quote fixed, written, line-by-line pricing before any work starts, so the number you approve is the number you pay.

Neighborhoods We Serve in Ontario

We work across the full Ontario footprint, including the older tracts where ADU and kitchen decisions are driven by lot shape and panel capacity. Our typical response time for an estimate in the Ontario area is 1 to 2 business days.

  • Downtown Ontario
  • North Ontario
  • South Ontario
  • West Ontario / 91762 detached-garage tracts
  • Archibald Ranch

Service Area – Cities Near Ontario

Fullerton ADU Builders serves Ontario and the surrounding Inland Empire communities. If you’re in Montclair, CA, Upland, CA, Chino, CA, or San Antonio Heights, CA, we can bring the same lot-specific approach to your project. Each city has its own permitting quirks and housing stock, and we’re familiar with all of them.

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

Ready to get started? Free estimates · Written quotes before work starts response in Ontario
Call (877) 801-4497

What happens when you call

  1. 1
    A real person answersNo phone trees — talk to a local adu pro.
  2. 2
    You get an upfront price rangeHonest numbers before anyone is dispatched. No surprises.
  3. 3
    We come out and measureLicensed & insured, at a time that suits you — the visit and the quote are both free.
  4. 4
    You get the price in writingLine-itemed, yours to keep, and nothing starts until you say go.

What Ontario Customers Say

★★★★★ 4.8 from 4+ reviews

"Garage conversion to a one bedroom unit. He handled the plans, the city submittal, and every round of corrections. Took six months from first meeting to final inspection and he never once made the permit process my problem."

— Tim Padgett

"The kitchenette layout he suggested made better use of the space than the one on our original sketch."

— Marisol Guzman

"Unit came out great and the tenant is happy. The timeline ran long, largely because of how slow the city was on plan check, though a couple of the delays were scheduling on their end."

— Greg Reed

How It Works in Ontario

Getting your adu handled is simple and fast.

1

Call or Request a Free Estimate

Tell us about your adu needs and we provide an upfront, transparent quote — no obligation, no hidden fees.

2

Licensed Technician Dispatched

A background-checked, certified technician arrives in Ontario — typically within 30–60 minutes, with parts stocked on the truck.

3

Problem Solved, Guaranteed

We complete the job to your full satisfaction, backed by our warranty and 100% satisfaction guarantee.

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