Kitchen remodeling
Bathroom remodeling
Home additions & ADU
Roofing
Windows & doors
Driveway & pavers
FenceFree written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
Fast, Reliable General Contractor Across Ontario
A general contractor in Ontario, CA should understand that this city runs two construction worlds at once. Tilt-up warehouse shells rise along the I-10 and Route 60 corridors while 1950s stucco tract homes in 91762 and 91764 wait for someone who knows how to retrofit their raised foundations and aging utility laterals. That’s the work we do. Alder Contractors handles whole-home remodels, additions, ADUs, and exterior replacements across Ontario, including the neighborhoods off Euclid Avenue, Holt Boulevard, and Archibald Avenue. We carry the full general contracting license, we pull permits when the scope of work requires them, and we write the scope documents that keep change orders from blindsiding you after demolition opens up a wall. Call (833) 467-7020 for a free estimate, or read on to see what actual pricing in Ontario looks like.
Why Alder Contractors Is Ontario’s Preferred General Contractor Company
Ontario homeowners tell us the same thing in nearly every consultation: they are tired of juggling three bids, two material suppliers, and a tile installer who never returns calls. That is exactly why our General Contractor team operates under a single contract with a single point of accountability. When we remodel a kitchen in 91764, the cabinetry, countertops, plumbing fixtures, and the framing behind them all move on one schedule, not four separate ones.
Our work across Ontario has put us inside more mid-century stucco homes than we can count, and those houses share the same bones. Built fast after the post-war boom, they carry narrow lots, older galvanized supply lines, and raised foundations with laterals that were never meant to handle an ADU’s added load. Knowing that before we write a bid is the difference between an honest number and a change-order nightmare. We walk the property, check the foundation, inspect the existing electrical panel and plumbing supply, and only then do we quote the job. Homeowners in 91761, 91762, 91764, and 91798 get that same process every time.
Nelson Ibarra leads every Ontario project with one rule: the bid we hand you is the bid we intend to build to. No vague allowances that quietly drain the budget. No sub-trade runaround. When something hidden shows up after demolition, we document it, show you the photos, and walk you through the exact change before we touch another stud. That discipline comes from years of tilting walls back open on Ontario’s older housing stock and knowing what actually hides behind the stucco.
Styles & brands we work with
Construction Company in Ontario
A construction company in Ontario has to hold two standards at once: the tolerance required for slab-on-grade commercial work and the patient, retrofit mindset required for 1950s-70s tract housing. Alder Contractors sits squarely in that split. We manage additions, garage conversions, structural work, and whole-home remodels under one general contracting license, which means you are not stitching together a foundation contractor, a framing crew, and a plumber from three different phone numbers.
Older Tract Retrofits and Structural Work
Most of Ontario’s residential core north of the 60 Freeway and south of I-10 was built between 1950 and 1975. Those homes are wood-frame, stucco-clad, often on raised foundations, and they are hitting the age where galvanized pipes fail at the threaded joints. Retrofits here are different from new construction in the newer subdivisions to the south and east. We expect sagging subfloors, undersized foundation sill plates, and original electrical panels that cannot handle a modern kitchen’s load. A home addition in Ontario runs $45,000 to $130,000 depending on square footage, foundation conditions, and whether the roof structure needs reinforcing.
Garage Conversions and ADUs
A garage conversion in Ontario runs $30,000 to $80,000, and an ADU construction project runs $90,000 to $220,000. Those numbers reflect permit fees, structural upgrades, utility work, and the inspections Ontario’s building department requires before walls close. We have converted detached garages off Archibald Avenue and interior garages in 91762. The biggest variable is always the slab: some older garages were poured with no vapor barrier and no rebar, which means a new floor assembly before a single wall goes up.
Remodeling Contractor in Ontario
A remodeling contractor in Ontario working on 1950s-era homes is doing a different job than one working on 1990s tract builds. Older homes hide cast-iron drain lines, undersized joists, and framing that drifted out of square decades ago. Alder Contractors approaches every Ontario remodel expecting those conditions and quoting accordingly, which is why our numbers hold while other bids quietly double.
Kitchen and Bath Scope in Ontario’s Older Homes
A kitchen remodel in Ontario ranges $14,000 to $45,000. The spread is real and it is mostly about what is behind the walls. A basic cabinet and countertop refresh in a 1990s subdivision home sits at the lower end. A gut remodel in a 1950s tract house off Holt Boulevard, where the subfloor is rotten under the sink and the electrical panel needs upgrading, sits at the top. Bathroom remodels run $9,000 to $28,000 for the same reason. We specify Cambria or Caesarstone countertops, Kohler or Moen fixtures, and KraftMaid cabinetry when the budget supports it, and we never spec materials that cannot handle Ontario’s hard water and dry heat.
Exterior Replacements That Endure Inland Empire Weather
Roof replacement in Ontario runs $8,000 to $20,000, and window replacement runs $4,500 to $15,000. The Inland Empire sun does not age a roof the way the coast does. It bakes it. Santa Ana winds drive dust into every gap, and the UV load on south-facing elevations is relentless. We install GAF and CertainTeed roofing systems with upgraded underlayment, and for windows we lean on PGT and ECO Window Systems for impact-rated or high-UV-resistant frames. These choices cost a bit more on the front end. They cost a lot less over a decade.
Trusted Brands We Service in Ontario
We stock and install materials from more than 50 vetted brands, which means Ontario homeowners are not stuck with whatever the local supply house happened to have on the shelf. For exterior work, we regularly specify PGT windows and doors, Tamko roofing, and CertainTeed products. For hardscape, Belgard and Techo-Bloc pavers hold up under the Inland Empire sun far better than big-box alternatives. Outside Ontario, the temptation is to grab whatever is cheapest at the lumberyard. We do not build that way. Fast turnaround for Ontario jobs comes from having material relationships already in place, not from cutting corners on what gets installed.
See the difference
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After
Before
After
Before
AfterCommon General Contractor Problems We See in Ontario Homes
- Galvanized water lines corroding at the threads. We see this in nearly every 1950s-60s home we open up in 91761 and 91762. The pipe looks fine from the outside and falls apart the moment a wrench touches it.
- Raised foundations with undersized girders. Ontario’s older tract homes were built fast and light. Adding an ADU or a second-story addition without evaluating the foundation first is how you get cracked stucco and a failed inspection.
- Stucco failures on south and east elevations. The Inland Empire sun and Santa Ana wind-driven dust age stucco faster here than in coastal LA. Hairline cracks become water paths, and water paths become mold inside the wall cavity.
- Skipped permits on load-bearing work. We find this all the time: a previous owner removed a wall without a permit, and now the ceiling is sagging two inches. Permits are not red tape on structural work. They are the record that protects you when you sell the house.
Pricing for General Contractor in Ontario, CA
Here are the line-item ranges we quote most often for work in Ontario. These reflect current local market conditions, including permit fees, material costs, and the labor reality of working on older tract housing.
| Project Type | Typical Ontario Range |
|---|---|
| Kitchen Remodel | $14,000 – $45,000 |
| Bathroom Remodel | $9,000 – $28,000 |
| Home Addition | $45,000 – $130,000 |
| ADU Construction | $90,000 – $220,000 |
| Garage Conversion | $30,000 – $80,000 |
| Roof Replacement | $8,000 – $20,000 |
| Window Replacement | $4,500 – $15,000 |
What moves a number inside these ranges? Structural discoveries after demolition, permit and inspection requirements, utility relocation, and material tier. A kitchen with Cambria counters and Kohler fixtures costs more than one with builder-grade alternatives. A bathroom that requires moving a drain line costs more than one where the fixtures stay put. We write these variables into the bid up front, so you see the numbers before you sign. Call (833) 467-7020 for a free, line-item estimate on your specific Ontario property.
We Also Serve Cities Near Ontario
Beyond Ontario, our crews work throughout the surrounding Inland Empire. We serve Ontario plus Montclair, Upland, Chino, and San Antonio Heights, which means our material suppliers and permitting contacts are already established across the local area. If you live just outside Ontario but want the same whole-home contractor, call us.
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 General Contractor in Ontario
Because Ontario’s housing stock is older and the climate is harsher on materials. A 1950s tract home in 91762 typically needs subfloor repair, electrical panel upgrades, and galvanized pipe replacement before cabinets go in, and those are costs a coastal bidder may not carry. Inland Empire UV and Santa Ana dust also mean exterior and window specs have to be upgraded. The cheaper bid often does not include the material spec that will survive here. Call (833) 467-7020 and we will show you a line-item breakdown for your specific house, not a generic kitchen price.
Yes, and it matters more here than most homeowners realize. Ontario’s building department requires permits for structural, electrical, plumbing, and mechanical work on ADUs and garage conversions, and the inspections that follow are what protect you when you sell. We have seen unpermitted conversions block title transfers years later. Alder Contractors pulls permits, schedules inspections, and keeps a written record of every sign-off. That record is your insurance policy.
At minimum, you want a detailed scope of work, a written material allowance schedule (brand and model named, not just “mid-grade tile”), a payment schedule tied to visible milestones, and a change order policy spelled out in writing. You should also ask for proof of general contractor licensing and insurance. We provide all of those documents before any contract is signed. If a contractor in Ontario won’t put the scope in writing, walk away.
Standard galvanized fasteners, untreated fence posts, and unsealed paver joints fail fastest here. The Inland Empire sun accelerates rust on cheap hardware, and Santa Ana wind drives dust into every unsealed joint until it becomes a weed bed or a water path. We specify hot-dip galvanized or stainless fasteners, pressure-treated or steel-reinforced fence posts (Master Halco materials when the budget allows), and sealed paver joints using polymer sand. The incremental cost is real, but so is the decade of service life you gain.
It means the labor and material market is stretched, and some contractors quote residential work using commercial assumptions that do not translate. Tilt-up warehouse work is slab-on-grade, fast, and repetitive. Retrofitting a 1950s stucco home requires different skills: shoring load-bearing walls, rerouting old utilities, and working in tight lot conditions off Euclid Avenue where a concrete truck has nowhere to park. A general contractor in Ontario who only bids commercial will under-price the residential and make it up in change orders. We price the residential correctly the first time because that is where we actually work.
Call (833) 467-7020 to schedule your free estimate with Alder Contractors. We serve Ontario, Montclair, Upland, Chino, and San Antonio Heights from our base in Rialto, and we can walk your property within the week. You will get a written scope of work, named material allowances, and real numbers, not a handshake.
Written by Nelson Ibarra, Owner at Alder Contractors, serving Ontario and the Inland Empire.