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
Finding a General Contractor in Ontario who actually shows up, explains what’s behind the stucco, and prices the work honestly shouldn’t feel like a gamble. We work throughout Ontario’s 91762, 91764, and 91758 ZIP codes every week, and we know exactly what opening up a 1950s ranch or a 1970s two-story will turn up. Aluminum wiring. Thin clay sewer laterals. Framing that was fine in 1962 and undersized by today’s code. Our job is to find those problems before they find you, price them in writing, and keep your remodel moving. Call (866) 253-5808 and we’ll start with a walkthrough that looks for what other contractors skip.
Why Timberline Contractors Is Ontario’s Preferred General Contractor Company
Homeowners in Ontario call us because we don’t flinch when a wall comes down and the house turns out to be wired with aluminum branch circuits. That’s not a surprise to us. It’s the second remodel we’ve seen that month. Nelson Fung has built Timberline Contractors around the idea that a general contractor’s real value is knowing what’s behind the drywall before the drywall comes off, and having the brand partnerships and trade relationships to fix it under one contract.
Our Ontario customers stay with us because we write allowances into the scope of work for exactly the conditions this city’s housing stock produces. When a 91762 ranch opens up and shows original wiring or a hairline crack running through the slab, we’ve already priced the repair band. You approve a signed change order. We proceed. No shouting matches, no job site abandonment. That’s how a general contractor should operate in Ontario, and it’s why our work here keeps coming through referrals from neighbors, not paid ads.
Styles & brands we work with
Residential General Contractor in Ontario
Residential General Contractor work in Ontario rarely starts with what the homeowner thinks it starts with. You want a kitchen remodel, a bath remodel, or a room addition. What you often have is a 1950s tract home in 91762 with original aluminum wiring, a stucco-over-plaster exterior with no sheathing, and a sewer lateral that’s been settling into the clay for sixty years. Our job is to sequence the remodel so the visible outcome, the Cambria countertop or the Grohe fixture in the new bath, doesn’t get eaten alive by the hidden conditions underneath it.
Inspection Before Demolition
We walk every Ontario home before we write the contract. We knuckle-test exterior walls to find where a mid-century addition left a gap in the sheathing. We open the electrical panel door and photograph what’s behind it. We run a camera down the sewer line when the remodel touches a bath or kitchen drain location. This is how a $14,000 kitchen remodel stays a $14,000 kitchen remodel instead of becoming a $22,000 electrical rewire nobody budgeted for.
Allowances Written Into the Scope
Every Ontario remodel contract we write includes line-item allowances for the conditions this city’s homes produce: outdated branch wiring, undersized framing headers, failed shower waterproofing, or a thin clay lateral under the slab. The allowance is not an open-ended blank check. It’s a price band with a defined trigger. When the condition is confirmed during demo, we present a signed change order before touching the work. You approve the dollar figure. Then we build.
Hire a General Contractor in Ontario
When you hire a General Contractor in Ontario, you’re hiring someone to manage the sequence of trades, the permit schedule, and the material quality across every phase of the job. You’re also hiring someone who knows that the same ZIP code, 91764, can contain a 1958 tract home with plaster walls and a brand-new tilt-up warehouse. That range of construction geography is rare in the Inland Empire, and it means the contractor you choose needs to be fluent in both residential code upgrades and commercial build-out standards.
One Contract, Every Phase
We write one contract that spans the entire project, from demolition to final inspection. That includes electrical, plumbing, tile, cabinetry, roofing, and any exterior envelope work the remodel exposes. You’re not calling a different sub for every surprise. You’re calling Nelson Fung’s team, and we’re managing the fix inside the same scope and the same draw schedule.
The Permit Is Not Red Tape
Ontario’s building department has seen enough work to know exactly what to look for. We treat the permit inspection as a third-party sign-off that protects you. When a remodel triggers a code upgrade, like AFCI breakers on the new kitchen circuits or shear-wall reinforcement on a room addition, we pull the permit, schedule the inspection, and make sure the work passes before we cover it up. That’s not bureaucracy. That’s a warranty on the workmanship you can’t see.
Trusted Brands We Service in Ontario
We bring our full brand roster to Ontario projects, not a limited catalog. Need a roof replaced on a 91758 two-story? We install GAF, CertainTeed, and Owens Corning systems and we’ll help you compare the warranties side by side. Remodeling a bath on Euclid Avenue? You’ll choose from Grohe plumbing fixtures with the water pressure and finish durability to match. Our Ontario customers get the same brand access as our Chinatown clients, and we stock parts locally so a warranty replacement or a finish change doesn’t stall your job for two weeks.
See the difference
Before
After
Before
After
Before
AfterCommon General Contractor Problems We See in Ontario Homes
- Aluminum branch wiring. Homes built in Ontario between roughly 1965 and 1973 were often wired with aluminum. We budget for a copper rewire when a kitchen or bath remodel opens those circuits, because insurance and code won’t let you bury that risk behind new drywall.
- Thin clay sewer laterals. The flat lot grading across postwar Ontario subdivisions means sewer runs were installed shallow and often in clay. We scope the line before we start; a cracked lateral replaced during a remodel costs a fraction of what it costs after the tile goes in.
- Stucco-over-plaster with no sheathing. Older Ontario exteriors are frequently stucco applied directly over plaster on wood framing. Cutting into that without a knuckle-test first means hitting conduit and plumbing you didn’t know existed.
- Failed shower waterproofing. We see 1950s and 60s baths where the original pan liner has failed and water is silently working its way into the subfloor. Our bath remodels use the Schluter system to rebuild the waterproofing envelope from the substrate up.
Pricing for General Contractor in Ontario, CA
What does it cost to hire a general contractor in Ontario? Here are the line-item ranges we quote across the city, from 91762 up through 91758:
| Project | Ontario Market Range |
|---|---|
| Kitchen Remodel | $14,000 – $45,000 |
| Bathroom Remodel | $9,000 – $28,000 |
| Home Addition | $45,000 – $130,000 |
These ranges reflect the conditions we actually find in Ontario homes, including the permit-triggered upgrades that smaller operators exclude from their initial number. A $9,000 bathroom remodel on a 1959 slab home that needs lateral work will land differently than the same remodel on a 2015 infill build. The point is we tell you the difference before you sign, in writing. Call (866) 253-5808 and we’ll give you a line-item quote you can compare against anyone else’s.
We Also Serve Cities Near Ontario
While this page is for homeowners in Ontario, our crews regularly work just across the city line in Montclair, Upland, Chino, and San Antonio Heights. The housing stock and construction conditions overlap, so the same allowances and inspection process apply. If you’re in one of those cities and need a general contractor who already knows the area, 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
Expect aluminum wiring, undersized framing, and possibly no sheathing behind the stucco. We write allowances for all three into your contract before demolition starts. When we opened a 1958 stucco-over-wood-frame ranch in 91762 for a kitchen remodel, our crew found original aluminum branch wiring and a thin clay sewer lateral under the slab. Both were already covered by the allowances, so we priced the copper rewire and lateral replacement as a signed change order before the drywall went back up. That kept the job on schedule and your budget predictable. Call (866) 253-5808 if your walls are still closed and you want them opened right.
We pull the permit, schedule the inspection, and include the upgrade in the contract as a priced line item or an allowance with a defined trigger. Ontario’s building department will require AFCI protection on new circuits, shear-wall reinforcement on additions, and often upgraded grounding when we touch the panel. None of that should surprise you. If it appears in the field, it’s already in the scope or it’s priced as a signed change order before we proceed. Call (866) 253-5808 for a remodels quote that includes the code work other contractors leave out.
Allowances are the difference between a remodel that finishes and a remodel that stalls in a dispute. In Ontario, where the same street can have original 1950s construction and 1990s additions, what’s behind the wall is not uniform. We write allowance bands for wiring, laterals, framing, and waterproofing. When the hidden condition is confirmed, you get a signed change order with a fixed price before we touch it. That’s how we keep the draw schedule moving and your approval on record. Call (866) 253-5808 if you want a contract that actually describes what we’ll find.
Yes. Ontario is one of the few Inland Empire cities where the same ZIP code can contain a 1960s tract home and a new tilt-up warehouse. Our crews are fluent in both residential code upgrades and industrial build-out standards. That dual fluency means your residential remodel benefits from the same scheduling discipline and material management we bring to commercial work, without the overhead cost of a firm that only does warehouses. Call (866) 253-5808 and tell us what you’re building.
The draw schedule is tied to completed milestones, not days on site. We structure it so you pay for work that has been inspected and approved, not work that’s been promised. When a surprise arises during demolition, like aluminum wiring in a 1965 ranch, we present a signed change order with a fixed price. That change order gets its own draw line tied to its own completion milestone. You never pay ahead for a fix that hasn’t been built or inspected. Call (866) 253-5808 and we’ll walk you through the draw schedule on your specific project.
Written by Nelson Fung, Owner at Timberline Contractors, serving Ontario and the Inland Empire.