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
Hiring a General Contractor in Ontario means finding someone who understands what your specific lot actually requires, not just what the plan set shows. We serve every corner of this city, from the 1950s ranch tracts south of the 60 to the acreage parcels pushing east toward the 91761 corridor. You reach us directly at (833) 756-5936, and you’ll talk to someone who has walked Ontario job sites, not a call center. If you’re pricing a room addition, a detached shop, an ADU, or a full gut remodel, we quote it from the actual conditions on your property. That’s the only honest way to do it here.
Why Iron Beam Contractors Is Ontario’s Preferred General Contractor Company
Ontario homeowners keep calling us back because we scope the job the way it actually builds. Nolan Driscoll runs our estimating and field teams with a simple rule: no bid goes out until we’ve confirmed whether your parcel falls under Ontario city permitting or San Bernardino County review. That single check changes the cost of a detached shop or ADU more than any countertop selection ever will. We’ve built our local reputation on catching those things before the pad is staked, not after.
Our Ontario customers also know we don’t broker work out to a rotating cast of strangers. One accountable team handles your interior remodel, your roof, your hardscape, and your prefab unit under one agreement. When something needs a decision at the rough inspection, you call one number: (833) 756-5936. That’s the difference between a general contractor and a coordinator.
We’ve pulled permits across the 91762, 91764, and 91758 ZIP codes, and we know which inspectors and which plan-check comments are coming before they arrive. That local fluency means fewer resubmissions, fewer stalled weeks, and a draw schedule that doesn’t surprise you.
Styles & brands we work with
General Contractor Services in Ontario
General Contractor Services in Ontario cover the full build from demolition to final walkthrough. When you’re adding square footage on an Ontario lot, the price is driven by foundation type, soil condition, and whether the addition triggers septic or grading review. A home addition in Ontario typically runs $45,000 to $130,000. A garage conversion lands between $30,000 and $80,000 depending on whether you’re bringing the slab up to habitable standard and running new power from the house.
Detached Shops and Outbuildings
On Ontario’s eastern acreage, a detached shop is rarely a simple slab. You’re dealing with county setbacks from existing septic and well lines, equipment staging across open ground, and SCAQMD dust control on any grading day. We scope the rough-ins before the first cut, because adding power or plumbing after the slab is poured costs double.
We recently scoped a detached shop and gravel approach on an open lot off the 91761 corridor, where SCAQMD dust rules forced us to water the access road and stage equipment in phases rather than a single long cut and fill. The bid was built around a rough-in for power and septic before any slab went down, then locked down in writing after a December wind event pushed the grading schedule.
Room Additions and ADUs
Adding living space in Ontario means working around how the original house was built. Most of the older stock is single-story stucco on slab, and tying a new addition into that slab takes a specific approach so you don’t inherit a step-down where the rooflines meet. ADU construction in Ontario runs $90,000 to $220,000, and that range widens further on acreage where the county requires its own setback review before the unit’s footprint is approved.
Driveway and Approach Work
A concrete driveway on an Ontario lot runs $4,500 to $12,000. On the eastern acreage parcels, you’re often looking at a long gravel approach before the concrete even starts, and that approach is part of the scope, not an afterthought. We price the haul, the subgrade, and the dust-control measures that SCAQMD will enforce on any grading day.
What happens when you call
- 1
A real person answersNo phone trees — you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Construction Company in Ontario
A Construction Company in Ontario has to build for two very different realities. In the established tracts around the 91762 and 91764 ZIP codes, you’re usually working on a 1950s to 1970s ranch where the original supply lines and slab matter more than the finish schedule. Near the airport and warehouse belt, you’re building or modifying structures under SCAQMD rules that don’t apply the same way a few miles north in the foothills. We know the difference because we’ve built in both.
Tract Home Renovations
The classic Ontario ranch is simple in shape but unforgiving when you start moving walls. Original galvanized supply lines and shallow slab-on-grade construction mean we plan for replacement plumbing and a structural check before any framing goes up. That’s not scope creep. That’s the real condition of the building.
Acreage Builds and Site Work
Out on the open lots, construction cost follows the dirt more than the design. A pad that sits fine on paper might need fill, compaction, or a retaining edge once we check the grade. On acreage parcels at Ontario’s eastern edge, grading and septic/well setbacks are reviewed through San Bernardino County rather than the city, so a shop or detached ADU’s footprint, not its finishes, usually drives what the job really costs. We confirm which authority reviews your parcel before we quote, because that answer changes the number.
Trusted Brands We Service in Ontario
We don’t stock generic materials and hope they work. We specify what the project needs and what will hold up in Ontario’s summer heat and Santa Ana wind cycles. For fencing on acreage and residential lots alike, we work with Jerith aluminum systems and ActiveYards options that won’t require repainting every few years. For hardscape and paver approaches, Belgard materials give us the color and joint consistency that the Inland Empire’s clay-heavy soil demands when it shifts through wet and dry seasons. We keep local supply relationships in the Inland Valley, so materials don’t sit in a yard in Los Angeles while your schedule slips. When Nolan Driscoll reserves a material package for an Ontario job, it’s reserved against your address.
See the difference
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After
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After
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AfterCommon General Contractor Problems We See in Ontario Homes
- Slab movement in the older ranch tracts. The 1950s and 1960s homes in Ontario’s core neighborhoods sit on shallow slabs, and decades of hot, dry summers with occasional heavy rain cycles have shifted more than a few interior door frames. We check for slab cracks and settling before we quote an addition, because tying new concrete to a moving slab guarantees failure.
- Galvanized supply lines at the end of their life. In the original citrus-grove tracts, the supply plumbing is often original galvanized steel, which corrodes from the inside and kills water pressure. Any bathroom or kitchen remodel in these homes should plan for a repipe or at minimum a supply line replacement back to the main.
- SCAQMD dust and idling rules on grading days. Near the airport and the warehouse belt, any earthmoving triggers South Coast Air Quality Management District dust-control requirements. If your contractor doesn’t build water trucks and phased equipment staging into the bid, you’ll see a change order the moment the inspector shows up.
- County permitting surprises on the eastern edge. Ontario’s eastern parcels often fall under San Bernardino County review for septic, well, and grading. We’ve seen homeowners get a city permit for a detached structure only to find out the county wants a full setback review on the same footprint. That’s a five-figure oversight if it’s caught late.
Pricing for General Contractor in Ontario, CA
Here’s what Ontario homeowners should expect on the major scopes:
| Project | Ontario Price Range |
|---|---|
| Home Addition | $45,000 – $130,000 |
| ADU Construction | $90,000 – $220,000 |
| Garage Conversion | $30,000 – $80,000 |
| Concrete Driveway Installation | $4,500 – $12,000 |
On acreage, three things move the number: the haul distance for materials and equipment, the amount of grading and fill required, and whether the county hits you with a septic or well setback that forces the structure into a smaller footprint. In the older tracts, the big variables are the slab condition and the state of the original supply lines. We put every one of these items in writing before we start, so the number you sign is the number you build to. Call (833) 756-5936 for a free, line-item estimate on your Ontario property.
We Also Serve Cities Near Ontario
Our crews work across the Inland Valley every week. If you’re in Montclair, Upland, Chino, or San Antonio Heights, you get the same direct access to Nolan Driscoll and the same scoping discipline we bring to every Ontario job. The permit office and the soil changes by city, but the way we quote doesn’t. Call (833) 756-5936 from anywhere in the valley and we’ll schedule the site walk.
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
We start by checking the supply lines and the slab before we touch the existing tile or vanity. In these ranches, the original galvanized supply is usually corroded, so a vanity or shower install often includes replacing the supply stub-outs back to the main. The slab condition matters too, because a shower pan on a cracked or settling slab will fail at the mortar bed. We quote the install with those two checks built in, and the number we give you is the number you pay. Call (833) 756-5936 and we’ll walk your specific bathroom before we quote it.
We’re in Ontario multiple days a week, and we can typically get a site walk scheduled within a few business days depending on the size of the project. Permitting is the real timeline driver in Ontario, especially if your parcel falls under county review on the east side. We’ll tell you the honest schedule when we see the property.
Yes. We work the 91762, 91764, 91758, and 91798 ZIP codes regularly, from the ranch tracts near the 60 to the acreage and industrial edges off the 91761 corridor. The permitting authority and the soil change depending on where you are, and we adjust our scope accordingly.
Our labor rates are the same across the Inland Valley, but the project cost changes because Ontario has specific conditions. SCAQMD dust rules apply in ways they don’t in the higher foothill towns, and the county permitting on the east side adds review time and sometimes engineering that a Chino or Upland lot might not face. That’s the honest difference.
We stand behind every project with a written workmanship warranty, and we’re still answering our phone years after the final walkthrough. Nolan Driscoll keeps all warranty records by address, so if something fails on an Ontario job, the fix gets scheduled without a records hunt. Call (833) 756-5936 and we’ll walk you through what the warranty covers before you sign.
Written by Nolan Driscoll, Owner at Iron Beam Contractors, serving Ontario and the Inland Valley with licensed general contracting and full-scope remodeling.