Free in-home measure and quote - PGT, CGI and CWS impact lines compared on your actual openings, style by style
Fast, Reliable Window Replacement Across Ontario
Window replacement in Ontario is a decision shaped more by this valley’s wind and clay soil than by style trends. Our work in Ontario starts with a straight answer on your glass package, your frame type, and your schedule. TruePane has been replacing and upgrading windows in Ontario homes since Dale Kessler set the standard that still governs every job. If you live along the Euclid Avenue corridor, in the 91758 zip, or anywhere nearby, call (888) 635-0804 for a free estimate with line-item pricing before any order is placed.
Why TruePane Windows & Doors Is Ontario’s Preferred Window Replacement Company
We’ve worked on enough 1950s and 1960s stucco tract homes in Ontario to know the pattern before we knock. The aluminum sliders are oxidized, the glaze is failing, and the original flashing was never built for a 60 mph Santa Ana event out of the Cajon Pass. Ontario homeowners keep our number because a live person answers every call, 24/7, and because our crews are local. Not a regional dispatch center. Not a subcontractor you’ll never see again.
The Done Right Promise matters here. So does The Keystone Standard: both manufacturer warranty layers registered in writing, durations stated, before the truck leaves the driveway. Dale’s rule still hangs on the whiteboard: if the pane is not true, the job is not done. Ontario customers get that in writing on every quote.
Key Takeaways for Ontario Homeowners
- Expect $500-$1,200 per opening for insert replacement in Ontario, and $900-$2,400 per opening for full frame work.
- Low-SHGC glass is not optional here. Climate Zone 10 makes it the single biggest determinant of cooling cost.
- Santa Ana wind loads crack more than seals. They rack frames over shifting clay soil, especially east of Euclid.
- TruePane quotes in writing, free, and holds that number. No change orders after the order is placed.
Our Window Replacement Services in Ontario
Full Frame Replacement
Full frame replacement means removing the entire existing window, frame and all, down to the rough opening. In Ontario, we do this most often on original aluminum sliders from the late 1940s through the 1970s. The old frames have racked from decades of expansive clay soil shifting under the slab, and a new sash in an old frame would only inherit the problem. We reset the opening square, flash the perimeter to code, and install the new unit properly. Window Replacement of this scope typically runs $900-$2,400 per opening in Ontario, depending on size and glazing.

Insert Window Replacement
An insert, or pocket replacement, fits a new window into the existing frame. It’s the right choice when the original frame is still square and the surrounding stucco and interior trim are worth preserving. Ontario homes built in the 1980s and later often fall into this category. Expect $500-$1,200 per opening. We measure every opening twice, because an eighth of an inch is the difference between a clean install and a callback.

Storm Window Replacement
Older Ontario homes with original wood sash windows sometimes rely on exterior storm windows as the first line of defense against wind-driven rain. When those aluminum storm frames get bent or their glazing cracks, the interior window is exposed. We replace storm units and can match the profile on Craftsman and Spanish Revival homes along the Euclid Avenue corridor where non-standard openings are common. Storm window replacement in Ontario typically costs $200-$500 per unit.

Energy-Efficient Upgrade
This is the work we recommend most in Ontario, because this city logs some of the highest cooling degree days in the LA Basin. Air conditioning runs from April into October. Upgrading to dual-pane low-E glass with argon fill and a low Solar Heat Gain Coefficient changes the actual temperature in a west-facing bedroom. Energy-efficient window upgrades in Ontario run $700-$1,800 per opening, and the payoff is immediate in summer.

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.
Trusted Brands We Service in Ontario
We’re an authorized installer for more than a dozen manufacturer lines, and for Ontario homes we regularly quote, PGT, and CGI side by side on paper. When a homeowner wants impact-rated PGT or CGI glass for wind protection near the Cajon Pass corridor, we show them the exact SHGC and U-factor numbers. We also stock replacement sashes and hardware for Ply Gem and CWS lines, which keeps turnaround tight for repair work across Ontario.
Common Window Replacement Problems We See in Ontario Homes
- Wind-driven rain past failed sealant. Santa Ana events out of the Cajon Pass drive water sideways into original single-pane aluminum frames. The result is stained drywall around the sash and rot in the rough opening.
- Racked frames from expansive clay soil. The valley floor’s clay expands and contracts seasonally. On 1960s slab foundations, this racks window jambs until the sash binds and the meeting rail cracks.
- Failed seals on 1990s insulated glass. Homes built in the early 1990s got dual-pane windows, but the seals are now at the end of their life. Fogged argon cavities are a chronic call across Ontario.
- High solar gain overheating rooms. Original single-pane windows in Climate Zone 10 turn a closed room into an oven by 2 p.m. in August. The cooling bill tells the story.
Pricing for Window Replacement in Ontario, CA
A typical window replacement in Ontario runs $500-$2,400 per opening. Insert replacement lands on the lower end, $500-$1,200. Full frame replacement with new flashing and a reset opening runs $900-$2,400. Storm window units are $200-$500. Energy-efficient dual-pane low-E upgrades generally fall between $700 and $1,800 per window, depending on size and the manufacturer line you choose. The variables are glazing, frame material, opening size, and whether we’re working on a 1963 tract home or a 1920s Craftsman with non-standard rough openings. What doesn’t change is the quote. We price in writing, free, and hold that number. Call (888) 635-0804 for a free estimate.
How Ontario’s Winds and Clay Soil Change the Window Decision
Ontario’s Santa Ana winds, funneled through the Cajon Pass, can hit 50-60 mph and drive wind-driven rain into aging window assemblies. That racks lightweight aluminum frames and blows out weatherstripping at a rate rarely seen ten miles south. It’s a problem no generic window page addresses, because no generic window page has worked on a 1963 stucco tract home in the Euclid Avenue corridor. On one job, we replaced a bank of original aluminum sliders with ViewLux casement windows. The 50-year-old jamb on the south wall had racked from expansive clay soil, so we reset the rough opening, installed dual-pane low-E glass with argon fill, and flashed the perimeter before a Santa Ana event hit two days later. Zero air leakage. That’s the standard in Ontario.
The second local factor is the soil. Contractors who work Ontario’s older east-side neighborhoods near the airport know the valley floor’s expansive clay causes 1960s and 1970s slab foundations to shift seasonally. Door frames rack so that doors bind in summer and gap in winter. Sticky door service calls are nearly as routine here as full window replacements. A window replacement that doesn’t account for the rough opening’s squareness will bind inside a year. We check every opening with a level before we quote.
We Also Serve Cities Near Ontario
TruePane’s crew covers Ontario and the surrounding Inland Empire communities, including Montclair, Claremont, Upland, and Rancho Cucamonga. If you’re in any of these nearby cities, the same team, the same written quote, and the same Done Right Promise apply. Call (888) 635-0804 and ask for a free estimate.
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 - Window Replacement in Ontario
Look for water staining on interior drywall below the sash corners, and for daylight visible through the frame seams. On a windy day, run a damp hand along the window perimeter. If you feel air movement, water is getting through. Call (888) 635-0804 and we’ll inspect it free.
Yes, if the door frame has racked. The same expansive clay soil that binds a door in July also shifts window jambs. We reset the rough opening before installing the new unit, which corrects the underlying problem rather than hiding it. A free inspection will tell you what’s actually moving.
Target a SHGC of 0.25 or lower. Ontario’s Climate Zone 10 requires low solar heat gain, and west-facing glass catches the hottest part of the day. A low-SHGC dual-pane low-E unit can cut cooling loads meaningfully in a city where air conditioning runs half the year.
Because Ontario’s temperature swings are more extreme. When the seal fails, moisture enters the argon-filled cavity and condenses. The window loses insulating gas and the glass surface temperature fluctuates more. Ontario’s summer heat accelerates the failure. A fogged unit isn’t just cosmetic. It’s broken.
Not by code, but we recommend it for west- and north-facing openings that take the brunt of Cajon Pass wind events. PGT and CGI impact glazing adds wind-load protection beyond standard dual-pane. We quote both options side by side. Call (888) 635-0804 for exact numbers on your home.
Get Your Free Ontario Window Replacement Estimate
TruePane Windows & Doors serves Ontario with written quotes, fixed pricing, and a live person on the phone around the clock. If your windows are fogged, racked, leaking, or just throwing heat into a west-facing room, call (888) 635-0804. We’ll schedule a free estimate and walk you through every number on paper before anything is ordered. The pane is true or the job isn’t done. That’s been the rule since 2008.
Written by Dale Kessler, Owner at TruePane Windows & Doors, serving Ontario and the Inland Empire since 2008.



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