Get your written quote
Retrofit and full-frame replacement since 1986
GTS Windows & Doors has replaced worn-out windows in homes across Kitchener, Waterloo, Cambridge, Guelph and the surrounding townships of Woolwich, Wilmot and Wellesley since 1986. If your windows fog between the panes, leak cold air or fight you every time you open them, we help you decide what to replace, what to repair and what can safely wait a few more years.
Most of our replacement customers are homeowners, but we also handle multi-unit replacements for property managers and landlords, with matching product across units and scheduling that works around tenants. We know the local housing stock very well, from Victorian brick in Kitchener's Victoria Park area to post-war bungalows and the 1990s subdivisions whose original builder-grade windows are now reaching the end of their service life.
Every replacement starts with an on-site measure and an honest look at the existing frames, because that decides whether a retrofit insert or a full-frame replacement is the right call. We supply ENERGY STAR rated windows, install them to the same flashing and sealing standard we use on new construction, and back the work with a 20-year parts and labour warranty. When a repair makes more sense than a new window, we will tell you that instead.
Not every sign means new windows. A single fogged pane in an otherwise sound frame can often be fixed with sealed glass unit replacement for a fraction of the cost.
Older brick homes near downtown Kitchener and in the older cores of Waterloo and Cambridge often have tall, narrow openings, deep masonry sills and original or early wood windows. Openings are rarely square, so we measure each one individually and choose profiles that suit the facade.
Some of these streets fall inside Heritage Conservation Districts, where window changes can need a heritage permit before work starts.
Bungalows, storey-and-a-halfs and split-levels from this era often still have original aluminum sliders or first-generation vinyl. Those frames conduct cold badly, so they sweat and frost in winter, and replacing them is one of the most noticeable comfort upgrades a house can get.
Homes from the region's big growth years have builder-grade vinyl casements and sliders that are now 20 to 35 years old. The usual failures are fogged sealed units, stripped crank operators and brittle weatherstripping across the whole house at once.
Three decisions shape every replacement window: style, frame material and glass. Our overview of new window options covers each product in depth, and here is the short version.
Casements and awnings seal tightest and suit most rooms, while hung windows and sliders fit traditional facades and tight spaces. Picture windows add light with no moving parts, and bay and bow units project out for extra space.
Vinyl is the value choice and covers most replacements, and fibreglass is stiffer and handles dark colours better. Aluminum suits slim modern sightlines, and wood or clad wood is chosen for heritage character.
Double glazing with a Low-E coating, argon gas and warm-edge spacers is the baseline we recommend. Triple pane windows earn their extra cost on north walls, bedrooms facing busy roads and homes chasing deeper energy savings.
Our rule of thumb: if the old frame is sound, retrofit is good value, and if there is any doubt about water or air at the frame, we recommend full-frame. The flashing, foam and air-seal method we use is laid out step by step on our window installation page.
A retrofit window fits inside the existing frame once the old sashes and stops are removed. It suits frames that are solid, dry and square, keeps interior trim and plaster intact, and costs less.
The trade-offs are slightly less glass, since the new frame sits inside the old one, and no chance to see the wall behind it.
Full-frame replacement removes everything down to the rough opening. We recommend it when frames show rot or water damage, when drafts come from around the frame rather than the sash, or when the old window was never flashed.
It costs more and means new interior trim, but it lets us repair the opening and rebuild the flashing and air seal from scratch.
Typical 2026 installed prices in Waterloo Region, including supply, installation, disposal and standard finishing. Our Kitchener window and door cost guide has whole-house examples and more detail on what moves the price.
| Window type | Retrofit (typical) | Full-frame (typical) |
|---|---|---|
| Vinyl slider or single hung, standard size | $650 to $1,100 | $950 to $1,600 |
| Vinyl casement or awning | $800 to $1,400 | $1,100 to $1,900 |
| Large vinyl picture window | $1,000 to $2,200 | $1,400 to $2,800 |
| Basement slider | $500 to $900 | $800 to $1,400 |
| Bay or bow window | Not applicable | $4,500 to $10,000 |
| Fibreglass frame (any style) | Add 20 to 40% | Add 20 to 40% |
| Triple pane upgrade | Add $100 to $300 per window | Add $100 to $300 per window |
Ontario's Home Renovation Savings Program offers $100 per rough opening for ENERGY STAR certified windows, with a minimum of three window openings. You need a home energy assessment before work starts and at least two qualifying upgrades, and eligibility depends on how your home is heated, so book the assessment before you sign a window order.
In Kitchener, replacing a window within its existing opening, with no structural change and no fire-resistance rating involved, does not need a building permit. Widening an opening or adding a window does, and our guide to window permits and heritage rules covers both.
Properties in Kitchener's Heritage Conservation Districts (Victoria Park, Civic Centre, Upper Doon and St. Mary's) and individually designated homes may need a heritage permit to change windows. We check before ordering, since heritage review can steer material and profile choices.
We look at every window inside and out and check the frames for rot, movement and past leaks. Each opening is measured on site at three points in width and height, because older openings are rarely square.
You receive a written quote listing each window, the installation method and the finishing included.
Replacement windows are built to order, typically in 4 to 8 weeks. September to November is the peak, so ordering in summer or late winter often shortens the wait.
A two-person crew usually replaces 8 to 12 windows a day by retrofit, or 4 to 6 by full-frame. We lay drop sheets, work one opening at a time and close each one before starting the next.
Old windows, packaging and debris leave with us, and we vacuum the work areas. Before we go, we operate every sash with you, show you the locks and cleaning features, and note anything that needs a follow-up visit.
Our 20-year parts and labour warranty covers the replacement work: leaks at the frame, drafts at the joint, and operating problems caused by how the window was installed. The manufacturer's product warranty separately covers the glass seal, frame and hardware, on terms that vary by product line.
If you might sell the home, ask about transferability, since some product warranties pass to a new owner and others do not. Every term is written into your quote.
Forty years of replacing windows in Waterloo Region homes, from century brick to 2000s subdivisions.
Workmanship and parts covered for two decades, in writing.
WSIB coverage and liability insurance protect you if anything goes wrong on site. We are also a SAWDAC member.
Rated 4.5 stars from 31 Google reviews by local customers.
Open Monday to Saturday 7am to 9pm and Sunday 9am to 5pm, so a measure can fit around your work day.
Often, but condition matters more than age. A 30-year-old vinyl window with a sound frame and one fogged pane may only need new glass, while one with a rotting sill, failed seals throughout and worn hardware is past saving. We will tell you which applies after looking at them.
Doing the whole house at once usually lowers the cost per window, since measuring, delivery and setup are shared, and it guarantees a matching look. Phasing works too, starting with the worst windows or one side of the house. Just keep later orders in the same product line and colour.
Late winter and spring are usually the easiest times to book, because the September to November rush is over and lead times tend to be shorter. Price depends far more on product and scope than on season, so the real benefit is scheduling flexibility.
Yes. We replace one window at a time, so each opening is only exposed briefly, and we use sealants and membranes rated for cold-weather application.
Not for a same-size replacement in the existing opening with no structural change and no fire-resistance rating. Widening an opening or adding a new window needs a building permit. Designated heritage properties and homes in a Heritage Conservation District may also need a heritage permit.
Call or request a quote online, seven days a week. We will measure every opening and give you a written quote, with retrofit and full-frame options where both make sense.
Call or text226-806-0597