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Arches, oversized glass and heritage matches
GTS Windows & Doors designs and installs custom windows for homes across Kitchener, Waterloo, Cambridge, Guelph and the rural townships around them. Since 1986 we have taken on the openings a standard product line cannot fill: arches, circles, trapezoids under a cathedral ceiling, extra-large picture windows and faithful matches for older homes. We have templated shaped openings and fitted unusual units long enough to know where these jobs go wrong, and how to prevent it.
Strictly speaking, every replacement window we sell is made to measure. Custom work goes further, into non-rectangular shapes, sizes near the limits of what a frame or pane can carry, special exterior colours, grille patterns and profiles chosen to suit a heritage facade. That distinction matters, because it is where most of the extra cost, lead time and risk of an ordering mistake sits.
Our custom customers are homeowners restoring century houses in places like Galt and Elora, families building or renovating with an architect or designer, and general contractors and builders who need an unusual unit supplied and installed properly. Each project gets a full-size site template, careful checking of the manufacturer's drawings, and the same 20-year parts and labour warranty that covers all of our window work.
Plenty of companies call every window custom because it is built to your opening. That is true, but it describes a standard window in a non-standard size, and it should not carry a custom price.
We use the word for work that needs extra engineering, templating or finishing, where the manufacturer is building outside its normal catalogue. That includes:
Custom shapes are usually paired with standard operating windows, so it helps to know the basic types in our guide to window styles.
Half-rounds, quarter-rounds, eyebrows, full circles, trapezoids and pentagons are built from a template of the actual opening, not from a drawing. Most are fixed, though some can be made operable or set above a casement for ventilation.
In vinyl, curved frames are heat-bent, which sets a minimum radius we confirm with the manufacturer before ordering.
Large fixed units bring in light and views, but glass weight climbs fast, and a big sealed unit can exceed 100 kg. That affects frame choice, crew size and sometimes the need for lifting equipment.
Very large panes and glass close to floors or doors often need tempered or laminated glass under the building code and the manufacturer's limits, which we specify at the order stage.
Century homes have openings that have settled over many decades, so a rectangle measured at one corner will not fit. We measure diagonals and several points on each side, then either size the unit to the tightest dimension and trim the gap, or template it and order a shaped unit.
Exterior colour is the most common custom request. Beyond white and almond, most vinyl and fibreglass lines offer laminated or painted finishes such as black, bronze, grey and brown, and fibreglass handles dark colours with less heat movement than vinyl.
Colour and grille options sit on top of the standard frame and glass choices covered in our overview of new windows. The most requested finishes are:
A standard rectangle is ordered with a small shim gap on each side, and a few millimetres either way is easy to absorb. A curved head that is off by the same amount shows a visible gap or will not seat at all.
For arches and geometric units we make a full-size template of the opening in hardboard or heavy paper, mark the centre line and spring line, and send it with the order. Before the order is released, we check the manufacturer's shop drawing against our template and get your sign-off.
On new builds and additions we measure after framing, never from the plans, because framed openings rarely match the drawings exactly.
Add two to four weeks for orders placed between September and November. If your project has a hard deadline, such as an addition that has to be closed in before winter, we plan the templating date around it.
| Order type | Typical lead time |
|---|---|
| Standard style and colour, made to measure | 4 to 6 weeks |
| Custom exterior colour or woodgrain interior | 6 to 10 weeks |
| Arches, circles and geometric shapes | 6 to 12 weeks |
| Tempered, laminated or oversized triple pane glass | 6 to 10 weeks |
| Custom wood or clad wood units | 8 to 16 weeks |
Custom windows cost more than standard units, and the gap depends on how far from standard the order goes. These are typical 2026 installed ranges in Waterloo Region:
| Custom window | Typical installed range |
|---|---|
| Half-round or arched transom over an existing window | $900 to $2,500 |
| Full circle or oval | $1,200 to $3,000 |
| Trapezoid or pentagon gable window | $1,200 to $3,500 |
| Oversized picture window, over about 3 m² | $2,000 to $5,000 |
| Custom exterior colour | Typically 10 to 25% over white |
These are the kinds of custom projects homeowners and builders bring to us most often. Ask to see photos of comparable work when we visit.
Replacing a deteriorated arched wood transom above a front window or door, matching the curve and the original grille layout.
Trapezoid and pentagon units that follow a cathedral roof line, often mulled over rectangular windows below.
Turning two or three small windows into one large picture unit with operable flankers. This means widening the opening, handled through our window installation process with a building permit.
Windows with simulated divided lites and narrow sightlines for homes in or near a heritage district.
Most custom orders arrive 6 to 12 weeks after final measurement, and custom wood units can take up to 16 weeks. Fall orders take longer, so templating in summer is the best way to have a custom window installed before winter.
A standard style in a non-standard size usually costs little more than a catalogue size. True custom work, such as arches, circles or special colours, typically runs 30 to 100% more than a rectangular window of similar area. The difference comes from the extra engineering, templating and hand work.
Usually, yes. We copy sash proportions, grille patterns and sightlines using simulated divided lites or wood and clad-wood units, which are the details heritage staff typically review. If your home is designated or inside a Heritage Conservation District, read our permits and heritage guide before ordering.
Some can. ENERGY STAR certification applies to specific models listed by Natural Resources Canada, and some fixed shapes built from a certified product line qualify while specialty glass or unusual shapes may not. Check the product label or NRCan's searchable product list, and we will confirm the rating in your quote if a rebate depends on it.
Send us photos of the opening, or of the window you want to match, and we will book a site visit to measure and template. You will get a written quote with lead time and colour options.
Call or text226-806-0597