Double-pane windows
Two panes, a spacer, and a sealed gap — often filled with argon — are the baseline of a modern replacement in much of southern Canada. A low-emissivity coating cuts radiant heat leaving the room in January and, on a west wall, some of the heat coming in during July. Double pane is the right conversation for many main-floor replacements where the wall insulation, not the glass, is the weaker point.
A failed double-pane unit that is fogged between the panes is not repaired by cleaning. The seal is gone. If the sash is sound, that can be glass replacement. If the whole window is tired, it folds into window replacement.
Triple-pane windows
A third pane and a second gap add weight and cost, and they can make sense on a north wall, in a cold Manitoba winter, or in a room you refuse to curtain. They are not automatically the correct upgrade for a sheltered south window. We will say so. Triple pane also deepens the sash, which matters in an insert replacement where the old frame is shallow.
People ask for triple-pane windows in Manitoba because heating season is long. The honest answer is room by room. A house can carry triple pane on the exposed side and double pane elsewhere without looking unfinished, as long as the frames and the exterior colour match.
What we will not print as a promise
- A single U-factor, as if every size and coating were the same product.
- A percentage off your utility bill. Your furnace, insulation, and air leakage decide that.
- An ENERGY STAR partnership or a certification we have not been issued.
- A claim that new windows alone fix ice on a sill if indoor humidity is very high.
Frames and edges
Glass is only part of the heat path. A warm-edge spacer resists the cold line around the pane that shows up as a damp perimeter on old aluminum. Vinyl, fibreglass, and clad wood move heat differently and move with temperature differently. On a dark west elevation, frame colour is a durability question as well as a design one.
Casement and awning windows often seal tighter than a slider because the sash compresses against the weatherstrip when it closes. If air leakage is the complaint, operation belongs in the specification next to the pane count. See casement windows.
How this shows up on an estimate
The quote names the pane count, the coating approach, and the frame material for the openings we measured. You can compare two glass packages on the same openings instead of comparing a slogan. Patio and sliding doors are specified the same way: a large door is a large area of glass, and the package should be chosen on purpose.
Questions we hear on this work
Are triple-pane windows always warmer?
They can be, at the glass. Comfort in the room still depends on the frame, the installation gap, and the rest of the wall. We do not specify triple pane on every opening by default.
What is a low-E coating?
A very thin coating that reflects radiant heat. Different coatings favour winter heat retention or summer solar control. Orientation decides which conversation we have.
Will new glass stop my windows sweating?
It raises the interior surface temperature, which helps. Heavy humidity from cooking, showers, or a tightly closed house can still leave water on the glass.