Get Your Windows Ready in Summer
How One Decision Can Save You from Cold Winters and Rising Energy Bills
While it is +28°C outside and the last thing you want to think about is heating, this is actually the perfect time to take care of your windows.
It may sound illogical, but there is a simple explanation: replacing windows is not a one-day process, and the installation season in Ottawa is relatively short. If you start now, your home will already be retaining heat by the time the first snow arrives. If you wait until October, you may have to spend another winter with your old window frames.
Where Does Your Heat Go?
According to Natural Resources Canada, windows and doors can account for up to 25–35% of all heat loss in an average Canadian home during the winter.
For a home in Ottawa, where the heating season is long and temperatures regularly fall below –20°C, this is not just an abstract statistic. It represents a very real portion of your monthly gas or electricity bill.
The problem is rarely the glass itself. More often, it is what is happening around it: dried-out weatherstripping, a warped frame, or an air gap between the sash and the frame. Heat escapes through these invisible openings — heat that you are paying for without even noticing it.
You can easily determine whether your windows are the problem without calling a specialist. On a cold day, place your hand near the window frame. If you feel cold air even when the window is closed, that is where your heat is escaping.
Fogged-up windows or frost forming on the inside, squeaking or sticking when opening, and visible gaps between the sash and frame all point to the same conclusion: it is time to replace the window.
How Does an Insulated Window Actually Work?
A modern energy-efficient window is much more than simply “double glazing.” It is an entire system working together.
Multiple-pane glazing.
Between the panes is a sealed insulating chamber. In high-quality windows, ordinary air is replaced with an inert gas such as argon. Argon conducts heat less efficiently, helping keep warmth inside the home much more effectively during winter.
Low-emissivity coating (Low-E).
An extremely thin layer of metal, invisible to the eye, is applied to the glass and reflects infrared heat back into the room. In summer, it also reduces unwanted solar heat entering the home, so it works in both directions.
Warm-edge spacer.
The metal spacer between panes, which traditionally acted as a “thermal bridge,” is replaced in modern windows with a composite material known as a super spacer. This helps reduce condensation and frost around the edges of the glass — a problem familiar to many homeowners with older windows.
The frame.
Vinyl remains one of the most practical choices for the Canadian climate. It does not dry out, does not require painting, and can last for decades.
What Should You Look for When Choosing Windows for a Canadian Winter?
For the Ottawa–Gatineau climate zone, experts recommend:
• Triple-pane windows filled with argon — one of the most efficient solutions, with an Energy Rating of ER34; or double-pane windows with argon and an ER34 rating. These are energy-efficient windows designed for homes expected to remain comfortable and efficient for decades.
• ENERGY STAR certification for cold-climate zones (B and C) — confirmation that the window has been tested specifically for Canadian winter conditions rather than for average climates.
• A low U-factor — the lower the value, the better the insulation — along with an appropriately selected Solar Heat Gain Coefficient (SHGC). On the south and west sides of a house, a higher SHGC may be beneficial because it allows winter sunlight to provide free passive heating.
Heat loss through windows can be reduced by as much as 45% when old windows are completely replaced with certified ENERGY STAR models, while total home heating costs may fall by 15–25%, according to Natural Resources Canada.
• Energy Rating (ER) — the Canadian rating system that considers three factors at once: heat loss, solar heat gain, and air leakage.
How Much Can You Actually Save?
This is where the numbers become especially convincing.
For an Ottawa home where winter heating costs average approximately $2,500–$3,500 per year, the savings can amount to several hundred dollars annually — year after year, for as long as the new windows remain in service.
Why Make the Decision Now?
Replacing windows is not only about lowering heating bills.
It also means less street noise, no drafts near a child’s bed, no frost on the windowsill in the morning, and a completely different view through the window — without worn, cloudy, aging frames.
Summer is the one time of year when this work can be completed without rushing. You can schedule measurements, select the right model, wait for manufacturing, and have the windows installed in comfortable weather instead of on a freezing November day.
In addition to windows, you may also want to replace or install new patio doors, preferably ENERGY STAR certified, as well as front entrance doors, garden doors, 20-minute fire-rated doors, and doors between the house and the garage.
When winter arrives, you will not be hoping that your old windows and doors will “somehow make it through.” You will know that your home will stay warm — and that you will be paying considerably less to keep it that way.
Vitaliy Anufriev
Window and door installation specialist with 25 years of experience
613-224-7887