Energy Efficient Windows
Warmer rooms, no drafts, less condensation and lower energy bills. Here is what really makes a window energy efficient in an Ontario winter — the glass, the frame, the style and the installation — and how to tell if yours are wasting heat.
The Basics
What Makes a Window Energy Efficient?
An energy efficient window keeps the heat inside in winter and the sun’s heat outside in summer. It does that with a combination of things: coated glass, gas between the panes, an insulated frame, tight seals — and an installation that leaves no gaps around the frame.
No single feature does the job on its own. A window with great glass but a leaky frame, or a great window that is badly installed, will still let heat escape. That is why we look at the whole window and the whole install, not just the sticker.
At WindowFixers.ca every window we install is a custom-made, ENERGY STAR certified vinyl window, fitted and sealed by our own crew across Toronto, the GTA, York Region and up to Barrie.
What to Look For
6 Features of a Truly Energy Efficient Window
These are the parts that decide how warm your window really is. Want to know more about each type of glass? Read our window glass guide.
Low-E Coated Glass
A microscopically thin metal coating reflects heat back into the room in winter and blocks much of the summer sun’s heat and UV — without making the glass look tinted.
Argon Gas Fill
The space between the panes is filled with argon, a dense, harmless gas that slows heat moving through the glass far better than ordinary air.
Warm-Edge Spacers
The spacer that separates the panes is made with low-conductive material instead of plain metal, so the glass edge stays warmer and is less likely to fog or frost.
Multi-Chamber Vinyl Frames
Vinyl does not conduct cold like metal, and the hollow chambers inside the frame act as extra insulation, so the frame stays close to room temperature.
Airtight Seals & Styles
Compression weatherstripping and styles like casement and awning, which press shut against the frame, stop the drafts that waste the most heat.
A Properly Sealed Install
Even the best window leaks if it is installed badly. Every gap around the frame must be insulated and sealed inside and out — this is where many installs fall short.
The Benefits
What Energy Efficient Windows Do for Your Home
Lower Heating & Cooling Bills
Less heat escapes in winter and less sun heat gets in during summer, so your furnace and air conditioner run less.
No More Cold Drafts
Rooms stay evenly warm, and you can sit next to the window in January without feeling a chill.
Less Condensation & Frost
Warmer glass and frames mean far less water or ice forming on your windows on cold mornings.
A Quieter Home
Sealed, insulated glass also blocks a lot of traffic, neighbour and street noise.
Less Fading
Low-E glass blocks most UV rays that fade floors, furniture and curtains.
Better Resale Appeal
New ENERGY STAR windows are a selling point buyers notice and home inspectors comment on.
Ratings Made Simple
How to Compare Energy Efficient Windows
The quick version. For the details, read how to read a window energy label and window energy ratings explained.
| Rating | What it means | What to look for |
|---|---|---|
| ENERGY STAR | The window meets Natural Resources Canada’s efficiency standard for Canadian climates. | Look for the ENERGY STAR mark on the label or in the product details. |
| U-factor | How fast heat escapes through the whole window. | Lower is better — the most important number for Ontario winters. |
| Energy Rating (ER) | A single Canadian score that balances heat loss, solar heat gain and air leakage. | Higher is better. |
| Solar Heat Gain (SHGC) | How much of the sun’s heat comes through the glass. | Depends on the direction the window faces — we help you choose. |
| Air leakage | How much air sneaks through the window when it is closed. | Lower is better; casements and awnings usually score best. |
Double or triple pane? A good double pane window with Low-E and argon is already energy efficient for Ontario. Triple pane adds extra warmth and quiet for cold or noisy rooms.
Triple pane windowsWindow Styles
Which Window Styles Are Most Energy Efficient?
The way a window opens affects how well it seals. Here is how the styles we install compare.
Energy Efficient Replacement Windows
Signs Your Windows Are Wasting Energy
If any of these sound familiar, new energy efficient windows will make a noticeable difference:
- You feel a cold draft near the window even when it is closed and locked.
- Water, frost or ice forms on the glass or frames every winter.
- Fog or moisture is trapped between the panes and will not wipe off.
- Some rooms are always colder in winter or hotter in summer than the rest of the house.
- Your windows are single pane, aluminum-framed, or more than 20–25 years old.
- Your heating bills keep climbing even though your habits have not changed.
Still have old metal-framed windows? See our guide to aluminum windows and when to replace them.
What to Expect
How We Install Energy Efficient Windows
A clear, four-step process from first visit to final walk-through. Want the full details? See our window installation services.
Free In-Home Assessment
We look at your current windows, find where you are losing heat and measure every opening — then give you an upfront, all-in written price.
The Right Glass for Each Room
We help you pick the glass package, style and frame for each window, based on the direction it faces and how the room is used.
Custom-Built, Sealed Install
Windows are built to the exact size of each opening, then set level and square, insulated and sealed inside and out by our own crew.
Cleanup & Warranty
We finish the trim, haul away the old windows and back the job with a lifetime transferable manufacturer warranty plus our workmanship guarantee.
Why WindowFixers.ca
Efficient Windows, Installed the Right Way
Here is why Ontario homeowners trust us with their window upgrade.
Our Own Crews — Never Subcontracted
The team that quotes your home is the team that installs it, so the sealing and insulation are done right.
ENERGY STAR Certified Vinyl
Every window we install is ENERGY STAR certified vinyl with Low-E argon glass, backed by a lifetime transferable warranty.
Custom-Made to Fit
Each window is built to your exact opening, so there are no gaps to fill and no cold spots around the frame.
Local, Family-Owned, 10+ Years
A decade of installs from Toronto and the GTA up to Barrie, and 8,700+ happy clients, built almost entirely on referrals.
What Do Energy Efficient Windows Cost?
The price depends on the size, style and glass package of each window. See typical Ontario prices by style and material, and get a ballpark for your home in our free cost calculator.
Energy Efficient Windows FAQ
The questions homeowners ask us most about energy efficient windows.
Free In-Home Estimate
Upgrade to Energy Efficient Windows
Tell us a little about your home and we will schedule a free in-home assessment and give you an upfront, all-in price for new ENERGY STAR vinyl windows — with no pressure and no obligation. Serving Toronto, the GTA, York Region and up to Barrie.
Mon–Sun: 7:00 AM – 9:00 PM