How Often Should You Replace Your Windows? Signs It’s Time

You should replace windows when they stop doing their job: letting in drafts, fogging between the panes, rotting at the frame or getting hard to open. There’s no fixed schedule, because frame material, installation and exposure all affect lifespan, so the smart approach is to inspect your windows each fall and plan replacement before small problems turn into water damage.

What affects how long windows last?

Windows age at different speeds. These factors make the biggest difference:

• Frame material: vinyl, wood, fibreglass and aluminum each wear differently.
• Seal quality: the seal between glass panes holds the insulating gas in place.
• Installation: poor flashing and sealing let water into the wall.
• Sun and weather: south and west-facing windows take the most heat and UV.
• Care: wood frames need paint and caulking to stay sound.

The manufacturer’s warranty is a useful clue. It shows how long the maker expects key parts to last.

Signs it’s time to replace your windows

Walk through your home on a cold, windy day and check each window. Look for:

1. Fog or moisture between the panes. The seal has failed, and the window has lost much of its insulating value.
2. Drafts. Hold a lit candle or incense stick near the frame and watch for flickering smoke.
3. Heavy condensation or frost inside. Some is normal in winter, but constant moisture can mean poor glass performance.
4. Soft, rotting or cracked frames. Press wooden sills with a screwdriver to check for rot.
5. Hard to open, close or lock. Warped frames and worn hardware are a safety issue.
6. Rising heating and cooling bills. Old windows can be a big source of heat loss.
7. Outside noise. Newer double or triple-pane windows usually block more sound.

Window frame materials compared

Frame	Upkeep	Strengths	Trade-offs
Vinyl	Low	Affordable, good insulation, common in Ontario	Fewer colour options, can warp in extreme heat
Fibreglass	Low	Strong, stable, paintable	Higher upfront cost
Wood	High	Classic look, suits heritage bungalows	Needs regular painting and sealing
Wood clad with aluminum or vinyl	Low to moderate	Wood inside, weather protection outside	Higher cost
Aluminum	Low	Slim frames, strong	Conducts cold more than other materials

Look for ENERGY STAR certified windows rated for your climate zone. Ask about double versus triple-pane glass and low-E coatings, which help keep heat inside in winter.

Bungalow windows: what to keep in mind

Bungalows have most of their windows on one level, which makes replacement easier and often less costly per window than on a two-storey home. Many GTA bungalows also have basement windows that are small, old and drafty.

If you plan to finish the basement or add a second unit, think about upgrading basement bedroom windows to proper egress windows. Our guide on what an egress window is explains the requirements.

Also consider style. A postwar bungalow often looks best with simple, clean window shapes. A heritage bungalow may need wood windows or a design that respects local heritage rules.

Replace all at once or in stages?

Replacing every window in one project usually lowers the cost per window and gives the home a consistent look. It’s often the best choice when most windows are the same age.

Staged replacement spreads the cost out. Start with the worst windows, usually those facing north or west, or in bedrooms. Keep the style and colour consistent so the outside looks planned.

Either way, get at least three written quotes. Compare the window brand and model, the installation method, how they finish the trim and what the warranty covers.

Windows, energy efficiency and resale

New windows can make a home more comfortable, quieter and cheaper to heat. They’re also a selling point that buyers notice in listings and inspections.

Government energy-efficiency rebate programs change often, so check what’s available federally and in Ontario before you sign a contract. Our posts on EnerGuide ratings for bungalows and energy-efficient renovations explain how windows fit into a bigger efficiency plan.

Frequently asked questions

How do I know if my windows need replacing?

Common signs are fog between the panes, drafts, rotting or warped frames, heavy condensation and windows that are hard to open. Rising energy bills can also point to failing windows.

Can I replace just the glass in a window?

Often, yes. If the frame is solid and only the sealed glass unit has failed, a window company may be able to replace the glass alone at a lower cost.

What is the best time of year to replace windows in Ontario?

Spring through fall is easiest, because caulking and sealants cure best in mild weather. Many installers also work in winter by replacing one window at a time.

The bottom line on replacing windows

Replace windows when they show clear signs of failure, not just because of their age. Check them every fall, fix small issues early, and plan larger replacements with good quotes.

Thinking of selling soon? A free home evaluation can help you decide whether new windows are worth doing before you list.