What Era Windows (and Doors) are you Thinking About Replacing? 

Sometimes the home you have just purchased has older windows in it, and you’re not sure if they might still be effective. So, how can you tell when you should replace the windows? It is much easier to answer this question during the cold drafts of wintertime, but there are other signs.


Manufacturing advances mean new windows are energy-efficient, high-performing, and highly insulative. All this equates to approximately 15 -25% savings in heating and cooling costs. Feeling a cozy ambience in the wintertime without chilly drafts from your windows and doors makes your days and nights much more pleasant. 

You should replace the windows in your home if their original components would not be deemed energy-efficient after a repair or upgrade, or if the useful life of their extrusion, through ineffective original design, never was energy-efficient. That is not to say that every window should be replaced; you should consider upgrades and repairs to original dense-wood windows that have, so far, been cared for.

Read our article 10 Reasons you Should Consider Replacing all Your Windows at Once’


It’s good to know how much useful life is left in your existing windows so that you can financially plan. 

Generally, if windows have two layers of glass (also known as double-glazed windows), they have better insulating abilities than single-paned (or single-glazed) windows. If you know the windows are high quality, these double glazed windows shouldn’t need significant repair, upkeep, or replacement for 20-ish years from the time of installation. 


A brief history of the circa of windows on your house. Should they be restored, repaired or replaced?

Your house has circa 1870s- 1950s windows: 

Are your windows single-glazed and double-hung (top and bottom units sliding up and down) or casement (hinged at the sides) wood windows on a gorgeous heritage home? 

They will either require optimal restoration or, if that is not your priority, they need replacing now. 

Keeping a historical feel to your windows: historic wood is more dense than today’s wood and will last indefinitely with proper upkeep. Valued energy efficiency can be achieved with restoration.

If you wish to keep your original heritage windows, invest in adequately scraping away built-up layers of paint that lessen the windows’ insulative qualities. Repair the weights, pulleys and cords, add the best weather-stripping, and replace putty and thin glass. This restoration is a valid monetary trade-off to new windows, and you can achieve similar energy savings. Additionally, you might consider adding custom storm windows which increase efficiency more effectively than the poorly sealed 60s versions


Your house has circa 1950s- 80s windows: 

After WW2, materials other than wood were introduced for window extrusions. These were the early days of both vinyl and aluminum-framed windows. 

Vinyl windows were introduced first in Germany due to a scarcity of natural materials brought on by the second world war. In the late 1940s, the Germans looked at chemicals that could be extruded for window manufacturing. If your windows are made from the early 50s -90s vinyl, they need replacing. Vinyl windows have progressed from these early iterations, which were inclined toward cracking, warping, and discolouration, to today’s worry-free versions

Aluminum framed and glass-expansive windows were brought north by Canadians who spent the winter in warmer climes and desired those large-paned, Florida-styled windows all year round regardless of their suitability to our Canadian climate

They were usually slider window frames (or sashes) made from thin aluminum with narrow rubber seals that quickly froze as moisture condensed on the aluminum in the winter. These awful, yes awful, windows were great for warm climates but the cold-retention attributes of aluminum did not suit cold northern temperatures.

This not-learned lesson is repeating itself today largely due to Pinterest. Aluminum is not a material for windows in cold climates.


Your house has circa 1980s- 2000s windows: 

I grew up with wooden 80s windows. While better than aluminum ones, the wood used to make them was less dense and the frames thinner which eventually led to warping. Although you can repair these windows, it is time to replace them whenever you can financially afford it. 



Your house has circa 2000s- 10s windows: 

Since first invented in Germany in the late 1940s, vinyl for windows, by the 2010s, became less prone to cracking or warping, had a wider range of colours available, and even mimicked a wood appearance. 

The same was true for vinyl doors and siding. If your home has any vinyl from this era, you can breathe easily for another 5-10 years. However, you may want to take note of some of the telltale signs they are in their last days. Not all vinyl windows are manufactured with the same quality materials and parts.


Your house has circa 2010s- 20s windows:

Vinyl scientists, primarily out of Germany, continue to find ways to make sashes (individual component frames) and overall frames the most energy-efficient they can be. 

Combined with the technological progress of materials used for the gasket seals between windows, depending on the manufacturer’s quality, you should not have to consider a replacement for at least 20- 25 years. 



With a myriad of home renovations to consider, let’s identify the signs that indicate you should replace your windows. 

Widespread rot: It can happen quickly to older historic windows if painting and upkeep are not continued. Replace the rotted pieces, preferably with historic wood or replace the windows.

Broken seals: Condensation between double-glazed windows is the result of a broken seal which allows outside air and moisture to react with the temperature-retaining gas within. It is not inexpensive to replace the whole sash (required). Depending on the age of the windows, their efficiency at keeping cold air out, and their physical condition, it may be time to replace your windows.

How does the vinyl look from the outside? Vinyl window and siding extrusions are manufactured in the colour ordered, and while a quick paint job may last for a couple of years, if you’ve discovered a past owner painted the vinyl windows, it’s not a good sign for longevity.

If you have only one or two windows with an issue, you should ask a handyman with window and door experience to help repair the concern. Otherwise, Forest City Window & Door Ltd. has been a respected and proud London Ontario window and door installer since 1993.



We provide high-quality vinyl windows and doors (as well as other door materials) with attractive hardware options, all installed by our professionally trained teams.

Please contact us any time at (519) 659 6906 or online.


As of this writing, old PVC vinyl windows are not recyclable. In London, landfills will accept your vinyl extrusions and gas-filled double-glazing. Please ask your local city councillor about PVC vinyl recycling plans in London, Ontario and let’s get London recycling more of our construction waste.