What Are Window Panes?

Houses, offices, stores – all modern buildings contain at least a few windows. They provide ventilation, sunlight, protection, and an alternate escape route in case of fire. One part that’s on every single window is the window pane.

what are window panes

What are window panes? Here are some facts about windows to help make you an educated shopper.

Windows Then vs Now

We take for granted a shiny, see-through, glass-pane window that we can open and close at will. Paper, flattened animal horns, and oiled animal skins have historically been used for covering window openings in all different cultures.

In fact, it wasn’t until the 17th century that glass-pane windows were widespread in ordinary homes and businesses. It would be many more years yet until the process of creating large plates of glass, as you can see on nearly any commercial building today, was perfected for common use.

Anatomy of a Window

Window makers have their own set of terminology that you’ll want to be familiar with. Below are descriptions of each part of a standard glass window.


Window panes are the sheets of glass inside the window frame. They may be single-pane thickness, double-pane, or energy efficient. They can be plain glass or ornate.

They may come in a single large sheet, or there may be varying shapes and sizes of panes set within the frame.


The frame is the wooden, vinyl or fiberglass build which contains the window system. It’s comprised of the head, or the top horizontal piece; the jambs, or the vertical pieces, and the sill; the horizontal bottom piece.


The section of window frame which allows the pane to be moved up and down.


A sheet of mesh, often metal, which is stretched over the exterior portion of window to allow ventilation without bugs.


A flexible and tough strip of material which seals the connection of the frame and the sash, keeping air from getting out and rain from getting in.

Single Pane Windows

Single-pane windows are fairly self-explanatory: a single sheet of glass is hung in the window frame. These are very common to find in older homes.

While there’s technically nothing wrong with a single pane window, technology has come pretty far and there are newer models with double panes which are more efficient when it comes to noise and energy efficiency. Some single-pane windows may come with screens or removable “storm panes”.

Double Pane Windows

A double-pane window features two sheets of glass within the window frame. There’s a small gap in between the panes containing an insulating layer of argon gas. Not only does this make the window more efficient when it comes to heating and cooling your home, but it also makes for a tougher window.

double pane windows

When a hailstone or baseball connects with your window, it may only break the outer pane, leaving the inner pane intact to protect your interiors.

Additionally, the added thickness of a double-pane window blocks out more sound than a single pane – a great option if you live near an airport, train tracks, or a busy intersection.


How Can You Tell if Your Windows Need Replacing?

If your home is more than a few decades old, there’s a chance that the windows need to be replaced, but that’s not always the case. Window decay and disrepair can happen to any home.

It’s tempting to leave unsatisfactory windows alone to save money, but in the long run the eventual damage could end up costing a lot more. Examine your windows for these signs that they should be replaced.

Your House is Hard to Heat or Cool

Looking at your utility bill will provide you some clues, but you can also look at your windows. In the winter, can you stand near the windows without having to put on a sweater? If the panes are icy cold, the heat is disappearing when it gets close to your exterior walls.

You can also hold up a lit candle to the edges of the window frames – if the flame flickers, your windows are drafty and letting in the cold air.

Your Windows Are Difficult to Operate

If your windows can’t easily and smoothly be opened and closed, they should definitely be replaced. This is a health and safety issue all the way. You must be able to open your windows to ventilate when toxic fumes are present, or to escape fire or flooding.

If the window has to be held open with a prop, they are painted shut, or the wooden frame is too swollen to operate, the windows should be replaced as soon as possible.

Your Windows Are Leaking

Even a little bit of moisture coming in through the windows can cause mold, rotten wood, and warped framed. A poor installation or improper sealing could be the culprit, as well as plain old wear and tear over the years.

Leaky windows ought to be replaced to maintain your home’s integrity and prevent further expensive damages later on. You should also watch out for condensation building up on the interior window panes.

Your Windows Are Cracked

This one may seem obvious, but many homeowners assume that as long as the window still basically “works” it’s not important to replace it. However, a cracked and damaged window is more susceptible to shattering completely if bumped or struck, and your heating and cooling systems may start to run up heavy bills.

If there’s visible breakage and damage to your window panes or frames, it’s usually more economical in the long run to replace the window.

Are There Different Types of Window Panes?

Is one type of window pane better than another? We’ve already learned about single-pane and double-pane, but there are a few other upgrades to be aware of too.

You can get window panes tinted with a heat-absorbing coating, which reduces glare from the sun and keeps your house from getting overheated by sunlight.

Other window panes focusing on energy efficiency may come with low-emissivity coatings, which keep your heat from escaping your windows and reduces your heating bills. Reflective and selective coatings are also available, to keep out the sun’s heat while allowing its light to shine through.

Window panes aren’t just there to look pretty – although a well-made set of windows can certainly increase the attractiveness of your house. They can actually mean the difference when it comes to your home’s structural integrity and the cost of your utility bills. Equipped with new information on how window panes work and how to know when it’s time to replace them, you will be able to make the decision that is right for your home and family for years to come.

If you’re looking for more than just the window panes, Feldco is here to help. We offer full replacement windows installed by factory trained and certified professionals. Get a free quote now and see why over 500,000 homeowners have trusted us with their home improvement needs.

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