Double vs Triple Glazed Windows: What’s Better?

If you’re looking to replace your windows, you probably have quite a few questions bouncing around in your head. What style would best match my home’s decor? What is the price difference between different types of windows? Are some windows better for airflow than others? There’s a seemingly endless amount of variation in types and styles of windows, so asking these questions is important for you to get the most out of your window purchase.

The question we tackle in this article is: What’s better? Double or triple-glazed (or triple-paned)  windows? The answer isn’t simple, as your personal preferences and budget are unique. However, by learning the difference between the two types of windows, you will have the knowledge you need to make the best decision for you.

What Are Double and Triple-Glazed Windows?

For a window to effectively insulate a room, it needs more than a single pane of glass to separate the interior of your home from the outside environment. That’s what double-glazed windows are for. They have two panes of glass that are set into the frame with space for air in the middle. The space in the middle is commonly filled with a safe and non-reactive gas like argon, krypton, or xenon, which is what gives the window most of its insulating capabilities. It’s basically a glass-air-glass sandwich designed to keep your home comfortable.

Triple-glazed windows use the same principle except there is another pane of glass, and therefore another space for the insulating gas. The glass-air-glass sandwich is now a glass-air-glass-air-glass clubhouse sandwich.

Differences in Energy-Efficiency

Naturally, the insulating effect of a triple-glazed window is more significant than its double-glazed counterpart. While double-glazed windows are no slouch when it comes to insulating your house, triple-glazed windows are more popular in northern climates like Canada and Scandinavia because of the extra layer of protection against extreme temperatures.

Fortunately for consumers, there are energy-efficiency ratings you can search to find out for yourself which windows are best for your home. When it comes to measuring insulation levels, you can compare a window’s U-value, which measures the rate of heat loss through the frame, spacer, and panels of glass. When comparing U-values, keep in mind that the smaller number means less heat loss. If you are unable or unwilling to compare and contrast U-values, it’s a safe bet to assume that a triple-glazed window is the better option if you’re looking for the best window for insulation.

Noise Reduction

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Have you ever been bothered by your neighbour’s loud music or the sound of cars zooming down the street outside your house? When you are, the go-to option to get some peace and quiet is to close your windows. Sound dampening is an often under-appreciated benefit of windows, and this applies to both double and triple-glazed windows.

The same reason why triple-glazed windows are more effective for insulation applies to sound reduction as well, but the difference isn’t as significant. Triple-glazed windows are usually a little quieter than double-glazed, but neither is designed specifically for soundproofing. If soundproofing is your number one concern, there are quality options beyond standard double and triple-glazed windows.


So far, triple-glazed windows have the edge over double-glazed, but that stops here. Because triple-glazed windows have an extra layer of gas and glass, they are thicker and heavier, making them more difficult to lift and install. If you hire contractors to do your installation, this may not seem like a big deal. But it’s not just the people lifting the window who need to be able to support its weight; your house does too.

If you live in an older home, you may need to strengthen the support structure before installing the window to ensure it can handle the extra weight.

Costs Differences

Because triple-glazed windows have more materials, provide more effective insulation and sound dampening, and are more difficult to install, they will cost you more money upfront. That applies to both the cost of the window itself and the cost of having contractors do the installation. But if you’re willing to spend some extra cash on the initial purchase, you can end up saving money in the long run because you will likely be lowering your future energy bills.

If you have specific questions about the pros and cons of double-glazed and triple-glazed windows, you can always ask a local window contractor for advice on your project.