Why Are Triple Glazed Windows Eco Friendly?

If you’re interested in net-zero living or eco-friendly lifestyles, you’ve probably heard about triple-glazed windows. They’re are the most energy-efficient type of windows in the market. Many new construction sites use them, but why are they eco friendly?

Triple glazed windows are eco-friendly because they have higher insulating properties than the other types of windows on the market. Thanks to these higher insulation properties, less heat travels through the windows, reducing the amount of energy needed for cooling and heating the building.

While this is the main reason why triple-glazed windows are eco-friendly, the explanation is a bit more complex than what we have just explained. In the next section, we will explain it in depth. During the rest of the article, we will compare them to other types of windows to get a better idea of why they are the most eco-friendly option. In addition to that, we will compare its insulation properties to other parts of the building, to prove how great they can be. Lastly, we will also explain certain characteristics that make them even more eco-friendly.

Why Are Triple Glazed Windows Eco Friendly? – The in-depth answer

As we just mentioned, insulation is not the only property that makes triple-glazed windows eco-friendly. Let’s have a look at all of them in detail.

Triple Glazed Windows Have High Insulation Values

Triple glazed windows always have higher insulation values than double or single glazed windows. While the specific value will depend on the characteristics of the window (coating, type of gas in between panes), when comparing equals, triple glazed windows will always have higher values.

This is very important in the performance of the home because windows are one of the weakest spots in buildings. So, your home will lose a lot of energy (be it warm air or cold air) through them. Minimizing these losses with a high-performing window will help your home become more eco-friendly.

As a Result of These High insulation Properties, They Help Save Energy

So, because of this high insulation characteristic, triple glazed windows are much better at keeping the interior temperature stable. If it is colder outside, triple pane windows will keep the warmth inside. If it is hotter outside, triple glazed windows will keep the cold inside.

Because of this ability to keep the temperature more stable, you don’t need to use your heating and/or cooling systems as much, which helps you save energy.

Also, when compared to old windows, triple glazed windows are excellent at stopping the air flow. If you have old windows at home, you will know what they do not close hermetically, which means that air is always flowing in and out of the house through the gaps between the operable window and the window frame. In new windows, and specially in triple glazed ones, this is solved and windows close extremely well.

It makes sense if you think about it. The manufacturer is putting a lot of resources into this type of window so that it insulates better the house. If then the heat is transferred any case because of the airflow, it wouldn’t make any sense to purchase this type of window. Having said that, new double glazed will also close hermetically and some single panes will as well.

How Do Triple Glazed Windows Compare To Other Types of Windows?

To get a better idea of how good these windows are, let’s compare them with other types of windows. All Weather Windows has a great table where they show the different types of windows and the properties they have.

For example, a double-pane window with a low E-coating and filled with argon gas has an R-Value of 3.8. The same window but with triple-pane has an R-Value of 5.4. If the triple-pane window has two Low-E coatings instead of only one, the R-Value goes all the way to 7.5. The higher the R-Value, the better insulating properties the window has.

And how does that compare to single glazed windows? Well, as you may imagine, the difference is higher. For single-pane windows, the R-Value is usually around 1. So, a triple-glazed window can have a 5/7 fold increase in R-Value compared to a single glazed window.

What does that mean in terms of heat loss?

The important thing, though, and the reason why triple glazed windows are eco-friendly, is that they reduce heat loss. Let’s have a look at the impact it has compared to the other types of windows, to better understand the impact. I will be doing it in the metric system, but the order of magnitude will be the same.

To calculate the average heat loss per unit area, we have to divide the temperature difference between the inside and the outside by the RSI (the metric equivalent of the R-Value) of the window.

So, let’s assume the interior of the home is at 20 ºC (68 ºF) and the outside is at 0 ºC (32 ºF), so there is a difference of 20 ºC (or 20 K). Let’s calculate what would happen with the three types of windows, but first, let’s convert all the R-Values into RSI values.

  • Single Pane Window: R-Value = 1 -> RSI = 1/5.678 = 0.176
  • Double Pane Window: R-Value = 3.8 -> RSI = 3.8/5.678 = 0.669
  • Triple Pane Window: R-Value = 7.5 -> RSI = 7.5/5.678 = 1.32

Now, let’s look at the heat loss for each window type:

  • Single Pane Window: Heat loss = 20 / 0.176 = 113.63 Watts per Square Meter of Window
  • Double Pane Window: Heat loss = 20 / 0.669 = 29.89 Watts per Square Meter of Window
  • Triple Pane Window: Heat loss = 20 / 1.32 = 15.15 Watts per Square Meter of Window

So, as you can see, the difference between single-pane windows and the other types is dramatic. In this case, where there is a temperature difference of 20 ºC (or 36 ºF), a triple pane window also performs twice as well as a double-pane one.

How Does A Triple Glazed Window Compare to Other Building Components?

Now that we have seen how different types of windows compare, it is also interesting to compare triple glazed windows to other building components.

As a standard, walls have a recommended R-value of between 13 and 23, so between 2-3 times better than a triple glazed window. Roofs, on the other hand, have a recommended R-value of between 30 and 60, so between 4 and 8 times better.

If you think the jump is dramatic, just think that the jump between single glazed windows and triple glazed windows is the same order of magnitude. That’s why installing this type of window is eco-friendly.

How to Make Triple Glazed Windows Even More Eco-Friendly?

Now that we have seen why are they eco-friendly, let’s have a look at some characteristics that make them even more eco-friendly.

Their Performance Can Be Further Improved With Special Coatings

As we mentioned earlier, the performance of the window depends a lot on its characteristics. A way to further improve its performance is by adding special coatings. These are usually can be low-emissivity. The number of coatings and their location will make a difference in the performance.

The Type of Frame Has Also an Impact on The Performance of the Windows

The type of window frame you use can also increase the R-Value of the window and, as a result, increase how eco-friendly the window is.

Fiberglass frames are an excellent choice because they insulate against heat and cold. Also, they do not expand or contract with temperature changes and because of their mechanical properties, can support big panes of glass with slim profiles.

Insulation within The Frame Can Increase R-value Further

Within some types of frame, it is an option to have foam insulation within it. The insulation is placed both in the frame and sash cavities and provides maximum thermal insulation and condensation resistance.

These three improvements can bring the R-value of a triple glazed window to 10, making it comparable with standard walls. An example of this type of window can be found in Alpen High Performance Products.


Triple-glazed windows are becoming an essential component of green living. Whether you’re saving money and energy via net-zero construction or you’re looking to reduce energy costs, they’re an excellent addition to your home.

Here’s a quick recap of what the post should’ve taught you:

  • Triple-glazed windows are eco-friendly because they can help reduce the amount of energy that is spent on heating and cooling your home.
  • The R-value difference between single-pane windows and triple-pane windows is 7-fold.
  • Despite its excellent performance, a normal wall has an R-value 2-3 times higher than a standard triple-glazed window.
  • With certain improvements, the R-value of a triple-glazed window can be increased to 10, which makes it comparable to standard walls.

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