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  • Writer's pictureOakmont Glazing Systems Ltd

Triple Glazing - Is it worth the upgrade?

Over the last ten years people have become more aware of their energy bills. Over recent years, society as a whole has been more aware of the environment with everyone trying to do their own part to protect it. As such, there has been a growing demand for triple glazing with people keen to ensure their homes are not only warm and cosy, but also to make their homes more sustainable.

However, is it really just as simple as adding a third layer of glass? What really are the benefits of triple glazing? In this blog, we want to focus on the benefits of triple glazing, but also address many misconceptions to ensure you make the decision that is right for you and your family. After all, if you can save money on triple glazing, this money can be used elsewhere in your home.

Although this blog does cover certain aspects of glass, please refer to our blog specifically designed to address glass where you will get a more detailed explanation of types and options.

Thermal Performance

Firstly, it is important to understand how the thermal performance of the window is calculated. In this regard, you need to understand U values. In simple terms, the U value tells you how well any given window or door will retain heat. The lower the number, the better the performance. As an example, if window 1 had a U value of 1.6, but window 2 had a U value of 1.2, then window 2 is the more thermally efficient.

On any window, the glass will always be the most thermally efficient part, which is why people often focus on the glass and suggest upgrading to triple glazing. However, a chain is only as strong as its weakest link. You could have the best performing glass in the world, but if you put it into a poor window frame, the overall performance you get may not be anything worth shouting about.

With this in mind, many companies will advertise the glass U value (this is the best performing part, so sounds really good!) but the U value you need to ask for, is the overall window U value. This will then allow you to compare different windows and different companies to genuinely ascertain what performance you may achieve.

What you will often find, is many triple glazed windows do not perform nearly as well as some double glazed windows, so do not be led by the argument of double or triple glazing. Instead, focus on the overall U value you will get (remember the lower the better) as this is the part you will feel each and every day.

Sound / Acoustic Performance

We have many people ask for triple glazing simply because they are of the belief that this will assist them reduce noise inside the home, either from traffic, or a flight path or similar. The truth is, triple glazing in itself does not offer any advantage with reducing noise. This is due to how sound travels. To get sound to reduce, in simple terms, you need a mixture of thickness within your glass unit to ensure the sound cannot travel directly through the glass. Instead, the noise bounces around within the glass and reduces the amount of noise you hear as a consequence.

Whilst you can buy triple glazing with acoustic glass to help reduce noise, you shouldn’t buy triple glazing simply for this purpose. Similarly to the thermal performance, you will often find that a double glazed window, when designed correctly, will perform to much high levels when it comes to acoustic performance compared to a triple glazed window. In this regard, you need to ask your window supplier for the dB reduction you can expect, and once again, not just of the glass, but of the entire window. When it comes to dB rating, the higher the number, the better (just to confuse matters!)


Triple glazing will no doubt improve the thermal performance of any given window and when combined with a well-designed window system, the U values can be staggering low. If for example you wanted to build a new home and wanted to hit Passiv levels, then triple glazing would be required to achieve this.

If you are refurbing your own home and you want to future proof it to ensure you don’t need or have to replace windows again in years to come, then triple glazing is a good investment for the future. But as we mentioned at the start, focus on the U value you need to achieve and let that drive your decision on whether triple glazing is required.

In Summary

Triple glazing in itself is a good thing as it upgrades the performance of any given window. But don’t be fooled by shiny marketing material or a good sales pitch, as if you have a good quality window (let’s say an Alu-clad window - please see our other blog for more information on Alu-clad windows) then the double glazing performance achieved would be suitable for most home owners. As we said above, a chain is only as strong as its weakest link. If you buy the best window money can buy, but your walls and roof and every other nook and cranny of your home are not to that same level, then heat will find another way out and noise will find another way in.

We recommend spending some time to decide exactly what you want to achieve for your home and focus on what is important to achieve it. Remember, the lower the U value the more heat you will retain. The higher the dB rating, the more noise you will keep out. When you have decided what you need, draw a line in the sand and look for that target. Otherwise, you could keep spending your hard-earned money and not really feel any extra benefits.

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