Pitched rooflights

Double Glazing vs Triple Glazing: Making the Right Choice

January 22, 2018

If you’re looking to replace your windows or have a rooflight installed, it can be difficult deciding whether to choose double or triple glazing. Each carries their own benefits, so it’s more down to personal preference, as opposed to a right or wrong answer.

Read on as we uncover five tips to help you decide whether you should go for double or triple glazing.

What Is Triple Glazing?

Triple glazing is exactly what it sounds like: it contains three panes of glass within a sealed frame, as opposed to the traditional two found in double glazing. In between the panes of glass you’ll find air, or insulating gas such as argon.

Triple glazing is most popular in cold climates, such as Scandinavia. However, they’re growing in popularity across the UK, as many people are looking to reap the benefits from it.

High Insulation Levels

Both double and triple glazing will help to keep heat in the house; but with its extra layer of glass, triple glazing goes one step further.

To determine insulation levels, you can compare something called a Ug-value: the lower the Ug-value, the better insulated the window is. As a benchmark, a brick wall has a Ug-value of 2.0; whereas double glazed windows are 1.2, and a triple glazed window is 0.6.

If you’re looking to keep as much heat in your house as possible (helping to slash those energy bills), then triple glazed windows are the way forward. That’s not to say that double glazing isn’t effective at keeping heat in – it’s just that it doesn’t do it as well as triple glazed windows.

Find out more about the Ug-values in our different types of glass here.

Temperature Control

It’s not just cold weather that homes across the country are trying to combat: come summer, many are prone to what is known as the “greenhouse effect”. This is particularly common in houses with south or west facing windows, where the sun shines in, making the room unbearably hot.

“Solar gains” in glass can help to reduce this heat, through temperature control. You can determine how well a window is at this with its g-value: the lower the percentage, the more effective the window is at controlling the temperature.

If you suffer from increasingly hot rooms in the summer, then triple glazing may be the ideal choice for you. Whereas double glazed windows have a g-value of 73%, triple glazed windows are between 35% – 63%.


Both double glazing and triple glazing offer unique benefits when it comes to costs; but it’s a question of how much you’re willing to initially invest.

The installation cost for double glazing is lower, but if you can pay the initial higher price for triple glazing, then you can reap the financial benefits later. Research has shown that if you replace single or old double glazed windows with triple glazing, you could cut your energy bills by 50%.

However, it’s important to take the rest of your house’s insulation properties into account, when working out the cost. If your home is old and poorly insulated, triple glazed windows won’t be as effective at cutting your energy bills.

If your home is already well insulated, or you will be taking steps to improve it; then cost-wise, triple glazing carries real benefits, as you won’t have “cold spots” (areas where heat is lost), like you would with double glazed windows. This will keep hot air trapped in, allowing you to use your heating less, and save money.


Condensation occurs when there is a drastic difference in temperatures. For houses that are well insulated, this is a contrast to the cold patches that double glazing creates, where heat escapes. That contrast can cause interior condensation.

Triple glazing on the other hand, reduces the likelihood of condensation: because it has a higher Ug-value, it means that there is less of a temperature difference between the glass and other areas of the house.

When deciding on double or triple glazing is especially important if your home is prone to condensation, especially as in the long-run, it can cause issues to window frames and paintwork. As condensation is caused when there is moisture in the air, activities like showering, cooking and drying your clothes inside can all be contributing factors.

Glass Thickness

As triple glazing is naturally thicker due to its third pane of glass, this carries both advantages and disadvantages, which should be taken into account when deciding between the two.

Thicker glass means your home is more secure, as it’s harder to break. It’s also more effective at blocking out noise – making triple glazing ideal if you live by a main road.

There is a downside to this however: triple glazed windows are heavier than double glazed. If you live in an older building, you’ll need to consider this, as the weight could potentially cause damage to your wall.

When comparing the two, triple glazing appears to be building on the benefits of double glazing. However, each carry their own advantages and disadvantages, which is why it can be difficult deciding between double or triple glazing.

Find out more information on our double and triple glazed rooflights here, or if you’d like to speak to an expert, simply give us a call on 0116 269 6297.