Double Glazing vs Triple Glazing: Making the Right Choice

Double Glazing vs Triple Glazing: Making the Right Choice

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 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 contains three panes of glass within a sealed frame, as opposed to the traditional two panes found in double glazing. In between the panes of glass you’ll find argon gas and in some cases krypton gas, which is denser than air and has far better insulating properties.

Triple glazing is most popular in cold climates, such as Scandinavia. However, the option of triple glazing is growing in popularity across the UK, as many people are looking to help improve thermal efficiency and ultimately make long term savings on energy costs.

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, which measures the rate of heat loss through a panel of glass. To explain, the lower the Ug-value figure, the better insulated the window is. A double glazed window will usually have a Ug value of around 1.2, and a triple glazed window can be as low as 0.6. This offers the opportunity to significantly reduce the heat loss through windows by specifying triple glazing.

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.

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 south-west facing windows, where the sun shines in for most of the day, making the room very hot.

Solar control glass or adding tints to glass can help to reduce this heat, through temperature control. You can determine how well a window is at controlling solar heat with its g-value: the lower the percentage, the more effective the window is at reducing the amount of solar heat coming in to the property.

If you suffer from increasingly hot rooms in the summer, then triple glazing may be an ideal choice for you. You could combine this with solar control glass or by adding a tint for maximum effect.



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 are likely to reap the financial benefits over time.

It is important to take the rest of your house insulation properties into account, when working out the relative cost benefits. 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 are less likely to have “cold spots” (areas where heat is lost).

On the flipside, having well insulated windows means you will also maintain a cooler climate inside your property in the summer, which in turn means that you can save on the costs of running air conditioning or fans.

Glass Thickness

As triple glazing is naturally thicker due to its third pane of glass; thicker glass can help to block out noise – making triple glazing ideal if you live near a main road.

There is a downside to this however: triple glazed windows are heavier than double glazed, which can make the handling and installing of triple glazing slightly more challenging. If you live in an older building, you may need to strengthen the structure to accommodate the increase in weight, this may be helped by specifying double glazing, to reduce the weight. In most cases however, this will not be an issue.

There are clearly benefits to both double and triple glazed roof windows.  Both help to provide more light into your property and both can add a contemporary look and feel to your building project.

The choice is a personal one and can also depend on the weight that can be accommodated as part of the build project, budget available and your long-term requirements.