If you’re planning to replace windows or carry out home improvements such as adding on a conservatory or orangery, you will probably be looking forward to the fresh, light and airy feel new glazing can generate.

However, there are other benefits to installing new windows, depending on whether you choose to go for double or triple glazed. Both have their own advantages so it is really simply a matter of personal choice in deciding which is right for you. Here, we look at the differences between them to help you decide.

The difference between double and triple glazed solutions

Most people will be familiar with the advantages of double glazed windows. As the name suggests, this is simply two panes of glass, sandwiched together with a thin space of air – or an insulating gas such as Argon – trapped in the middle. They offer better heat retention and help to block out external sound far more effectively than single glazing.

Triple glazing operates in a similar way, with the addition of a third pane of glass inserted into the sealed window frame. Traditionally, triple glazing has been most popular in colder countries, such as Scandinavia due to its ability to retain even more heat inside the home. However, more and more people are now opting for triple glazing in the UK, thanks to the other benefits it has to offer.

In addition to improved heat retention and therefore reduced energy costs, triple glazing also blocks out even more noise than standard double glazing, making it particularly useful if you happen to live near a noisy road or are often disturbed by external sounds. Triple glazing – due to the extra thickness created by the third pane of glass – is also more resistant to attempts to break it than other types of glazing. This could be an advantage if home security is an issue.

Can glazing help to reduce energy waste?

With energy costs steadily on the rise and now forming a sizeable chunk of many household bills, homeowners are often looking for ways to reduce their energy usage for cost as well as environmental reasons. While good quality double glazing is one effective way of doing this, it makes sense that triple glazing can go that little bit further in retaining additional heat inside your home.

U-values are the industry measurement used to denote the insulating effect of glazing. The lower the U-value rating, the more effective glazing is at blocking heat loss. As a benchmark, a brick wall would be considered to have a U-value of 2.0, compared to double glazed windows at 1.2 and triple glazed windows at around 0.6.

Controlling the temperature inside your home

While we’ve talked about the heat retaining properties of double and triple glazing, it’s not just what happens during the winter months you’ll need to consider when choosing the right windows for your property. Whatever your view of our ‘British Summer’, it is still that case that many homes in the UK can become unbearably hot when the warmer months arrive. Most common in houses with south or west facing windows where the sun shines in, this is known as the ‘greenhouse effect’ and it can make rooms really uncomfortable to be in.

To help address this issue, it is possible to improve temperature control through ‘solar gains’ in glass, measured in g-value. The lower the percentage of g-value a window offers, the better it will be at controlling temperature. Triple glazing often comes out top in this competition, with a g-value rating of between 35-63% compared to double glazing’s 73%.

Issues with condensation?

Condensation occurs when there is moisture in the air combined with a drastic difference in temperatures. If your home already demonstrates this problem, you may wish to look into how you can resolve the issue because, in the longer term, condensation can lead to wider issues with window frames and paintwork.

Well insulated homes can experience interior condensation when there is a contrast between the wall temperature and cold patches created by some windows. Conversely, triple glazing may reduce this effect because of its higher U-value, meaning there is less of a difference between the temperature of the rest of the house and the windows themselves.

How thick is triple glazing compared to double?

Naturally, having three panes of glass instead of two means that triple-glazed units are thicker. This has both advantages and disadvantages which you may want to consider.

As we mentioned earlier, thicker, triple glazing is more effective at blocking out noise and is harder to break. These can be significant advantages if reducing external noise and maximising home security are important to you.

However, glass isn’t the lightest of materials and it therefore follows that triple glazing is significantly heavier than other forms of glazing. This is something to consider depending on the structure of your property as it would need to be able to support the additional weight without sustaining damage.


The initial cost of installing double glazed windows is usually lower compared with triple glazed windows but you may want to consider other longer-term returns on your investment before making your final decision. Research suggests that replacing single or double glazing with its triple counterpart could reduce energy costs by up to 50%. This alone could make a higher initial investment worthwhile. However, do bear in mind that if the rest of your home is poorly insulated, you probably won’t make such a saving on your energy bills if heat is escaping elsewhere.

All in all, both types of glazing have many benefits on offer, with triple glazing considered to be an upgrade on double if it is suited to your property and budget. Very often it is simply a matter of personal choice. Please contact us if you’d like to speak to an expert for further information and advice.