November 15, 2016

We all want our homes to be as energy efficient as possible. An essential part of this comes from the style of the windows and doors, and the glazing options we choose to install in them.

Thanks to home renovation programmes, the energy efficiency provided by triple-glazing has been brought to the forefront. However, triple-glazing isn’t always the best, or most economical solution as other factors need to be taken into consideration, such as the age and the architectural importance of your property. In this blog, we seek to answer your questions on triple-glazing so that you are in a better position to make an informed choice when it comes to glazing.

What is triple glazing?

Triple-glazing is the use of three panes of glass in a glazing unit instead of the two panes used in double-glazing. This additional airspace and pane of glass can help to provide improved thermal insulation. Although triple-glazing is comparatively more expensive than double-glazing, many believe that the benefits outweigh the initial cost.

The efficiency of triple glazing

Window glazing energy efficiency is measured in ‘U value’ – the lower the better. To put this into perspective, a single-glazed window will have a U value of 5 plus, compared with triple-glazing that achieves a U-value of 1.0 and lower. But such U-values are only of benefit where they fit into a complete energy saving build, such as in a low energy house or a passivhaus build.

Windows are just one source of heat loss and heat will still escape from other parts of the property, such as the roof, walls and floors. If the rest of your property is poorly insulated, then you may not witness the return on investment from the additional cost of triple-glazing.

Challenges of triple glazing

Contrary to popular belief, triple-glazing does not reduce noise any more than standard (equivalent) double glazing.  Only when acoustic glass is fitted, whether it be to triple or double-glazing, will significant insulation against noise pollution be provided.

In addition, the extra pane of glass adds extra weight to the window. So, for instance, if you are thinking about having sash style windows, triple-glazing is heavy to lift and require larger balances to offset the weight, with the potential to  impact the look of the window.

Triple-glazing can also affect the amount of visible light within your home due to the additional layers of glass – the outside view may also look darker, especially if low-e glass is used. This has become less of an issue with the latest soft coatings.

There are complications when it comes to aesthetic features as the internal sides of the glazing units are often visible and not very attractive. Also, features such as internal blinds can be hard to source.

Top Tips

  • Due to improved manufacturing techniques and installation practices, new windows with double glazing built to replicate the originals, will be more efficient than those currently existing in a property.
  • Higher end double-glazing units can outperform cheaper triple glazing units offering longer life and better performance. As standard, our timber windows and doors are supplied with a high performance double-glazing system optimised for thermal efficiency, high light transmittance and acoustic performance.
  • Look for 3rd party certification of installers and manufacturers – this is a good indication of quality and trust.