It won’t be wrong to say that triple glazed windows haven’t gained as much popularity in the UK as is the case in other, colder countries. Colder countries such as those in Scandinavia witness extreme winter weather conditions and this is the reason triple glazed windows have been a standard fitment in those countries. UK residents do not have to endure such harsh conditions but still, the winter months are too cold and you also have to contend with the ever-increasing energy prices. While insulating the floors, walls and roof of your home should keep your house warm during those cold winter months, neglecting the windows in your house can lead to condensation as well as cold spots.

Triple Glazing – Points to Consider

There are many advantages of installing triple glazed windows in your home. However, not all the triple glazed windows sold in the market are the same. In order to make the right choice and to derive the maximum efficiency from a triple glazed unit, you need to make sure that there is a 16 mm gap between the glass panes and argon gas is used in these gaps. It’s an inert gas known for its low heat transmission rates. Lowering the gaps between the glass panes of the sealed unit will affect its efficiency negatively. You can still achieve the same efficiency but only by using expensive alternatives such as krypton gas.

In order to obtain the maximum efficiency from a triple glazed unit, you should have 4 mm thick glass panes sitting 16 mm apart. If you take these gaps and thickness of glass panes into account, the total comes to 44 mm in width. There is also significant difference in the u-values between a double glazed unit and a triple glazed unit. The u-value for a double glazed unit comes to 1.1 at the centre of the pane whereas the corresponding number is 0.62 in case of a 44 mm wide triple glazed unit.

Advantages of Triple Glazing

A double glazed unit has 2 glass panes with an inert gas separating these 2 panes whereas there is an additional glass pane in a triple glazed sealed unit. Addition of this glass pane enhances the overall performance of a triple glazed unit significantly. The advantages are as follows:

  • First and foremost, it offers an additional barrier to keep you safe from the harsh outside weather.
  • Thermal transmittance is further reduced with the help of the additional spacer bar.
  • A triple glazed window is more secure compared to a double glazed window, especially with the use of toughened glass in the middle pane.
  • Sound insulation is generally better in a triple glazed unit when everything else remains the same.
  • Triple glazed sealed windows achieve the best energy rating, A++.

Disadvantages of Triple Glazing

While there are a number of advantages of triple glazed units, there are also some cons. The biggest problem you will come across is the condensation on the outermost glass pane. This condensation happens as the outermost glass pane does not get enough heat from the warmer air flowing inside your house. This allows the glass to reach dew point which means it becomes lower in temperature when compared to the temperature of outside air, and that leads to condensation.

You will see condensation generally after a cold clear night. Light misting is the most appropriate term to describe the type of condensation you will witness. Contrary to expectations, it begins from the centre of the glass pane and not on the edges. This is due to the reason that some heat gets transmitted through the spacer bar and the frame, which keeps the edge of the glass pane warmer as compared to the centre.


In conclusion, I would like to say that triple glazing offers a number of advantages and you should definitely consider replacing all the existing windows in your house with triple glazed units. You will have to spend extra money but you should be able to save enough money in the long run through higher energy efficiency to recoup your extra investment. Your property will also go up in value as your home will be much more attractive to potential buyers. Call us at KJM Group now to get a free estimate today. Don’t forget to ask for the price of upgrade to a triple glazed unit in addition to the price of double glazed window rated A.