Condensation on double glazing. Tips and Advice.

by | Jul 28, 2015 | Homeowner Advice

New double glazing is marketed as being an excellent solution to making your home more comfortable, reduce heat loss, lower your energy bills and of course give you new and more secure windows and doors.  Another benefit you will often be told about new windows and doors is how they will reduce condensation. Some mis-informed window companies might tell you that your new double glazing will completely eliminate condensation.

In properties old and new, it is worth knowing what causes condensation.

In properties old and new, it is worth knowing what causes condensation.


It is important to know that condensation can never be completely eliminated. There are several factors that can cause condensation in the home. In this article we give you our advice and experience.

What causes condensation in the home?

It is important to differentiate between a failed double glazed unit and a condensation double glazed unit.
A double glazed unit has “failed” and needs replacement if you see condensation in between the two panes of glass. In most cases this means that the seal around the double glazed unit has failed and the glass needs replacement.
Some window companies may suggest you change your window but if it is only the glass that has failed, this can easily be replaced into your existing window frames.
Older double glazed units do not have the same sophisticated manufacturing techniques as new glass units therefore the failure of glass is far less common nowadays.

What about condensation on my windows and doors?

It is very important to remember that how we live in our homes has a great bearing the moisture content and, in turn, the forming of condensation.
Modern flats are often drying out for many years after they are built and this can cause condensation. Also in flats and apartments, we will often use living spaces where houses have utility rooms and additional rooms. Drying washing in the home is another factor.
Our basic living needs such as showering, cooking and even moisture we release when we sleep can cause condensation.
We recommend you always leave any trickle vents in your windows and doors in the open position. They are designed to provide a consistent air flow. Many people will put their hands up to the trickle vents, feel cold air and close them. Always keep these open.

Condensation on new double glazing.

There are times when you may see condensation on the outside of your double glazing. This is common during Autumn in particular.
If you do see condensation on the outside of your windows, please be assured this is normal and is simply your brand new windows that are very energy efficient windows doing their job. The glass used today in modern double glazed units is very sophisticated and is designed to work with your multi chamber pvcu, or thermally insulated aluminium frames.
Modern double glazing is now far more energy efficient than ever before. With sophisticated coatings on glass units, combined with warm edge spacer bars and argon gas between the glass your new windows and doors now do a great job of retaining the heat in the home and keeping the cold out.
So if you’re wondering why you are seeing condensation on your new windows on the outside it is physics dictating that a colder surface externally than one internally will condensate.
This of course varies from property to property and you may not see any at all, but if you do, it is nothing to worry about.
Please contact us if you would like more information about your windows and doors.