Commonly Asked Double Glazing Questions


Double Glazing


Triple Glazing



A Rated


How much do double glazing units cost?

There are a number of factors that can affect the cost of your double glazing and prices can range from around £500 for a single 60x90cm uPVC framed casement window to over £3,000 for a double-hung 180x150cm large sash window.  Some of the things that affect cost depends upon:

  • The type of window you choose.
  • The material – uPVC is usually the cheapest option.
  • How many windows you have fitted.

You can see some of the typical prices for the different types of double glazed windows and doors on our prices page.  This includes advice on how to make savings and will also give you useful information to help you avoid being overcharged when you reach the stage of contacting double glazing companies.

Can I replace double glazing myself?

Man installing double glazed windows

Man installing double glazed windows

All new double glazing is required to meet specific building regulations which must be approved by your local building control or by an installer who has been certified as able to verify the work under the Competent Person’s Scheme. All of this makes it inadvisable to fit your own double glazing.   Dealing with Building Control can be difficult and time consuming so we would recommend getting an installer who is registered on the Competent Person’s Scheme.

Can double glazing reduce noise?  It is soundproof?

Double glazing cuts out much more noise than single glazing because it has two panes of glass, this is why most people turn to double glazing.  If you choose triple glazing you will reduce the sound coming in even more. Different companies make different claims regarding the level of noise reduction you can expect.  For example, Anglian give a sound protection level of 31dB for it’s A-rated windows, but also claims a higher level of 36dB for its Safe and Sound range. Everest offers it’s own acoustic glass which they say will reduce sound levels by 40dB.

Will double glazing make my house damp or cause condensation?

If you see condensation build up on double glazing – be that windows or doors – it could be a sign that it is in need of replacing.  In a survey, 48% of people found that new double glazing does not steam up. It is worth remembering that all homes need to be ventilated and especially with older properties which often have built in mechanism to ensure air circulation, you could end up preventing moisture from escaping and that can cause damp.  You need to ensure that you think about ventilation when you purchase double glazing. It is worth looking at double glazing that have trickle vents built in to the frame to allow air to circulate. This is especially useful in the winter months when the cold air outside and the warmth inside can cause moisture collection on cold surfaces.  

Window configuration can also help, having one or two smaller windows means you can open them from time to time.  Tilt and turn windows and doors also allow you to let a small amount of air in but still keep the house locked and secure.  Some styles of windows will allow you to lock them when they are slightly open, all assisting in keeping the house properly ventilated.