How cavity wall insulation works

If your house was built post 1920 then the chances are that your house's external walls were built using 2 layers of brick with an air-filled cavity in between.

By filling the gap between the 2 layers of brick, you can reduce the amount of heat that escapes your house. The insulation will also stabilise the temperature inside your house by insulating the house from temperature changes outside. This means that insulation will keep the house cooler when its hot outside.

The Cavity Insulation should meet British Standard 8208. If you're hiring a contractor to carry out the work, check to make sure they have the relevant certifications (British Board of Agreement Cert). The certification indicates that they work to high standards.