How does it work?
Around a third of all heat lost from a poorly insulated home escapes from the walls meaning cavity wall insulation is often one of the most cost effective measures available to a home.
Generally, if your house was built in 1990 or afterwards, it will already have wall insulation. However, if your house is older, you may have cold, unfilled cavities.
A cavity wall is made up of two separate thin walls (usually built of brick and known as 'skins' or 'leaves') with a gap between them. They're usually held together by metal wall ties. Insulation is injected the the outer wall into the space between the inner and outer leaves of brick work.
