To insulate your cavity walls, the installer will drill small holes, around 22mm in size, at intervals of around 1m in the outside wall of your home. With specially designed equipment, they then blow insulation into the cavity. Once all the insulation is in, the installer fills the holes in the brickwork so you'll barely notice them.
What is the insulation made of?
Cavity wall insulation can be made out of three types of materials: