Following loft insulation, cavity wall insulation is the most cost-effective insulation measure, it can reduce the heat loss through walls by up to 40%. Cavity wall insulation involves filling the cavity within the walls of your house with insulating material. Your home is likely to be noticeably warmer following the installation of cavity wall insulation and you are less likely to suffer from damp or condensation in your home if it has cavity wall insulation.

Cavity wall insulation is made from mineral wool or polystyrene granules and is injected into the cavity between the inner and outer layers of brickwork that make up the external wall of your house. Grants are often available for this and it can pay for itself in just a year or two in reduced heating costs.