Cavity walls were generally constructed from the 1920s onwards and usually consisted of two layers of brickwork (single skin and block) that are separated by a gap, which is commonly known as the cavity and can range from a width of approximately 50mm to 100mm on average.

Cavity wall insulation usually takes 3 – 4 hours to complete, and the most common method of installation is by drilling a number of holes in the mortar bedding around the brickwork, following the drill pattern from the manufacturer of the material and blowing the relevant type of material into the cavity between your inner and outer leaf (brickwork). The most common materials to be used are known as thermal bonded beads, fibre & foam.


The main benefit of cavity wall insulation is that it helps to prevent heat from escaping through your walls by approximately 35%.

On average, most households will save around £250 - £350 each year from cavity wall insulation alone, which does not consider the additional savings of installing loft insulation or double glazing.