Homes that were constructed after 1920 will have almost certainly have cavity walls where the external wall is made up of two layers that have a gap in between.

Cavity wall insulation is therefore when the gap gets filled to have an insulated property to keep warmth in and reduce energy bills.

It is felt that cavity wall insulation can save a household up to £135 per year and is relatively cheap to install with typical installation costing between £100-350. This therefore means that you can recoup your investment within three years.

If you are interested in cavity wall insulation then you will need to find out whether your property is suitable. Suitability often depends on whether the walls are unfilled, whether there is a 50mm wide gap to work within, whether the external wall is in a suitable condition and if the walls are not exposed to harsh weather conditions.

Walls are often unfilled if the property is older than ten years as newer properties tend to be built with cavity wall insulation already built in. If the property is suitable then every part of the wall will need to be filled with insulation so it is important that all walls are easy to access. If one of the walls is joined to a neighbouring property then a cavity wall barrier may have to be inserted to ensure that your neighbour’s property isn’t affected.

The insulation is installed by small drill holes being drilled at regular intervals along the outside wall and then a specialist machine blows insulation into the brickwork. The insulation material is usually made out of three materials which are mineral wool, beads or granules and foamed insulants. Your chosen installer will recommend the best material to use on your property but you should ask whether the material is energy efficient and complies to British Standards with a 25 year guarantee.

It is important to remember that cavity wall insulation needs to be carried out by an expert and is unfortunately not a job that you can do yourself. It is important that you choose a qualified company to do such work and it is recommended that you look for companies that are accredited by the National Insulation Association (NIA) or the Cavity Insulation Guarantee Agency (CIGA).

By choosing to insulate your cavity walls you will therefore be guaranteeing that your home retains heat and therefore reduce your energy bill and give you long-term energy savings.

Guest Article by Sarah Wain