Cavity wall insulation can either be installed during the construction of the property or else it can be installed afterwards, often known as retro-fit cavity wall insulation. All modern buildings are now built with cavity wall insulation, but older buildings normally just have a cavity. Approximately a third of the heat in a house escapes through the walls and so having cavity wall insulation can soon pay for itself.

Here is a typical building site, you can see that there is a layer of cavity wall insulation being added as the wall is built up. This will help to insulate the house tremendously and will save a large amount of money from future heating bills.

Here is the insulation from a different angle.

This is the very top of the wall where the building timbers have been attached. You can see that the insulation goes right to the top.

Having cavity wall insulation installed into a cavity in an older home is often carried out be specialists who have the correct equipment and so it is not a DIY job. There are a few different types of insulation that are blown into the cavity, one is made from mineral wool and the other one is made from polystyrene beads. For an average house it will cost £250 to have it installed and so it should pay for itself within two years.