Do I Have Cavity Walls?

Check your EPC

The simplest way to find out if you have a cavity wall type is to check the Energy Performance Certificate (EPC) of your property, if you have one.

Go to and select “Retrieve Report Using Property Address”.

Type in your postcode and select your property to download your EPC. The wall type and insulation will be displayed on the second page.

Check your bricks

If you don’t have an EPC on your property, you can check by looking at the brick pattern of your external walls:

Measure your wall

If the external walls have been covered you can also measure the width of the wall. Use a tape measure at a door or window to measure the distance between the outside wall and the inside wall.

If the wall is more than 260mm thick, it is most likely a cavity wall.

If it is thinner than 260mm, it is probably solid.

Even if you don’t have a cavity wall, you can still get warmer! Solid Wall Insulation can help you get warm and reduce the amount of heat you lose through your walls.