Cavity Wall Insulation (CWI) is used to reduce heat loss through a cavity wall by filling the space with material that will help prevent heat escaping. This is one of the most cost effective things you can do for your home and could save you up to £275 per year depending on the size of your home.


More than a third of all heat lost from uninsulated homes escape through the walls. This is due to the fact that heat naturally flows from a warm area to a cold area which is particularly problematic during the winter months. CWI can help prevent this.


If your house was built after 1920, it is likely to have cavity walls. For an existing building without cavity wall insulation, it can be injected with a fibre typically glass fibre wool or rock wool panels, which is blown into a cavity through drilled holes until the space is filled with insulation materials. These materials work by immobilising the air within the cavity, preventing convection and can reduce the overall energy costs for the space.


Is cavity wall insulation suitable for your home?

Your home will usually be suitable for cavity wall insulation if it meets these criteria:

  • Its external walls are unfilled cavity walls.
  • Your cavity is at least 50mm wide.
  • The masonry or brickwork of your property is in good condition.
  • It is more than 10 years old (most newer houses will have insulation already).
  • The walls are not exposed to driving rain.

For more information about our services, to get a free quote or to talk us about your project, simply contact one of the SPMS team and we’ll get back to you ASAP.