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About 35% of heat loss in an uninsulated home is through its walls 

  • Pre-1920 older houses are more likely to have solid walls. 

  • If a brick wall is more than 260mm thick then it probably has a cavity.

  • The bricks will usually have an even pattern with all the bricks laid lengthways.

  • If your house is a steel-frame or timber-framed building, or is made from pre-fabricated concrete, then you will need to ask a specialist insulation installer to advise you.


Cavity wall insulation explained

Many cavity walls can be insulated by injecting insulation material into the cavity from the outside. A specialist company will drill 22mm holes in the outside walls, inject insulation through the holes and then seal them with cement. The insulation material is usually either mineral wool or polystyrene beads, but polyurethane foam may sometimes be used instead.  However polyurethane foam cannot be topped up if needed in the future.  Costs are in the region of £20/m2.


Find an installer

Your installer should be a member of one of these organisations:


Useful Websites


You are responsible for validating all details before entering into commitments or taking any action and do so entirely at your own risk.

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