If your home has solid walls rather than cavity ones then insulating them is a great way to upgrade their thermal efficiency. But it’s worth bearing in mind the pitfalls that can undermine your energy savings and cause other problems.

Traditionally external wall insulation UK wall insulation (EWI) has involved a layer of insulation boards fixed to the existing walls, then clad with sand and cement render, timber cladding or other weatherproof coatings. The insulating material can be mineral wool such as Rockwool or synthetic materials such as PIR, PUR or EPS boards.

A key problem with this approach is that it can lead to ‘cold bridges’ around doors and windows, allowing heat to escape through these weak points. This can also affect the draughtproofing of your property and could lead to moisture penetration and damp problems.

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Another issue with EWI is that it can make your existing bricks more permeable – allowing water vapour to pass through and evaporate away. This can be a good thing if your house is draughty and the dew point is low, but it will have a negative impact on the energy performance of your walls if the dew point shifts inwards and you end up with internal condensation and damp.

Finally, you should be aware that significant building changes like EWI require planning permission – and this will be even more important if you live in a listed or conservation area property. The first step should be to seek pre-application advice from the local council before you contact insulation companies. You should also bear in mind that erection of scaffolding and the removal and replacement of any pipes or cables fixed to your wall are additional costs which cannot be avoided.