External Wall Insulation

External wall insulation refers to a layer of insulation that’s fixed to the outside of an existing wall. This layer will be finished either with a coat of render or with an alternative cladding material to protect it from the elements. 

This is a common method of insulating walls used by those with solid walls, where cavity wall insulation is impossible. That said there are some other situations where external wall insulation make sense.

Upgrading and adding insulation should be something anyone who wants to improve the thermal efficiency of their home should consider, but it still pays to be aware that no form of wall insulation is without some form of challenge — often centered around how your home deals with moisture. 

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WHAT ARE THE ADVANTAGES OF EXTERNAL WALL INSULATION?

There are many benefits to this type of home insulation. 

External wall insulation (EWI) is generally regarded as the most efficient form of wall insulation because the insulation is continuous without interruptions from internal walls etc. so there’s less risk of thermal bridging, cold spots and mold.

The depth of insulation can be relatively thick since there are fewer restrictions on space on the outer face compared to insulating cavities or internally,” continues Ian. “It should also provide better airtightness. Compared to internal wall insulation there’s also no loss of floor space to worry about and relatively little disruption. Plus it can work wonders giving ugly buildings a spanking new facelift!

Other benefits to consider include:

• It reduces heat loss and energy bills
• Fewer draughts and increased the sense of comfort
• It does not disrupt the house while being installed
• This type of insulation does not reduce internal floor area
• It allows walls to contribute to thermal mass (the ‘tea cozy’ effect)
• It improves not only weatherproofing, but sound resistance too
• It increases the life of the wall
• It reduces condensation on internal walls