External Wall Insulation (EWI)


External Wall Insulation (EWI)

External Wall Insulation (EWI)

External Wall Insulation is an extremely effective means of insulating solid wall properties to significantly reduce the amount of heat lost through the walls. The installation process involves fixing a layer of Expanded Polystyrene insulation (EPS) material to the external walls of a property, and covering it with reinforcement and a special render in a range of decorative finishes. These products are applied onto a range of specialist insulations designed specifically for external wall insulation systems which can be applied to many different substrates.

ACRYLIC render system are available in an extensive range of colours, finishes and textures and can be adapted to meet the expectations and design requirements of the architect and designer.  Using the anti-crack base coat technology provides excellent shock – proof resistance to impact.

DRY DASH render is a traditional render application commonly used. By this method, dry dashing aggregate is thrown onto the wet render to create a natural aggregate finish. Available in a wide variety of colours, sizes and textures.

MINERAL render systems offer a specially formulated mineral based render that can be applied to many different substrates. The finish retains the traditional appearance of a one coat render, with the advantage of a specially formulated top coat and anti-crack base coat technology. The system is available in a range of 48 standard colours, can receive a range of textured finishes with the added benefit that it is suitable for manual or mechanical applications.

You may need planning permission for external wall insulation, so make sure you check with your planning department before going ahead. It may not be suitable for the front of some period houses, but you may be able to insulate the back.




  • Can save approx., £475* per property per year (source: Energy Savings Trust)
  • Can be applied with minimal disruption to household and its occupants
  • No internal access is required
  • Improves the appearance of the property – potentially increasing the property’s value
  • Improves weatherproofing and sound resistance
  • Can make the building more airtight, reducing drafts and heat loss
  • Increases the life of the existing property by protecting the existing substrate from the weather
  • Reduces condensation on internal wall and can help prevent damp (but will not solve rising or penetration damp)








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