Supply Chain Advice Pack: External Wall Insulation - assessing and design
Introduction
External Wall Insulation (EWI) is a retrofit solution that involves applying insulation material to the exterior of a building’s walls, typically finished with a protective render or cladding system. It helps to improve energy efficiency by reducing the amount of heat escaping through external walls which, according to the Energy Saving Trust, can account for up to 33% of total heat loss in uninsulated homes. EWI can lead to lower energy bills, especially when combined with other retrofit measures.
Published: September 2025
Contents
Welcome to the Supply Chain Advice Pack: External Wall Insulation - assessing and design
External wall insulation (EWI) can be one of the most effective methods for insulating a dwelling for several reasons. While it can be costly and may cause some disruption during installation, there are compelling reasons why EWI is often chosen as the preferred insulation solution for certain types of properties.
Download the PDF below to access this Advice Pack.
Readers that would like this document in a more accessible format should contact rise@turntown.co.uk.
To be kept up to date with future Advice Packs, resources developed for businesses working in retrofit, and upcoming training and events, please join the RISE supply chain mailing list. You'll hear from us monthly, with relevant updates and information.