Internal Wall Insulation

Internal Wall Insulation (IWI) is an approved Green Deal and ECO measure under the Building Fabric Measures category.

What is Internal Wall Insulation?

Internal Wall Insulation is most commonly installed in older homes with solid walls where Cavity Wall Insulation is not possible. Typically, insulation is laid between light-gauge steel channels or timber studs fixed to the inside of walls. The channels or studs are then most commonly covered by foil-backed plasterboard, (or plasterboard with a separate vapour control layer). Alternatively, composite boards of insulation and plasterboard are glued and/or mechanically fixed to the main wall. A further approach relates to ‘In-situ applied closed cell insulation’ that can be applied directly to the wall, between the studwork or to any thickness depending on the insulation value required and the space available.

Unlike External Wall Insulation, IWI does not affect the exterior appearance of the house, but it does slightly reduce room size. IWI is also not as effective at insulating walls as external wall insulation.

For further information on Green Deal Certification for Internal Wall Insulation, please contact our team on 0161 768 5807. Alternatively please email us at