About a third of the heat lost from an uninsulated home escapes through the walls. Since the mid-1980s, most homes have been built with wall insulation. The most common wall constructions found in Scottish homes are traditional brick or block cavity walls and solid brick walls.
In the case of cavity walls, the most common improvement is to install insulation by drilling a series of holes on the outside and injecting insulation into the cavity. This is highly cost-effective but requires a suitability assessment before installation. If the building is in a poor state of repair, over 11m high, or is severely exposed to wind driven rain, this method may not be appropriate.
In such cases, or where the wall is solid and does not have a cavity, internal or external wall insulation can be installed by adding a layer of insulation to the internal or external wall surface. Internal wall insulation is usually installed by fitting rigid insulation boards, or by building a stud wall and filling the void with insulation material, such as mineral wool.
External wall insulation involves fixing a track and layer of insulation material to the wall, and then covering it. A range of finishes are available which can improve the building’s aesthetics. These can be smooth, textured, painted, tiled, or finished with brick slips. For this method, a detailed suitability assessment must be undertaken to check the ability of the surface to carry the necessary loads.
Other wall constructions include rough stone, timber frame, steel frame, and system built, all of which can be upgraded subject to an assessment of suitability.