External Solid Wall Insulation
External solid wall insulation wraps the masonry exterior walls of the building within insulation so that rooms will cool down more slowly after the insulation is installed and hence is more suited to buildings that are heated all day rather than those that are heated intermittently.
Although the work can be completed whilst the occupants remain in the building this type of insulation is worth considering if the exterior walls are in need of repair or if major internal renovation is planned as there is a significant amount of disruption involved. Furthermore if the work is not carried out in conjunction with other repairs this form of insulation will have a very long payback period.
External wall insulation is usually installed as a composite system consisting of insulation material protected by render, cladding or tiles and the use of proprietary systems with British Board of Agrement certificates are recommended. . The installation of proprietary systems must be carried out by a specialist contractor. The Insulated Render and Cladding Association (external link) maintains a register of proven systems and installers and further information can be obtained on their website.
The overall thickness of the insulation and render or cladding is often quite substantial so care must be taken around rainwater down-pipes, window sills and where the walls meet the roof. Certain finishes may be vulnerable to impact damage and hence may require additional protection at ground level. A specialist contractor will employ the latest approved techniques and materials to deal with these problems.
Additional restrictions on the installation of external solid wall insulation may apply in certain local authority areas and particular care must be taken when considering installation within a conservation area or to a building listed as being of special architectural or historic interest. It is therefore highly advisable to check with the planning department before proceeding with any work. It is also recommended that approval is sought from building control before work commences.