Cavity wall insulation

Cavity wall insulation is insulating material fitted into the gap between the inner and outer leaves of a cavity external wall to reduce heat loss through that wall. It describes part of the wall fabric, not the same as the cavity wall itself, solid wall insulation, external wall insulation, internal wall insulation, render, a damp survey, a structural report, planning permission, Building Regulations completion, DNO approval, MCS certification or proof that equipment can be mounted or sited there.