Solid wall insulation
If your home was built before 1919, its external walls are probably solid rather than cavity walls. Cavity walls are made of two layers with a small gap or ‘cavity’ between them. Solid walls have no gap, so they let more heat through.
Solid wall insulation may be suitable for a variety of property types such as brick, stone, steel-framed and concrete construction.
Solid walls can be insulated – either from the inside or the outside.