I’ve read widely varying estimates of the payback periods for wall insulation – which is correct?
A. There is no single figure that would be a good guide for all buildings. A great deal of the cost of installing wall insulation is in the cost of the adjustments that have to be made to accommodate it: changes in rainwater goods, eaves, verges, and window surrounds etc for external insulation and to cornices, skirting boards, wiring and plumbing for internal insulation. These will all vary dramatically from building to building. Meanwhile the benefits will also vary as the size, shape and construction of older buildings varies so much. Before embarking on a significant improvement such as wall insulation it is a good idea to instruct a building services engineer to run the proposal through a computer programme which can model the thermal performance of the building. The benefits of the insulation can then be predicted.
