Solid wall insulation can be applied to either the internal or external wall of a property. Most houses built before 1930 were built with solid walls. This means there is no cavity or space within the wall.
External or outside wall insulation is worth considering when repairing external walls. An insulated cladding is applied to external walls of the house. This form of insulation is expensive to install and it can take a long time to pay for itself.
Internal or inner wall insulation can be installed by placing insulating material behind a layer of plasterboard. This will slightly reduce the floor area of rooms and should only be considered as part of a major renovation of a property. Internal wall insulation has the same benefits as external wall insulation.
Prices and Payback Time for Wall Insulation
Wall Insulation | Cavity* | Internal* | External* |
Cost of fitting by installer | £280-380 | From £900 | From £1500 (if walls are being repaired anyway) |
Annual saving on fuel bills | £70-100 | £140-170 | £140-170 |
Cost recovered | 3-5 years | 5-6 years | 9-11 years |
*all information is based on a gas heated 3 bedroom semi detached house. Figures from the Energy Saving Trust.
