Internally insulating your home will probably cost between £5,500 and £8,500, depending on how many rooms are being renovated and the type of material being used. Generally this is less expensive than external solid wall insulation because of the lower cost of materials and labour. A typical 3-bedroom semi-detached house using gas heating could save around £260 per year on heating bills by installing internal wall insulation whereas a detached house heating with oil could save around £450 per year.
A cut-away model of internal solid wall insulation.
1 | Surface coating (green)
This is the new plasterwork that covers the insulation layer. Just like a normal internal wall, it can be painted (green in this case) or papered
2 | Insulation (orange)
This is the layer that prevents warmth escaping through the outside walls of the house. In this case, rigid insulation boards have been used.
3 | Internal wall (white)
This is the old internal plaster which is now covered by the new insulation board and plasterwork.
4 | Windows
Ideally, the insulation board is fitted to the inside of the window recess to prevent cold patches developing where condensation forms. But, as is the case here, this is not always possible.
5 | External wall (brickwork)
From the outside, your property will look exactly the same.