Foundations and floor
Insulating under a suspended timber floor stops cold rising through the boards, and can often be done from below.
The short answer
- £1,400 to £2,500 for a suspended timber floor, depending on the house; doing it yourself from a cellar or crawl space costs only the materials
- About £55 a year saved in a semi, from £40 in a mid-terrace to £100 in a detached bungalow
- Decades to pay back at full price, so do it when the floor comes up anyway, after loft and walls
