Forty pounds of draughtproofing before four thousand of anything else
Draughtproofing first
About forty pounds and a weekend. Letterbox, keyholes, floorboards, and the gap under the skirting. Payback is measured in weeks.
Then loft insulation
About four hundred pounds and pays back in two to four years. Check what is there first; two thirds of lofts have some already.
Then the expensive things
Walls, windows, and heat pumps all have paybacks of a decade or more. Worth doing and not worth doing first.
