Insulation and draughts

Cheapest first

• Draughts. Seal gaps around doors and windows, fit a letterbox brush and keyhole cover, fill gaps between floorboards and skirting, and block unused chimneys with a removable chimney balloon or cap.
• Loft. The usual recommendation is about 270mm of mineral wool, laid across and between the joists. If you store things up there, raise the boarding so it doesn't squash the insulation.
• Pipes and cylinder. Lag hot water pipes in unheated spaces and give an old cylinder a jacket if it doesn't have factory foam.
• Cavity walls. Many houses built after the 1920s have a gap between two layers of brick that can be filled from outside in a day. Your EPC says whether yours are filled.
• Floors. Suspended timber floors can be insulated from below, from a cellar or crawl space, or by lifting the boards.
• Windows. Secondary glazing costs less than replacement windows and is often allowed where new windows aren't, as in listed buildings.
• Solid walls. Older houses with solid walls can be insulated inside or outside. It is the most effective and most disruptive job on this list, and worth doing when you are already redecorating or re-rendering.

You don't have to finish first

You may hear that a home must be well insulated before it can have a heat pump. Insulation helps, but the installer's heat loss calculation sizes the heat pump for the home as it is. Do the cheap jobs first and don't put off a heat pump for years waiting to do the expensive ones.

Keep the air fresh

Sealing gaps also cuts the fresh air coming in. Keep window trickle vents open, use extractor fans in the kitchen and bathroom, and watch for condensation or mould in the months after draught-proofing.

Help with the cost

Free or discounted insulation is available to many lower-income households, and in some areas to anyone in a home with a low EPC rating. Paying for it lists the schemes and checks which you might get.