It is a fair question. Draught-proofing is one of the cheapest home improvements, but it is not magic, and it is worth being clear about what it does.
What the experts say
The Energy Saving Trust describes draught-proofing as one of the simplest and most cost-effective ways to cut heat loss, with savings that depend on the type of home and the heating system. Their published figures for a typical home are modest, in the tens of pounds a year for windows and doors, with an extra amount for blocking an open chimney. Figures change as energy prices change, so check their site for the current numbers rather than trusting a number you see in an advert.
Why the saving is only part of the story
Draughts do three things that cost you money or comfort:
- They let warm air out of the house, which your heating has to replace.
- They bring in cold air at floor level, so rooms feel colder than the thermostat says.
- They create cold spots, so you tend to turn the heating up.
Stopping them makes a room feel warmer at the same temperature. Many people find they can set the thermostat a degree lower without noticing, though that is a personal decision.
The biggest leaks first
| Leak | Why it matters |
|---|---|
| Open chimney | A very large opening straight to the outside |
| Letterbox | A permanent hole in an external door |
| Gap under an external door | Cold air at floor level |
| Window frames | Many small gaps added together |
| Loft hatch | Warm air rising into the roof |
Payback
A roll of tape, a brush strip or a chimney pad costs from a few pounds to a few tens of pounds. Even at modest savings, many items pay for themselves in a season or two, and the comfort benefit starts on day one.
What draught-proofing does not do
- It does not replace insulation. Loft, wall and floor insulation save more over time.
- It does not fix damp or condensation. Keep ventilation working.
- It does not cure an old, badly fitted door or window on its own.
A sensible approach
Draught-proof first because it is cheap and quick. Then, if you are planning bigger improvements, look at insulation. The two work together.
Start with the draught tape, a door seal and, if you have an unused fireplace, a chimney excluder.