Professional draught proofing costs around £20 to £60 per door or window and £250 to £700 for a whole house, with a chimney balloon or cap at £60 to £250. It is the cheapest energy measure there is and the fastest to pay back: the small items recover their cost within a winter, a whole house package within a few. It is 0% VAT, and our own team fits it.
Key takeaways
- Typical cost: £20 to £60 per door or window, £250 to £700 for a whole house, £60 to £250 for a chimney balloon or cap.
- Draughts and uncontrolled ventilation are typically 10 to 20% of the heat loss in an older home, so the saving is real even though the job is small.
- The cheapest items (letterbox brush, loft hatch seal) pay back within a single heating season.
- Never seal trickle vents, extractor fans, air bricks or the vent for an open flue appliance. Draught proofing is about gaps you do not need, not the ventilation you do.
- Draught stripping is 0% VAT until 31 March 2027 as an energy-saving material.
- Do it before, or alongside, bigger insulation. It costs a fraction of wall insulation and improves comfort on day one.
How much does draught proofing cost?
These are indicative prices for a professional fit in London and the South-East, supplied and fitted. Materials are cheap; most of the price is the time it takes to measure each gap and fit a seal that closes it without stopping the door or window from working.
| Item | Indicative cost fitted | Notes |
|---|---|---|
| External door (brush or compression seals, threshold strip) | £20 to £60 | Front and back doors first; they are usually the worst gaps |
| Window (compression strip to the opening sash) | £20 to £60 per window | Old timber sashes and casements benefit most |
| Letterbox brush or flap | £10 to £25 | One of the fastest paybacks in the house |
| Loft hatch (seal and a compression latch) | £20 to £50 | Warm air rises straight into the loft through an unsealed hatch |
| Chimney balloon or cap (unused open fireplace) | £60 to £250 | Cap needs roof access; balloon does not. Leave a small vent |
| Skirting and floorboard gaps | £50 to £150 per room | Worth doing with floor insulation if the boards are coming up anyway |
| Whole house package | £250 to £700 | Every external door and window, hatch, letterbox and the obvious gaps round pipes |
A Victorian terrace with sliding sash windows sits at the top of the range; a 1980s house with uPVC windows that already have seals sits at the bottom.
How quickly does draught proofing pay back?
In an older, uninsulated house, air leaking in through gaps and out through others typically carries away 10 to 20% of the heat you pay for. The exact saving depends on how draughty the home is to begin with, how warm you keep it and your tariff, so treat these figures as indicative rather than a promise.
| Measure | Indicative cost | Indicative annual saving | Payback |
|---|---|---|---|
| Letterbox brush and keyhole cover | £15 to £45 | £10 to £25 | Under one winter |
| Loft hatch seal | £20 to £50 | £10 to £30 | One to two winters |
| Chimney balloon on an unused open fire | £60 to £250 | £30 to £80 | One to three winters |
| Front and back doors | £40 to £120 | £20 to £50 | One to three winters |
| Whole house package | £250 to £700 | £60 to £150 | Two to five winters |
A loft top-up at £400 to £900 saves more pounds a year, but nothing gets its money back as fast as draught proofing, and it is the only measure you feel the moment the installer leaves.
Where do draughts come from?
Most people can name the front door and the sash windows. The gaps that surprise them are the ones they cannot see from the sofa.
- Suspended timber floors. Cold air moves through the void under the boards and up through every gap and the skirting. It is why a room can feel cold at ankle height while the thermostat reads 21°C. Floor insulation fixes this properly; foam strip under the skirting is the quick version.
- Loft hatches. An unsealed hatch is a chimney into the loft, and it undoes part of the loft insulation you already paid for.
- Open chimneys. A fireplace that is never lit still draws air 24 hours a day.
- Behind kitchen units, under baths and round downlights. Pipes, flues, cables and light fittings are holes through to the outside or the loft, and are rarely sealed.
Our free heat loss survey finds these. In the heating season we use a thermal camera, which shows an air leak as a cold streak on the inside surface; see what a thermal imaging survey shows.
What must you not seal?
Draught proofing goes wrong when it is confused with sealing the house. A home needs a controlled supply of fresh air to take moisture out. Seal the wrong thing and you swap a cold room for a damp one.
- Trickle vents in window frames. They are the designed background ventilation for the room. Leave them open, especially in bedrooms.
- Extractor fans in kitchens and bathrooms. Check they work; a dead fan is a common find.
- Air bricks to a suspended floor void. Blocking them is how joists rot. If the floor is draughty, insulate it and seal the boards, not the bricks.
- Ventilation for an open flue appliance. A gas fire, open fire, stove or older open flue boiler needs a permanent air supply by law. Do not seal a vent in that room unless a Gas Safe engineer has confirmed it is not needed.
Can I do it myself?
Yes, for the simple items. Self-adhesive foam strip, a letterbox brush and a chimney balloon are all available from any DIY shop for less than the fitted prices above, and a careful afternoon will cover most of a modern house.
Where a professional earns their fee is on old timber windows and doors. Sash windows need the right seal in the right place (parting bead, staff bead, meeting rail) or the window sticks; casements that have dropped need easing before any seal will close the gap; front doors often need a new threshold rather than another strip. Our own team fits draught proofing as its own visit or as a line on our floor and internal wall insulation quotes, because the gaps are exposed while we are there.
VAT, and what to do next
Draught stripping for doors and windows is listed as an energy-saving material in HMRC VAT Notice 708/6, so a professional install is 0% VAT until 31 March 2027, after which the rate is due to become 5%. Our guide to 0% VAT on energy-saving materials covers what qualifies.
- Book the free heat loss survey. We check every door, window, hatch, flue and floor void and list the gaps in order of size.
- You get a written plan with draught proofing priced as its own line, next to the bigger measures, so you can see what pays back fastest.
- Fit it first or with the first insulation measure. It never needs to wait for scaffold, planning or a dry spell.
The draught proofing service page has the method detail and the whole house package. For how draughts compare with walls, roof and floor, see where homes lose heat.
Frequently asked questions
How much does it cost to draught proof a whole house?
Typically £250 to £700 for a professional fit covering every external door and window, the loft hatch, letterbox and the obvious gaps round pipes and skirting. A Victorian house with sash windows sits at the top of the range; a modern house with uPVC windows at the bottom.
How much does draught proofing save per year?
It depends on how draughty the home was. As an indicative figure, a whole house package saves around £60 to £150 a year on heating, with single items such as a letterbox brush or loft hatch seal saving £10 to £30 each. The comfort improvement is immediate and often the bigger benefit.
Should I seal my trickle vents to stop draughts?
No. Trickle vents are the designed background ventilation for the room and closing them leads to condensation and mould. Seal gaps you do not need (doors, hatches, pipes); leave open the ventilation you do (trickle vents, extractor fans, air bricks, flue vents).
Can I block up an unused chimney?
Yes, with a chimney balloon from inside or a cap on the pot, at £60 to £250. Either needs to leave a little ventilation so the flue does not get damp, and a balloon must come out before the fire is ever lit.
Is there VAT on draught proofing?
Not at present. Draught stripping is an energy-saving material under HMRC VAT Notice 708/6, so a professional install is 0% VAT until 31 March 2027, then 5%. Materials bought for DIY carry the normal 20%.