The short answer
We read 30 of the best-selling draught excluders on Amazon UK on 7 September 2026. Twenty-three are sold on keeping heat in. Eight say what size gap they actually seal. A basket of the ones that do say costs £28.76 and covers two external doors and the frames of a small house.
Draught proofing is the cheapest thing you can do to a cold house. The Energy Saving Trust puts the saving at around £55 a year in Great Britain for draught proofing windows, floors and doors, and around £250 to have it done professionally. At those numbers almost anything you buy pays for itself.
The problem is not the price. It is that most of these products do not tell you the one thing that decides whether they work.
The gap is the product
A draught excluder works by filling a gap. Fit foam that is thinner than the gap and the air still goes through. Fit foam that is thicker and the door stops shutting properly, so people peel it off in November. The gap the strip is built for is not a detail on the spec sheet. It is the product.
So we scored each of the 30 listings on one thing. Does the maker’s own copy say what size gap this seals. We read only the title, the feature bullets, the product overview, the technical specification and the product description, so retailer blurb and review text are excluded.
| Counted | n | of | share |
|---|---|---|---|
| Sold on energy, heat loss or insulation in the maker’s own copy | 23 | 30 | 77% |
| States the size of gap it seals | 8 | 30 | 27% |
| Sold on heat and does not state the gap | 17 | 23 | 74% |
| Puts any number on the benefit | 1 | 30 | 3% |
| States a saving in pounds | 0 | 30 | 0% |
Amazon UK, search for draught excluder sorted by popularity, first 30 distinct products, read 7 September 2026. All 30 returned usable text. Every count above was checked by hand, which changed two of them, see the method note at the end.
Seventeen of the 23 products sold on keeping your heat in never say what gap they fit. Call it the unmeasured seal. The claim that it saves heat is doing the work that a measurement should be doing.
The single listing that puts a number on it says “Reducing 30% Heat Loss”. There is no test behind that figure on the page, no statement of what it was measured against, and no source. One number with nothing under it is not better than no number.
The eight that do state a gap are specific and useful. Two Stormguard brush strips say they seal gaps up to 25mm. Foam and D-profile tapes give ranges of 2mm to 6mm, 2.5mm to 6mm, 3mm to 5mm and 3mm to 6mm. One under-door seal says it compresses to fill gaps up to 5cm. That is all anybody needs, and most of the shelf does not print it.
What it costs to do a house, using only the products that tell you
If you buy only from the eight that state a gap, here is a basket for a small house with two external doors and a set of internal frames to seal. Prices are the Amazon UK listing prices on 7 September 2026.
| Item | Gap it states | Qty | Price |
|---|---|---|---|
| Stormguard gold door brush strip | up to 25mm under the door | 2 | £12.98 |
| D profile weather stripping, 20m | 2mm to 6mm | 1 | £11.99 |
| Foam sealing strip, 6m | 3mm to 6mm | 1 | £3.79 |
| Basket | £28.76 |
Prices read 7 September 2026 and they move. We take no commission on this page and nothing here is an affiliate link.
Against the Energy Saving Trust’s £55 a year, £28.76 pays for itself in about six months. That comparison flatters the basket, because the Trust’s figure covers windows, floors and doors and this basket does doors and frames, so it is doing part of the job rather than all of it.
The honest version is the one that survives being wrong. Even if this basket delivers only a third of the Trust’s saving, it pays back inside a year and seven months, and it is 11.5% of the £250 the Trust quotes for having the work done for you. Draught proofing is one of the few things in a home where the arithmetic is not close.
How to measure your gap in a minute
- Under a door. Slide a coin under it. A 10p piece is about 2mm thick and a £1 coin about 3mm. If several stack in the gap, you need a brush strip rather than tape.
- Around a door or window frame. Close it on a strip of paper. If the paper pulls out with no resistance, there is a gap worth sealing.
- Choose the strip below your measurement rather than above it. Foam that is too thick stops the door latching, and a door you cannot shut gets the strip taken off within a week.
Draught proofing and condensation pull in opposite directions, so it is worth reading them together. Sealing a house tighter keeps the water vapour in as well as the heat, which is why our guide to stopping condensation on windows prices ventilation alongside everything else. Seal the gaps you did not choose, and keep the ventilation you did.
Chimneys are the other big one. The Trust puts draught proofing an unused chimney at around £45 a year on its own, which is most of the value of the whole rest of the job.
The catch
The Energy Saving Trust’s £55 is a national figure for a typical home, updated on its site on 20 May 2026. Your house is not typical. A modern flat with two external walls has less to gain than a draughty Victorian terrace, and the same £28.76 of tape does far more in the second than the first.
Sealing a house up has a limit, and it is not a money limit. Homes need air changes, and a house with no ventilation gets damp, then mouldy. Never block an air brick, a trickle vent, or a vent serving a fuel-burning appliance. If you have a gas fire, a boiler with an open flue or a stove, the vents around it are part of the safety of the appliance and not a draught.
What this page cannot tell you
- Whether any of these products work. We have not fitted them, we have not run an air leakage test, and we do not claim to have.
- How long the adhesive lasts. None of the 30 listings gives a figure for that either.
- What you personally would save. That depends on your house, not on the product.
- Whether the one “30% heat loss” claim is true. We recorded that it is unsupported, not that it is wrong.
- What the prices are today. They were read on 7 September 2026 and Amazon repricing is constant.
Method and sources
- Sample. The first 30 distinct products returned by the Amazon UK search for draught excluder sorted by popularity, read 7 September 2026. All 30 returned usable maker copy and none were dropped.
- What was read. Product title, feature bullets, product overview, technical specification, detail bullets and product description. Reviews, editorial blurb and Amazon-generated blocks were excluded.
- Hand checks that changed the numbers. A first automated pass scored 9 listings as stating a gap size. Reading each by hand cut it to 8, because one gives only its own dimensions of 6mm by 3mm and tells you to measure your own gap, which is not the same as stating the gap it seals. The same first pass scored zero listings as putting a number on the benefit. Reading every mention of a pound sign or a percentage by hand found one, “Reducing 30% Heat Loss”, which a rule looking for the word save had missed. Both corrections are in the direction that makes our own headline weaker, which is the point of doing them.
- Saving and cost figures. Energy Saving Trust draught proofing advice page, read 7 September 2026, page updated 20 May 2026.
- Prices. Amazon UK listing prices as displayed on 7 September 2026.
How we work is on our methodology page. For what running things costs at the current cap, see the running cost index, and for what changed on 1 October, the October 2026 price cap page. If new glazing is the bigger question, start with energy efficient windows.
Questions people ask
How much does draught proofing save?
The Energy Saving Trust puts it at around £55 a year in Great Britain for windows, floors and doors, and around £45 a year for draught proofing an unused chimney.
What size draught excluder do I need?
Measure the gap first, then pick a strip rated at or just below it. Foam thicker than the gap stops the door closing. Only 8 of the 30 best-selling listings we read state the gap they seal, so check before buying.
Is draught proofing worth it?
On the arithmetic, yes. A £28.76 basket of gap-rated products pays back in about six months against the Energy Saving Trust’s £55 a year, and inside a year and seven months even if it delivers only a third of that.
Can you draught proof a house too much?
Yes. Homes need air changes or they get damp and then mouldy, and vents serving a fuel-burning appliance are part of its safety. Seal the gaps you did not choose and leave the ventilation you did.