Draught proofing windows cost: three different bills

A cold casement and a £4.49 coil are not the same decision as a fitter's visit. The draught proofing windows cost people quote at you is usually one of three bills. The Energy Saving Trust puts professional draught-proofing of windows and doors at around £250 for a whole house, and says DIY is cheaper. On amazon.co.uk on 15 October 2026, nine kept coils ran from £4.49 to £20.18 a pack. The Trust's about £55 a year in Great Britain is windows, floors and doors together, not the payback on one roll.

Products Compared read those listings and the public UK pages named below on 15 October 2026. We did not laboratory-test the coils. A qualifying purchase through an Amazon link can earn us a commission at no extra cost to you.

In short

Professional draught-proofing of windows and doors is about £250 for a whole house, and a self-adhesive coil is a few pounds. Those are different jobs. The about £55 a year in Great Britain, and about £80 in Northern Ireland, covers windows, floors and doors together. It is not the saving on one window.

Three bills that are not the same job

A pack buys a length of seal, not a day's labour. The cheapest kept foam that day was £4.49 and the dearest kept coil, a push-in gasket, was £20.18. A 6 m roll might finish one large door or several small casements. It is not a price per window until you measure the perimeter.

The £250 line is national guidance for windows and doors together, not a quotation for your postcode. If a fitter's email covers only two leaking sashes, you have left that scope. Ask what is included before you treat the guidance number as wrong.

Checkatrade's guide, excluding VAT, puts strips or sealant at about £50 a window and about £100 a door, and says sash windows cost significantly more. VAT can lift the invoice above those lines. That table does not replace the Trust's £250 figure. A £4.49 coil and a £50 visit are not the same afternoon. Do not add a coil to £250 and divide by the number of windows. The window seal comparison holds the pack prices. It is not a fitter's quote.

What the Energy Saving Trust priced

The £55 and £80 figures include floors. A coil on one casement is not that saving. A second Trust note, on older homes, leaves floors out: windows and doors of a typical gas-heated semi in England, Scotland or Wales might save around £30 a year. Checkatrade restates around £85 a year in Great Britain, which does not match the £55 on the Trust page used here. This article does not average them.

Wrexham's 2024 bulletin repeats roughly £80 and roughly £250 from an older framing. When public numbers disagree, label the page and the rooms, then stop. Do not invent a pounds-saved figure for one listing. Foam may not last long. The Trust says brush or wiper strips last longer and cost more, and no year-count or brush price is stated here.

The Trust's DIY page puts strips at around £2 a metre. Several coils below are cheaper per metre, while a brush seal for a sash can cost more. Foam is a poor fit on sliding sashes. The Centre for Sustainable Energy points brush seals at sashes and asks for a short test piece first. A sash that is loose in the frame needs a joiner, not a thicker roll of foam.

What a DIY coil costs on amazon.co.uk

These nine kept listings are not every roll in Britain. YANKUIRUI was £4.49 for 6 m, sold as two 3 m pieces, with a stated gap of 3–6 mm and 4.4 stars from 2,938 ratings. It is the top pick for a stick-on rebate where that gap is real, not for a perished gasket in a groove. "EPDM" on that page is a material line, not a certificate. UPSEN was £4.99 for 10 m, about 50p a metre, stated at about 3.5–5 mm, with 4.3 stars from 3,025 ratings. Inside that band it is the best value, because YANKUIRUI is about 75p a metre.

Bynsaer was also £4.49, stated at 3–5 mm, but one reviewer measured about 3 m before the roll was split, so there is no clean price per metre. GUKOY was £6.99 for 20 m of flat tape, about 35p a metre, with no stated gap, so that metre price is not a D-profile. Tarqite was £7.89, with 4.5 stars from nine reviews, which is too few for a proven top pick, no stated gap, and fields that say 6 m, 8 m and 80 cm. Esufeir was £7.99 for a rubber D stated at 2.5–6 mm, with 6 m in the title and 1.0 metre in the unit count. wordmouk was £8.98 for face tape and WanderGo was £9.99 with no stated gap. A higher pack price does not buy a clearer gap.

Storm Patrol was £20.18 for 25 m, about 81p a metre, with 4.5 stars from 306 ratings. It states frames of 3–5 mm, is described as made in the United Kingdom, and publishes no foot width. Per metre it sits close to YANKUIRUI, so the higher pack price is mostly the length. Try a short sample only if a groove remains. If the foot will not enter the slot, it is the wrong fixing. See foam window seal or gasket and best window seals. None of the nine shows a BS EN 12365 class. A draught seal is not a lock or a PAS 24 test of the window.

When a thicker strip stops the lock

A strip that is too tall can stop the sash meeting the frame, so the lock will not engage. Seals Direct's rule of thumb for a bubble is a section about a third higher than the gap, and you still have to try it. The Centre for Sustainable Energy's test is a piece about 50 mm long: fit the offcut, shut the handle, and stop if the window strains. The Energy Saving Trust says not to overfill the gap.

One Esufeir reviewer sealed a whole back door, found the lock too tight, and cut the strip back. A GUKOY reviewer could not close doors that already fitted closely. A Storm Patrol reviewer found the bubble a little thicker, and a door stayed stiff until the rubber settled. The £4.49 foam can do the same if a 9 mm by 6 mm D-profile lands on a gap that was already closing.

Measure the coil on arrival. If you bought against a 6 m description and the parcel is far shorter, sections 9 to 11 of the Consumer Rights Act 2015 treat the description as part of the contract. That does not refund a strip that was the stated size and still too fat. Fitting order, including a clean dry rebate, is on how to fit a window seal. Stop when the lock tells you to peel the strip off.

Vents and the saving you must not claim

Do not tape a trickle vent shut. The Energy Saving Trust says not to seal trickle vents, grilles or wall vents, and that extra draught-proofing in a home that is already tight can hurt air quality. The Centre for Sustainable Energy says to leave flues and trickle vents open. Air bricks, extractors and combustion-air openings stay open for the same reason. Do not draught-proof internal doors to chase the £55 figure.

Approved Document F is the ventilation background for replacement windows in England. Draught-proofing on its own might not count as building work, and you should not shrink the background ventilators on a replacement window. If the only draught is the vent, seal the sash gap, not the ventilator. Measure that gap on the window seal buying guide. About £55, about £80, about £30 and about £85 are not the saving on one coil. These figures are the 15 October 2026 shelf, and they will drift. Foam has no year-life stated here.