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Draught-proofing on a budget: fixes under £20
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A lot of winter heat leaves through gaps you can feel with your hand: under an external door, around a letterbox, through a keyhole, around an opening window, or up an unused chimney. The Energy Saving Trust says these are straightforward DIY jobs if you are confident with simple tools, and the materials are cheap. They will not replace proper insulation, but they can make a room more comfortable and cut the heating you need.
If you also want to spend less on warming one person, see heated throws, blankets and gilets. To find out whether a heater or an always-on gadget is the expensive thing in the room, use an energy-monitoring smart plug.
What the Energy Saving Trust says you might save
On the Trust's draught-proofing page, checked today, 15 November 2026:
- Draught-proofing around windows, floors and doors could save around £55 a year in Great Britain (£80 in Northern Ireland).
- Draught-proofing an unused open chimney could save around £45 a year in Great Britain (£60 in Northern Ireland).
- Professional draught-proofing of windows and doors could cost around £250 for a whole house. DIY is cheaper.
Those figures are for the job as a whole, not for a single £8 door brush. Treat them as a guide. If an unused open chimney really is losing that much, a £19 chimney balloon has a rough payback of around one heating season; your house may be different. The Trust also notes that a draught-free home can feel comfortable at a slightly lower thermostat setting. Full guidance: Energy Saving Trust, Draught proofing.
What you should not block
The Trust is clear that ventilation still matters. Do not block extractor fans, underfloor grilles or airbricks, wall vents, or trickle vents. Rooms with open fires or open flues need enough air. If you have a flueless or open-flue gas appliance, do not cover its fixed ventilation openings. Internal doors should not be draught-proofed, because a gap under them helps air move through the house. Only seal the gaps that let cold air in from outside.
Never put a chimney balloon or other excluder in a flue that serves a gas fire, boiler, stove or any working appliance. Take a removable excluder out before you light a fire, and leave a reminder in the grate. A chimney should not be sealed completely airtight, because a little airflow helps keep it dry.
Fixes under £20 we checked today
Measure first, especially letterboxes and door widths. All of the items below were in stock on Amazon UK on 15 November 2026, at the prices shown. The Stormguard foam tape had only one left when we looked, so check stock. A well-known curtain lining we opened, the Emma Barclay thermal blackout lining pair, was £21.49, so it sits just over this budget and is not listed as a pick.
Amazon UK
Stormguard bottom-of-door brush seal, white, 914mm
£7.89
A brush strip for the bottom of an external door, in a 914mm (3ft) length. Measure your door and the gap to the floor before you buy; Stormguard also lists other lengths, including an 838mm gold version we saw at £8.59. Cut or fit it so the brush just touches the floor and the door still opens easily. This is for an outside door, not an internal one.
Price checked 15 November 2026
Amazon UK
Stormguard internal letterbox brush cover, white
£5.99
A simple internal letterbox brush, with external dimensions of 335mm listed on the page. The Energy Saving Trust says a letterbox brush or flap is the right fix, and that you should measure the letterbox first. This was the cheapest branded letterbox option we verified today. A Chimney Sheep interior brush seal at £14.00 was also in stock if you want a different style.
Price checked 15 November 2026
Amazon UK
Cyclaire keyhole draught excluder, pack of 2
£5.99
Two sliding keyhole covers that stick on and drop a cover over the hole, which is the sort of purpose-made cover the Energy Saving Trust describes. Slide it up to use the key. Check the size (the listing gives an overall size of 37 × 27mm and a slot of 24 × 8mm) against your escutcheon, especially on uPVC doors, where some buyers find a poorer fit.
Price checked 15 November 2026
Amazon UK
Stormguard Ultraseal self-adhesive foam draught excluder, 5m, white
£4.49
A 5-metre foam strip for the small gap between an opening window, or an external door, and its frame. Foam is the cheap, easy option the Energy Saving Trust mentions; it may not last as long as a brush or wiper strip, and it does not suit sliding sash windows. Only one was left in stock when we checked, so look at the page before you rely on this price.
Price checked 15 November 2026
Amazon UK
Chimney Balloon, medium, 14 × 24 inch
£19.00
An inflatable, removable chimney draught excluder, made in the UK, with a mouth tube. Measure the flue opening first and pick the right size. It must come out before anyone lights a fire; the maker includes a reminder card for the grate. Use it only in an unused chimney, never in a flue that serves an appliance, and do not seal the chimney completely airtight. At £19, it is the one item here that can sit close to the Trust's around £45 a year chimney figure, if that estimate applies to your fireplace.
Price checked 15 November 2026
Amazon UK
Stormguard radiator reflective foil, 4m × 47cm
£11.49
A 4-metre roll of foil-faced foam to sit behind a radiator on an external wall, so more of the heat comes into the room instead of warming the wall. Cut it to the radiator width and follow the fitting instructions. We have not seen a separate Energy Saving Trust saving just for radiator foil, so we have not invented a payback figure for this one.
Price checked 15 November 2026
Amazon UK
Pair of eyelet thermal blackout curtains
£16.99
A pair of lined, insulated eyelet curtains that was £16.99 for the size selected on the page we opened. Curtain prices change a lot with width and drop, so check the exact size against your window, and check whether the £16.99 still applies to that size at checkout. A dedicated Emma Barclay thermal lining pair in 66 × 72 inch was £21.49, just over this under-£20 list.
Price checked 15 November 2026
A simple order to work in
- Walk the house on a windy day and feel for air at external doors, letterboxes, keyholes, opening windows and unused fireplaces. If you can see daylight under a door, start there.
- Fit the door brush, letterbox brush and keyhole cover on external doors. Measure twice.
- Add foam or brush strips to opening windows, without covering trickle vents.
- If you have an unused open chimney, measure the flue and fit a removable excluder, with a reminder not to light a fire until it is out.
- Radiator foil is a tidy extra on external walls, once the obvious draughts are stopped.
If your windows or doors are in poor condition, or the house is old and needs breathable materials, the Trust suggests professional help. Search for a TrustMark installer if you go down that route.
All prices were read from Amazon UK's own product page on 15 November 2026. Prices can change, stock can run out, and delivery charges may apply. Amazon links include our Associates tag. Energy Saving Trust figures are its published estimates, checked on the same day, and are not a personal saving. This is not a recommendation to buy any particular product, and it is not safety advice: do not block required ventilation or a working flue.
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