How to draught-proof windows and doors

2 min read · 8 steps · Updated 3 October 2026

A draught is cold air coming in and warm air going out through gaps that were never meant to be there. Closing them is among the cheapest ways to make a home warmer, costs little in materials, and most of it can be done in an afternoon. The advice below follows the UK's Energy Saving Trust.

If you rent, ask your landlord before you change anything fixed to windows, doors or walls. Removable strips and seals are normally fine.

Step by step

1. Find the draughts

   On a cold, windy day, move the back of a damp hand along window and door frames, skirting boards, the loft hatch and pipes that pass through walls. Look for daylight around closed doors, and listen for rattling.

   Done

2. Windows that open

   Fit self-adhesive foam strips into the frame where the window closes against it. They are cheap and easy, and last a few years. Metal or plastic strips with brushes or wipers cost more and last longer. Measure the gap first: a strip that is too thick stops the window closing, and one that is too thin does nothing.

   Done

3. Sliding sash windows

   Foam does not work on sashes that slide. Use brush strips, or have them fitted by a specialist.

   Done

4. Windows that do not open

   Seal gaps between the frame and the wall, or around fixed panes, with silicone sealant.

   Done

5. Outside doors

   Fit a brush or hinged draught excluder along the bottom, and foam, brush or wiper strips around the edges. Add a cover with a metal disc over the keyhole and a brush or flap inside the letterbox.

   Done

6. Floors and skirting boards

   Fill gaps between floorboards and under skirting boards with a flexible filler, decorator's caulk or mastic, which moves with the wood. Do not use a rigid filler.

   Done

7. Loft hatch and unused chimney

   Put draught strips around the loft hatch as you would a door. An open fireplace that is not used can be closed with a removable chimney draught excluder. Take it out before you ever light a fire.

   Done

8. Leave the ventilation alone

   Do not block extractor fans, wall vents, airbricks and underfloor grilles, trickle vents in window frames, or the air supply of a gas boiler, fire or stove. A home needs controlled ventilation to stay free of damp and safe.

   Done

Good to know

Do not draught-proof the doors between rooms inside the home. Air has to be able to move between them.

Kitchens and bathrooms need their ventilation most. After draught-proofing, keep airing in short bursts: condensation on windows: how to stop it and prevent mould.

Thick curtains closed at dusk, and a rolled blanket along the bottom of a door, cost nothing and help at once.

The Energy Saving Trust puts the saving from draught-proofing windows, doors and floors in a typical British home at roughly 55 pounds a year, more if you can then turn the thermostat down by a degree.

Related: how to lower your energy bill, how to bleed a radiator and carbon monoxide at home.

In short: Find gaps with a damp hand, foam or brush strips on opening windows, silicone on fixed frames, brush strip, keyhole and letterbox covers on outside doors, flexible filler for floors. Never block vents.