Draught-proofing your home

Most homes have a cold spot or two in winter. Often the cause is a small gap that lets outside air in.

Sealing those gaps is one of the simplest ways to keep a home warmer. It needs a little care, because every home still needs fresh air.

Finding the draughts

Light showing under or around a door or window is a good clue. So are rattles and whistling on a windy day, and curtains that move when the window is shut.

The Energy Saving Trust suggests feeling for moving air in a few likely places.

Around doors and windows.
Along floorboards and skirting boards.
Where pipes pass through an outside wall.
On stairways and around fireplaces.

Doors and windows

Windows that open can take draught strips around the frame. Self-adhesive foam strips are cheap and easy to fit, though they may not last long. Strips with brushes or wipers last longer. The strip needs to fit the gap, so the window still closes. Sash windows suit brush strips, and windows that never open can be sealed with silicone.

An outside door has four places to look at. A keyhole cover drops a small metal disc over the keyhole. A flap or brush closes off the letterbox. A brush or hinged excluder fills the gap at the bottom, and strips seal the edges. Leave a gap under inside doors, so air can move around the house.

Floors, lofts and chimneys

Gaps between floorboards and skirting boards can be filled with a flexible filler, such as decorator's caulk. Floors move a little with everyday use, so the Energy Saving Trust suggests a filler that can cope with movement. A loft hatch can take the same strips as a door. Small gaps around pipes take silicone, and larger ones take expanding foam.

An unused chimney lets warm air go up and cold draughts come in. A cap over the chimney pot is one answer. A chimney draught excluder is another, and it should leave some air flowing. Take it out before you light a fire.

The air a home still needs

Fresh air keeps a home dry and healthy, especially in kitchens and bathrooms. The Energy Saving Trust asks people to keep these open.

Extractor fans.
Airbricks and underfloor grilles, which keep wooden floors dry.
Wall vents.
Trickle vents above windows, which are normally left open all the time.

Rooms with an open fire, a flue or a gas appliance need their air supply. Fixed vents for a gas fire or heater must stay clear. The Health and Safety Executive advises having a gas appliance checked after draught-proofing the room it is in.

Carbon monoxide has no colour and no smell. The NHS suggests a carbon monoxide alarm in each room with an appliance that burns gas, oil, coal or wood.

Doing it yourself or getting help

Someone confident with simple DIY can usually draught-proof a home. Older homes with traditional features can be harder, and a professional will know the right materials. The Energy Saving Trust suggests getting three quotes. TrustMark, the government-endorsed quality scheme, lists certified installers. In Scotland, Home Energy Scotland gives free advice on keeping warm at home.

A home with no trickle vents, wall vents or mechanical ventilation may already be quite airtight. In that case, the Energy Saving Trust says draught-proofing may not suit it.

What it can save

The Energy Saving Trust's guide, last updated in May 2026, gives an estimate. Draught-proofing windows, floors and doors could save around £55 a year in Great Britain and £80 in Northern Ireland. Blocking an unused chimney could save around £45 a year in Great Britain and £60 in Northern Ireland.

A home without draughts also feels comfortable at a lower temperature, so people can often turn the thermostat down. The NHS suggests keeping the rooms you use most at 18°C or more, if you can.