How to find and fix draughts around windows, doors, floors, chimneys and loft hatches, the materials to use, what not to block, typical costs and when to call a professional.
Draught-proofing is one of the cheapest and most effective ways to make a home warmer and cut heating bills. Most jobs are simple DIY with inexpensive materials. The key is sealing unwanted gaps while keeping the ventilation your home needs.
Step 1: find the draughts
- On a windy day, hold the back of your hand near windows, doors, skirting boards and hatches to feel moving air.
- Watch a candle or incense stick flicker near suspected gaps (carefully, away from curtains).
- Look for daylight around closed doors and for dust marks on carpets at skirting boards.
Common culprits: windows and doors, letterboxes and keyholes, loft hatches, floorboards and skirting, unused chimneys, and gaps around pipes and cables.
Step 2: windows
- Self-adhesive foam strips: cheap and easy for opening windows, but wear out in a few years.
- Rubber (EPDM) or silicone strips: more durable and better for larger gaps.
- Brush strips: best for sash windows, which slide.
- Silicone sealant: for gaps between frames and walls that never open.
Clean and dry the frame before fitting, and check the window still closes properly.
Step 3: doors
- Fit a brush or hinged-flap draught excluder to the bottom of external doors.
- Use foam or rubber strips around the frame.
- Fit a letterbox brush or flap, and a keyhole cover.
- A fabric draught excluder works for internal doors to unheated rooms.
Step 4: floors and skirting
Gaps between floorboards and under skirting boards can be filled with flexible filler, silicone or purpose-made strips. Rugs help too. Don't block airbricks in external walls: they ventilate the space under suspended timber floors and prevent rot.
Step 5: loft hatches
Fit foam strips around the edge of the hatch and insulate its top so warm air doesn't escape into the loft.
Step 6: chimneys
An unused open chimney can let a lot of heat escape. Use a removable chimney balloon or a cap fitted by a professional. Leave some ventilation to prevent damp, and always remove any blocker before lighting a fire.
Step 7: pipes and cables
Fill gaps where pipes and cables pass through walls with silicone or expanding foam (for larger gaps).
What not to block?
- trickle vents in windows;
- extractor fans and airbricks;
- wall vents for rooms with fuel-burning appliances such as gas fires, open-flue boilers or wood burners. These need air to burn safely, and blocking them can cause carbon monoxide build-up;
- ventilation in kitchens and bathrooms, which helps prevent condensation and mould.
Fit a carbon monoxide alarm in rooms with fuel-burning appliances.
Costs and savings
Basic materials for a typical home cost tens of pounds. The Energy Saving Trust estimates that draught-proofing an average home can cut heating bills every year, and rooms feel warmer at a lower thermostat setting. Its website has current estimates for each type of home.
When to get a professional?
- sash windows needing full draught-proofing systems;
- chimneys and anything involving fuel-burning appliances;
- listed buildings, where changes may need consent;
- large gaps that suggest rot or structural problems.
Check for local grants and energy efficiency schemes, which may help with costs for eligible households.
Priority order
- External doors and the letterbox.
- Windows in the rooms you heat most.
- Loft hatch.
- Unused chimney.
- Floors and skirting.
Renting?
Simple removable measures, such as foam strips and door excluders, are usually fine. Ask your landlord before making permanent changes.
Frequently asked questions
Can draught-proofing cause damp?
It can if you block necessary ventilation. Keep vents clear and ventilate kitchens and bathrooms.
How long does it last?
Foam strips a few years; rubber and brush strips much longer.
Sources and further reading
Facts checked on 20 October 2026. Spotted an error? Tell us and we will correct it.