How to Draught-Proof a UK Home

Draught proofing is one of the quickest ways to make a UK home feel warmer. The aim is to seal unwanted gaps around windows, external doors, floors, loft hatches and service penetrations while leaving intentional ventilation working. Done carefully, it can improve comfort and reduce heat loss without a major renovation.

Start by finding the actual source of each draught. Repair loose windows and doors before adding seals, use materials suited to the movement and construction of the gap, and test every opening afterwards. Never block trickle vents, airbricks, extractor fans or ventilation required by a boiler, fire or other combustion appliance.

What draught proofing can and cannot fix

A draught is uncontrolled air movement through a gap in the building. Common examples include a poorly fitting casement window, a gap below an external door or an unsealed loft hatch. Draught proofing closes these local gaps so that heated air escapes more slowly and cold air is less noticeable.

It is not a substitute for insulation, ventilation or building repair. A cold wall may need insulation rather than a tube of sealant. A wet patch, rotten frame, badly cracked wall or persistently sticking window needs its cause investigated before it is covered. The Energy Saving Trust’s draught-proofing guidance also notes that insulation generally makes a greater overall difference to heat loss, although draught proofing is often cheaper and easier to start with.

Find the draughts before buying materials

Survey the home on a cold or windy day, with external doors and windows closed. Work through one room at a time and record the location, size and likely cause of every gap. Useful signs include:

• daylight showing around a closed window or door;
• rattling frames, whistling or moving curtains;
• a noticeable stream of cold air felt with the back of a hand;
• a lightweight tissue moving near a suspected gap;
• dust lines around a loft hatch, floorboard or skirting board; and
• worn, flattened, missing or painted-over seals.

Do not use a candle, match or other naked flame to look for air movement. It creates a fire risk and is particularly unsafe near curtains, gas appliances or an unknown leak. A thermal camera can help identify cold areas, but it does not by itself prove that a draught is present.

What you find	Likely response
A narrow moving gap around an opening window	Fit a correctly sized compression or brush seal
A fixed crack between a frame and wall	Repair the cause, then use a compatible flexible sealant
A loose hinge, latch or distorted frame	Repair or adjust it before adding a seal
A trickle vent, airbrick or extractor grille	Leave it open, clear and working
A large crack, damp patch or decayed timber	Investigate the building defect rather than covering it

Know which openings must stay open

Homes need controlled ventilation to remove moisture, pollutants and stale air. Over-sealing can increase condensation and contribute to damp and mould. The UK Government’s damp and mould guidance identifies inadequate ventilation as one factor that can allow moisture problems to develop.

Do not seal or cover:

• Trickle vents: these are designed to provide background ventilation and should normally remain open.
• Extractor fans and grilles: keep kitchen and bathroom extract systems clean and operational.
• Airbricks and underfloor vents: they may protect suspended timber floors and other parts of the building from moisture.
• Wall vents: establish their purpose before changing them.
• Combustion-air openings: gas, oil, solid-fuel and other combustion appliances may need permanent ventilation. Ask a competent engineer if uncertain.
• Chimneys or flues in use: never obstruct the route that carries combustion gases out of the home.

Internal door gaps can form part of the home’s planned airflow, so they should not normally receive permanent seals. A removable draught excluder beside a cold, unused room may improve comfort, but only where it will not interfere with ventilation, a fire door or the safe operation of an appliance.

How to draught-proof windows

First clean the frame and check that hinges, catches and handles pull the opening section evenly against it. A failed hinge or distorted frame cannot usually be corrected by adding a thicker strip. Repair the hardware or timber first.

Casement and other hinged windows

Fit self-adhesive foam, rubber or silicone compression strip to the part of the frame against which the opening casement closes. Follow the product instructions and keep drainage holes, hinges, locking points and trickle vents clear. The strip should compress enough to stop the gap without making the handle difficult to close.

Measure the gap at several points because older frames are rarely uniform. If the strip is too thin, it will not seal. If it is too thick, the window may not latch or the hardware may be strained. Test the complete opening and emergency escape function after fitting.

Sash windows

Sliding sash windows need brush seals that allow the sashes to move. Foam strip between sliding surfaces can bind, peel away or prevent the window working correctly. A specialist can route discreet brush seals into the meeting rails, staff beads and parting beads while repairing cords, weights and loose joints.

For historic windows, repair is usually preferable to replacement. Historic England’s guidance on modifying historic windows describes draught proofing as a low-cost measure with substantial potential benefit, but invasive work can affect a listed building’s special interest. Seek advice before cutting grooves or altering significant fabric.

Fixed gaps and temporary measures

A small fixed gap between a sound window frame and the surrounding wall may be suitable for a flexible, compatible sealant. Do not seal over decay, movement or water entry. Heavy curtains, lined blinds or interior shutters can reduce the sensation of cold near glass, but keep curtains away from heaters and do not cover a radiator or block a trickle vent.

How to draught-proof external doors

Close the door and inspect all four sides. Tighten or repair loose hinges and adjust the latch so the door closes securely without being forced. Then use the smallest appropriate measure for each gap:

• Sides and top: fit a compression strip to the frame where the door closes against it.
• Bottom edge: fit a brush, wiper or hinged flap suited to the threshold and floor finish. Make sure it does not catch or create a trip hazard.
• Letterbox: use a purpose-made flap or brush seal that still allows post to pass and the flap to close.
• Keyhole: fit a simple escutcheon or keyhole cover where compatible with the lock.
• Unused external door: a removable fabric excluder can supplement a proper seal, but it should not obstruct an escape route.

Open and close the door repeatedly after fitting. It must still latch, lock and release normally. Do not create a seal so tight that someone has to pull hard on the handle or slam the door.

Flat entrance doors and fire doors

A flat entrance door may be a fire-resisting doorset. Do not drill it, plane it, replace its seals, change the letterbox or add hardware without approval from the landlord, freeholder or building manager and advice from a competent fire-door specialist. London Fire Brigade’s fire-door advice says residents should not alter or repair fire doors themselves. Report gaps, damaged seals or a door that does not close firmly.

Seal floors, skirting boards and loft hatches

Gaps between floorboards and along skirting boards can produce noticeable low-level draughts, particularly above a suspended timber floor. Use a flexible filler made for moving timber joints rather than a rigid product that will crack. For larger or irregular floorboard gaps, purpose-made flexible strips can be pressed between sound boards. A rug adds comfort but does not repair the air path.

Do not block external airbricks or the ventilated void beneath a suspended floor. If floorboards are damp, soft or moving excessively, investigate moisture, ventilation and structural condition before filling gaps.

A loft hatch can often be treated like a small door. Fit a suitable compression strip around the clean hatch frame so it closes evenly. The hatch should remain easy to open, and any insulation above it should not prevent secure closure. Large loft gaps, missing fire protection or poorly fitted recessed lights need more than a surface seal.

Treat gaps around pipes and cables carefully

Small gaps where water pipes or cables pass through an ordinary internal surface may be suitable for a compatible flexible sealant. Larger openings may need a backing material or a specified fire-stopping system rather than general expanding foam.

Do not apply ordinary filler or foam around a boiler flue, chimney, stove pipe, electrical fitting, gas meter or any opening that may form part of a fire-resisting wall or floor. Heat, access, ventilation and fire-stopping requirements differ. Use a competent installer where the purpose or construction of the opening is uncertain.

Reduce draughts from an unused chimney

An open chimney can draw warm room air out of the home even when no fire is lit. If the fireplace is genuinely unused, consider a purpose-made removable chimney draught excluder or a professionally fitted ventilated cap. The chimney should not be sealed completely because some ventilation helps manage moisture.

Choose an excluder with a visible reminder and remove it before lighting any fire. Do not fit one where an appliance uses the chimney or where there is any chance that combustion gases could be obstructed. Have the flue and fireplace assessed if their status is unclear.

Take extra care in traditional and listed buildings

Older buildings often manage moisture differently from modern homes. Breathable construction, timber movement, open flues and traditional windows need compatible materials and a whole-building approach. Cadw’s guidance for historic buildings in Wales supports draught proofing as a cost-effective measure while stressing the need to preserve ventilation and avoid unintended moisture problems.

Use repairable and reversible measures where possible. Retain sound historic windows and doors, repair failed joints, and obtain specialist advice before altering significant fabric. Listed building consent, planning permission or other approval may be needed for some work, and rules vary across the UK. Contact the relevant local planning authority or conservation service before making an uncertain alteration.

Draught proofing in a rented home

Report defective windows, external doors, damp, decay and missing ventilation to the landlord or agent. A loose frame or water leak is a repair issue, not simply a draught-proofing task. Obtain written permission before applying permanent adhesive products, drilling, filling gaps or altering doors and windows.

Removable fabric door excluders, curtains and some non-damaging temporary measures may be practical while permission is considered. Never alter a fire door, cover a vent or interfere with a boiler or other appliance, even temporarily.

How much can draught proofing save?

Energy Saving Trust estimates published in May 2026 put professional whole-house draught proofing of windows and doors at about £250. Its modelled annual saving for draught proofing windows, floors and doors is around £55 in Great Britain and £80 in Northern Ireland. Draught proofing an unused open chimney is estimated to save around £45 a year in Great Britain and £60 in Northern Ireland.

These are illustrative estimates, not guaranteed quotes or savings. The result depends on the property, existing gaps, heating system, fuel price, occupancy and quality of installation. DIY work may cost less, while sash windows, heritage fabric, access problems and building repairs can make professional work more expensive.

Prioritise the gaps that produce obvious air movement, then improve the building in a sensible order. Draught proofing works best alongside suitable insulation, a well-controlled heating system and effective ventilation. Property owners in England and Wales can use the GOV.UK home energy service for personalised improvement suggestions. Separate official services are available in Scotland and Northern Ireland.

When to use a professional

Basic seals on sound modern doors and windows are often suitable for careful DIY work. Get professional advice when the job involves:

• sash windows, valuable joinery or historic building fabric;
• a listed building or property in a conservation area;
• a flat entrance door or any identified fire door;
• a chimney, flue, boiler, stove or permanent appliance ventilation;
• large cracks, rotten timber, damp or structural movement;
• fire stopping around pipes, cables or service risers; or
• windows and doors that no longer close or lock safely.

Ask what materials and preparation the quote includes, whether the installer will repair or merely cover defects, and how ventilation will be protected. Compare several written quotes where practical. TrustMark’s homeowner service can be used to find businesses registered with the UK Government Endorsed Quality Scheme.

Test the work and check it regularly

After fitting each seal, open and close the window or door several times. Confirm that locks, handles, latches and escape openings work normally. Check that all trickle vents, airbricks and extract systems remain clear and that no appliance ventilation has been disturbed.

Look again after the first period of cold or wet weather. Replace strips that have peeled, torn or compressed, and watch for new condensation or mould. More moisture on windows, stale air or slower bathroom drying can indicate that ventilation needs attention. Review seals each autumn and after decorating, because paint can obstruct vents and moving parts.

UK home draught-proofing checklist

• Survey one room at a time on a cold or windy day.
• Separate unwanted gaps from intentional ventilation.
• Repair loose hardware, decay, leaks and large cracks before sealing.
• Use compression strips for suitable hinged windows and brush seals for sliding sashes.
• Seal the top, sides, letterbox and threshold of ordinary external doors where appropriate.
• Do not alter a flat entrance fire door without competent approval.
• Use flexible products for moving floorboard and skirting gaps.
• Keep airbricks, trickle vents, extractors and combustion ventilation open.
• Use a removable, clearly marked chimney excluder only in a genuinely unused fireplace.
• Get specialist advice for historic fabric, flues, fire stopping, damp and structural defects.
• Test every door and window after fitting and review seals each autumn.

Home draught-proofing resources

• Energy Saving Trust draught-proofing guidance covers common gaps, suitable products, ventilation and current indicative costs and savings.
• GOV.UK home energy service provides personalised improvement suggestions for property owners in England and Wales and directs users to the relevant services elsewhere in the UK.
• Home Energy Scotland winter preparation guidance includes practical measures for reducing draughts and retaining heat.
• TrustMark homeowner guidance explains the UK Government Endorsed Quality Scheme and provides a registered-business search.
• Historic England guidance on historic windows covers repair, draught proofing, significance and consent considerations in England.
• Cadw guidance on energy efficiency in historic buildings explains the whole-building approach for traditional and historic properties in Wales.
• London Fire Brigade fire-door guidance explains what residents should check and why fire doors should not be altered or repaired without suitable expertise.
• UK Government guidance on damp and mould explains the health risks and the importance of addressing moisture, ventilation and building defects.