Draught-proofing a typical three-bedroom house costs £150–£300 in materials and saves £90–£150 a year on energy bills
Homeowners typically spend between £150 and £300 on materials to draught-proof a standard three-bedroom house, with annual energy savings of £90 to £150 based on a gas-heated semi-detached property. The payback period for DIY work is usually one to three years, while professional installation adds £200 to £400 in labour costs, extending the payback to three to seven years.
Larger or older properties may require £400 to £500 in materials due to multiple chimneys or sash windows that need specialist seals. The savings figures assume a gas-heated semi-detached home; electric heating or smaller flats will see lower annual savings. The Energy Saving Trust estimates that draught-proofing can reduce a typical home’s heating bill by around £90 per year for a semi-detached property (Energy Saving Trust, 2026).
Draught-proofing materials and their costs per room
Self-adhesive foam strips for windows cost £3 to £8 per 10-metre roll, suitable for sealing gaps around opening casements. Brush or hinged-flap draught excluders for letterboxes range from £8 to £15 per unit, and keyhole and door-plate covers cost £2 to £5 each. Chimney draught excluders, either inflatable or foam, cost £15 to £40 per chimney. Silicone sealant or acrylic caulk for gaps in skirting boards and floorboards costs £5 to £10 per tube (Energy Saving Trust product guide, 2026).
For a typical living room, window strips, a door brush, and a chimney balloon will cost approximately £25 to £55 in materials. A kitchen requires window strips, a letterbox excluder, and an extractor fan cover, totalling £15 to £30. Bedrooms need window strips, a door brush, and floorboard sealant, costing £10 to £20 per room. Bathrooms need window strips and an extractor fan cover, costing £10 to £18. Hallways need a door brush, keyhole cover, and letterbox excluder, totalling £12 to £22.
Quick numbers, draught-proofing savings by room and fitting type
| Room | Typical fittings | Material cost per room (£) | Annual saving per room (£) |
|---|---|---|---|
| Living room | Window strips, door brush, chimney balloon | 25–55 | 25–40 |
| Kitchen | Window strips, letterbox excluder, extractor fan cover | 15–30 | 15–25 |
| Bedroom | Window strips, door brush, floorboard seal | 10–20 | 15–25 |
| Bathroom | Window strips, extractor fan cover | 10–18 | 10–15 |
| Hallway | Door brush, keyhole cover, letterbox excluder | 12–22 | 10–20 |
Savings are based on the Energy Saving Trust draught-proofing calculator and Ofgem Typical Domestic Consumption Values for 2026 (Ofgem, 2026). Actual savings vary with house size, heating type, and how many gaps exist.
The direct answer, draught-proofing a house means sealing gaps around windows, doors, chimneys, floorboards, and pipework to stop uncontrolled airflow
Draught-proofing is the process of blocking unintentional gaps that let cold air in and warm air out. It does not include ventilation required for gas appliances or extractor fans, which must remain open or be fitted with trickle vents. Typical gaps include window frames, door edges, letterboxes, keyholes, under skirting boards, around pipes entering rooms, and chimney flues not in use. The Energy Saving Trust estimates that draughts account for 15 to 25 percent of total home heat loss in a typical UK home (Energy Saving Trust, 2026).
Sealing these gaps is one of the most cost-effective energy efficiency measures a homeowner can take, often paying for itself within a year or two. The key is to identify every point where air can pass through the building fabric and apply an appropriate sealant or mechanical excluder.
How to verify an installer or choose the right certification for DIY work
For professional draught-proofing, use an installer registered with TrustMark and MCS if the work is part of a wider insulation package. Check the Gas Safe Register if sealing around gas appliances to ensure vents are not blocked. DIY materials must meet British Standard BS 476-7 for fire resistance if used near chimneys or flues (GOV.UK, 2026).
No statutory certification is required for draught-proofing alone, but homeowners should check building regulations Part L (conservation of fuel and power) when combining it with other insulation work. Use the MCS register or TrustMark website to find local accredited installers (GOV.UK “Find a TrustMark trader” page, 2026).
how to find a certified insulation installer
Draught-proofing by room, typical gaps and sealing methods
In the living room, seal an unused chimney with an inflatable balloon costing £15 to £40, apply foam strips to window frames, fit a brush strip to the bottom of the door, and use silicone sealant along skirting boards. In the kitchen, fit a letterbox excluder, a closing flap on the extractor fan, a door brush, and window strips, but never seal gas boiler air vents. In the bathroom, apply window strips, fit an extractor fan cover that allows the fan to operate, and seal around pipe entry points under the sink with silicone. In the bedroom, fill floorboard gaps with acrylic caulk or wood filler, fit a door brush, apply window strips, and install keyhole covers. In the hallway, fit a door brush on the external door, a letterbox excluder, a keyhole cover, and seal around any cat flap if present.
Each room requires a specific combination of materials based on the gaps present. A systematic approach starting with the largest gaps, typically around doors and chimneys, yields the fastest return on investment.
When draught-proofing is not enough, ventilation requirements you must keep
Gas boilers, open-flue gas fires, and wood burners need a permanent air supply, and their vents must never be sealed. The Gas Safe Register technical guidance states that blocking these vents can cause carbon monoxide buildup (Gas Safe Register, 2026). Trickle vents on windows must stay open or be adjusted, not blocked; building regulations Part F (ventilation) requires minimum background ventilation (GOV.UK, 2026).
Extractor fans in kitchens and bathrooms must remain functional. Use draught-excluding covers that open when the fan runs and close when it stops. If you have cavity wall or loft insulation, draught-proofing first can cause condensation if ventilation is reduced. Check with a retrofit coordinator if unsure about the balance between sealing and ventilation in your home.
ventilation requirements after insulation upgrades
