Home Energy Efficiency UK 2026 — Grants, Upgrades and Savings GuideDraught-Proofing Costs UK — Savings, DIY Tips & Where to Start
How much draught-proofing costs in the UK, how much you can save on energy bills, DIY vs professional options, and what to prioritise.
Draught-proofing is the cheapest and easiest way to cut your energy bills. Here’s what to do and how much it costs.
At a Glance
| Feature | Detail |
|---|
| What it is | Sealing gaps and cracks that let cold air in and warm air out |
| Average saving | ~£60/year on energy bills (Energy Saving Trust) |
| DIY cost | Under £50 for a whole house |
| Professional cost | £200–£500 for a full house |
| Payback period | Under 1 year (DIY) |
| Difficulty | Easy — most draught-proofing is a simple DIY job |
| Safety warning | Do NOT draught-proof rooms with gas appliances — they need ventilation |
Where Draughts Come From
| Source | How much heat it loses | Priority |
|---|
| Windows | Up to 20% of heat loss | High |
| External doors | Significant — especially old or ill-fitting doors | High |
| Letterbox | Direct route for cold air | High |
| Chimney (unused) | Up to 40% of a room’s heat can escape | High |
| Floorboards | Gaps between boards let cold air in from below | Medium |
| Loft hatch | Warm air escapes into the loft | Medium |
| Pipework/cable holes | Small gaps around pipes entering the house | Medium |
| Skirting board gaps | Gaps between skirting and wall/floor | Low |
| Keyholes | Small but noticeable on windy days | Low |
Costs — DIY
| Item | What it does | Cost |
|---|
| Self-adhesive foam tape | Seals gaps around windows and doors | £2–£5 per roll |
| Rubber or silicone strip | More durable than foam for windows/doors | £5–£10 per strip |
| Brush strip (for bottom of doors) | Seals gap under doors while allowing them to open | £5–£15 |
| Letterbox draught excluder | Covers the internal letterbox opening | £5–£15 |
| Chimney balloon / Chimney Sheep | Blocks the chimney flue (when not in use) | £15–£30 |
| Keyhole cover | Swivelling plate over the keyhole | £3–£8 |
| Decorator’s caulk / filler | Seals gaps around window frames, skirting, floorboards | £3–£6 per tube |
| Self-adhesive compression strip (for loft hatch) | Seals the loft hatch | £5–£10 |
| Expanding foam (for larger gaps around pipes) | Fills larger gaps where pipes or cables enter | £5–£8 per can |
Total DIY Cost for a Typical 3-Bed Semi
| Area | Materials cost |
|---|
| Windows (6) | £15–£30 |
| External doors (2) | £10–£25 |
| Letterbox | £5–£15 |
| Chimney | £15–£30 |
| Floorboards | £5–£10 |
| Loft hatch | £5–£10 |
| Pipe holes | £5–£8 |
| Keyholes | £3–£8 |
| Total | £60–£135 |
Costs — Professional
| Service | Cost |
|---|
| Single window draught-proofing | £50–£80 |
| Single door draught-proofing | £60–£100 |
| Full house draught-proofing | £200–£500 |
| Sash window specialist draught-proofing | £100–£200 per window |
Energy Savings
| Property type | Estimated annual saving |
|---|
| Detached house | £70–£90 |
| Semi-detached house | £55–£65 |
| Mid-terrace | £40–£55 |
| Flat | £30–£50 |
Figures based on Energy Saving Trust estimates for a gas-heated home.
How to Draught-Proof: Room by Room
Windows
| Method | Best for | How to |
|---|
| Self-adhesive foam strip | Casement windows | Stick around the frame where the window closes |
| Rubber/silicone strip | Casement windows (more durable) | Press into the groove around the frame |
| Brush strip (sash windows) | Sliding sash windows | Fit into the gap between sash and frame |
| Secondary glazing | All windows (extra insulation) | Fit a second pane inside — £40–£100/window |
Doors
| Method | Cost | How to |
|---|
| Brush strip (bottom) | £5–£15 | Screw or stick to the bottom of the door |
| Foam/rubber strip (frame) | £2–£10 | Stick around the door frame |
| Keyhole cover | £3–£8 | Screw over the keyhole |
| Letterbox excluder | £5–£15 | Fit brush or flap behind the letterbox |
Chimney
| Method | Cost | Notes |
|---|
| Chimney balloon | £15–£25 | Inflate inside the chimney. Remove before lighting a fire |
| Chimney Sheep | £15–£30 | Felted wool plug. Sits in the flue. Easy to remove |
| Chimney cap (permanent) | £50–£150 | Professional fitting. For chimneys never used |
Floors
| Method | Cost | Notes |
|---|
| Filler between floorboards | £3–£6/tube | Use flexible filler — rigid filler will crack |
| Rugs | Varies | Quick fix for draughty floors |
| Underfloor insulation (more extensive) | £300–£1,000+ | Professional job if access is available |
Grants and Financial Help
| Scheme | Detail |
|---|
| ECO4 | Free draught-proofing for eligible households (certain benefits, EPC band D–G) — contact your energy supplier |
| Local authority schemes | Many councils offer free or subsidised draught-proofing — check your council’s website |
| Home Energy Scotland | Free advice and grants for Scottish households |
| Nest scheme (Wales) | Energy efficiency advice and potential free improvements |
| Warm Home Discount | Doesn’t directly fund draught-proofing but reduces bills by £150 |
Safety Warnings
| Warning | Detail |
|---|
| Gas appliances | Do NOT draught-proof rooms with gas boilers, gas fires, or gas cookers — they need ventilation |
| Extractor fans | Do NOT block bathroom or kitchen extractor fans |
| Air bricks | Do NOT block air bricks in walls — they provide essential ventilation |
| Trickle vents | Do NOT seal the trickle vents on double-glazed windows |
| Condensation | Excessive sealing without adequate ventilation can cause damp and mould |
| Listed buildings | Check with your local authority before making changes to listed properties |
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