Home Energy Efficiency UK 2026 — Grants, Upgrades and Savings Guide

Draught-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

FeatureDetail
What it isSealing gaps and cracks that let cold air in and warm air out
Average saving~£60/year on energy bills (Energy Saving Trust)
DIY costUnder £50 for a whole house
Professional cost£200–£500 for a full house
Payback periodUnder 1 year (DIY)
DifficultyEasy — most draught-proofing is a simple DIY job
Safety warningDo NOT draught-proof rooms with gas appliances — they need ventilation

Where Draughts Come From

SourceHow much heat it losesPriority
WindowsUp to 20% of heat lossHigh
External doorsSignificant — especially old or ill-fitting doorsHigh
LetterboxDirect route for cold airHigh
Chimney (unused)Up to 40% of a room’s heat can escapeHigh
FloorboardsGaps between boards let cold air in from belowMedium
Loft hatchWarm air escapes into the loftMedium
Pipework/cable holesSmall gaps around pipes entering the houseMedium
Skirting board gapsGaps between skirting and wall/floorLow
KeyholesSmall but noticeable on windy daysLow

Costs — DIY

ItemWhat it doesCost
Self-adhesive foam tapeSeals gaps around windows and doors£2–£5 per roll
Rubber or silicone stripMore 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 excluderCovers the internal letterbox opening£5–£15
Chimney balloon / Chimney SheepBlocks the chimney flue (when not in use)£15–£30
Keyhole coverSwivelling plate over the keyhole£3–£8
Decorator’s caulk / fillerSeals 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

AreaMaterials 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

ServiceCost
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 typeEstimated 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

MethodBest forHow to
Self-adhesive foam stripCasement windowsStick around the frame where the window closes
Rubber/silicone stripCasement windows (more durable)Press into the groove around the frame
Brush strip (sash windows)Sliding sash windowsFit into the gap between sash and frame
Secondary glazingAll windows (extra insulation)Fit a second pane inside — £40–£100/window

Doors

MethodCostHow to
Brush strip (bottom)£5–£15Screw or stick to the bottom of the door
Foam/rubber strip (frame)£2–£10Stick around the door frame
Keyhole cover£3–£8Screw over the keyhole
Letterbox excluder£5–£15Fit brush or flap behind the letterbox

Chimney

MethodCostNotes
Chimney balloon£15–£25Inflate inside the chimney. Remove before lighting a fire
Chimney Sheep£15–£30Felted wool plug. Sits in the flue. Easy to remove
Chimney cap (permanent)£50–£150Professional fitting. For chimneys never used

Floors

MethodCostNotes
Filler between floorboards£3–£6/tubeUse flexible filler — rigid filler will crack
RugsVariesQuick fix for draughty floors
Underfloor insulation (more extensive)£300–£1,000+Professional job if access is available

Grants and Financial Help

SchemeDetail
ECO4Free draught-proofing for eligible households (certain benefits, EPC band D–G) — contact your energy supplier
Local authority schemesMany councils offer free or subsidised draught-proofing — check your council’s website
Home Energy ScotlandFree advice and grants for Scottish households
Nest scheme (Wales)Energy efficiency advice and potential free improvements
Warm Home DiscountDoesn’t directly fund draught-proofing but reduces bills by £150

Safety Warnings

WarningDetail
Gas appliancesDo NOT draught-proof rooms with gas boilers, gas fires, or gas cookers — they need ventilation
Extractor fansDo NOT block bathroom or kitchen extractor fans
Air bricksDo NOT block air bricks in walls — they provide essential ventilation
Trickle ventsDo NOT seal the trickle vents on double-glazed windows
CondensationExcessive sealing without adequate ventilation can cause damp and mould
Listed buildingsCheck with your local authority before making changes to listed properties

Sources

  1. Energy Saving Trust