Draught Proofing: Does It Reduce Heating Costs?

What Is Draught Proofing?

Draught proofing involves sealing unwanted gaps in your home that let cold air in and warm air out.

Draughts occur when cold air enters your home through gaps and cracks, or when warm air escapes through the same openings [S1]. Common draught sources include gaps around windows and doors,裂缝 in floors and skirting boards, loft hatches, letter boxes, keyholes, and pipe entries through walls.

Draught proofing uses materials such as foam strips, brush strips, silicone sealant, and expanding foam to seal these gaps [S1]. The goal is to stop draughts while maintaining necessary ventilation in rooms that need it, such as bathrooms and kitchens with gas appliances.

• Gaps around windows and doors are the most common draught sources
• Floors, skirting boards, and loft hatches also allow significant heat loss
• Letter boxes, keyholes, and pipe entries are often overlooked
• Materials include foam strips, brush strips, sealant, and expanding foam
• Do not seal rooms that require ventilation for health and safety [S2]

How Much Can Draught Proofing Save?

The Energy Saving Trust estimates annual savings of £45-65 for a typical semi-detached house.

The amount you save depends on the size of your home, how draughty it currently is, and how thoroughly you seal the gaps [S1]. A terraced house may save £30-45 per year, while a detached house could save £60-80 per year. These savings come from reduced heating demand, as your heating system does not need to work as hard to maintain temperature.

Draught proofing also improves comfort by eliminating cold spots and reducing noise from outside [S1]. Many people notice the difference immediately, with rooms feeling warmer even at the same thermostat setting. This is because warm air is no longer being replaced by cold draughts.

• Terraced house: approximately £30-45 per year [S1]
• Semi-detached house: approximately £45-65 per year [S1]
• Detached house: approximately £60-80 per year [S1]
• Flat: approximately £20-35 per year
• Savings are approximate and depend on current draught levels

Where to Draught Proof in Your Home

Focus on the biggest sources of draughts first: doors, windows, floors, and the loft hatch.

Doors are often the biggest source of draughts. Gaps around the frame and at the bottom of the door allow cold air to enter and warm air to escape [S1]. Use self-adhesive foam or brush strips for the frame, and a draught excluder or automatic door bottom for the gap under the door.

Windows can be draughty due to gaps between the frame and the wall, or between the moving parts of the window. Foam strips or silicone sealant can seal frame gaps, while brush strips can seal moving parts [S1]. For single-glazed windows, consider secondary glazing as an additional measure.

• Doors: foam/brush strips for frames, draught excluder for bottom [S1]
• Windows: foam strips or sealant for frame gaps
• Floors: seal gaps between floorboards and skirting boards
• Loft hatch: foam strip around the edge, draught excluder brush
• Pipes and cables through walls: expanding foam or sealant
• Keyholes and letter boxes:专用 covers or brushes

Rooms to Avoid Draught Proofing

Do not draught proof rooms that require ventilation for health and safety, such as bathrooms and kitchens with gas cookers.

Some rooms need permanent ventilation to prevent damp, mould, and dangerous gas build-up [S2]. Bathrooms require ventilation to remove moisture from showers and baths. Kitchens with gas cookers need ventilation to prevent carbon monoxide build-up. Rooms with open fires or wood burners need ventilation for combustion air.

Building Regulations Part F requires certain levels of ventilation in habitable rooms [S2]. Blocking these ventilation paths with draught proofing can create health and safety risks. If you are unsure whether a room needs ventilation, consult a qualified installer or building control officer.

• Bathrooms: need ventilation to remove moisture [S2]
• Kitchens with gas cookers: need ventilation for combustion safety
• Rooms with open fires or wood burners: need combustion air
• Utility rooms with boilers: need ventilation for combustion and flue gases
• Rooms with extractor fans: ensure fans can still function properly
• Check Building Regulations Part F for ventilation requirements [S2]

DIY Draught Proofing Guide

Draught proofing is one of the easiest and cheapest energy-saving improvements you can do yourself.

Most draught proofing materials are self-adhesive and require no special tools. Foam strips come in rolls that you cut to size and stick into place [S1]. Brush strips slot into a carrier that screws to the door frame. Silicone sealant is applied with a gun to fill gaps around frames.

Start by identifying all draught sources on a cold, windy day. Feel around windows, doors, floors, and the loft hatch with your hand or a lit candle (the flame will flicker in a draught). Mark each draught source and then systematically seal them [S1]. Most houses can be fully draught proofed in a weekend.

• Identify draughts on a cold, windy day using your hand or a candle
• Buy self-adhesive foam strips, brush strips, and sealant from any DIY shop
• Cut foam strips to size and stick into place
• Screw brush strip carriers to door frames
• Apply silicone sealant to frame gaps with a sealant gun
• Test by re-checking with your hand or candle after installation

Draught Proofing vs Other Insulation

Draught proofing is the cheapest and easiest insulation measure, but it should be combined with loft and wall insulation for maximum benefit.

Draught proofing targets air leakage, while loft and wall insulation target heat transfer through solid materials [S3]. Both are important, but draught proofing offers the best return on investment because it is so cheap. A typical DIY draught proofing job costs £100-300 and saves £45-65 per year, giving a payback period of 2-5 years.

Loft insulation is the next most cost-effective measure, with 270mm of mineral wool saving approximately £215 per year for a detached house [S3]. Cavity wall insulation saves £150-250 per year. Draught proofing should ideally be done before loft or wall insulation, as it reduces the heating demand that insulation helps to meet.

• Draught proofing: £100-300 cost, £45-65/year saving, 2-5 year payback [S1]
• Loft insulation (270mm): £300-600 cost, £215/year saving, 1-3 year payback [S3]
• Cavity wall insulation: £500-1,500 cost, £150-250/year saving, 2-6 year payback
• Do draught proofing first as it is cheapest and easiest
• Combine measures for maximum benefit and comfort

Frequently asked questions

Bottom line

Draught proofing is one of the most cost-effective energy improvements available, saving £45-65 per year for a typical semi-detached house at a cost of just £100-300 for DIY materials. It is easy to install in a weekend and provides immediate comfort benefits. Do not seal rooms that need ventilation, such as bathrooms and kitchens with gas cookers. Combine with loft and wall insulation for maximum benefit.