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Draught proofing / pipes and water tank insulation





Note: Savings above are possible after 5 years

If you already have good cavity wall insulation, roof and loft insulation as well as double glazing, there are still 2 other sources of fresh air entering your home, these being draughts and ventilation. The best way to reduce this heat loss is draught proofing your home. Not much of a problem if you can handle simple DIY jobs and most products should be available from good DIY shops.

Currently there are no grants to help you with draught proofing unless you live in the council of Cheshire East. This lack of grants means you will be looking at a payback period of up to 5 years depending on the work carried out and who does the work.

If you are serious about reducing heat loss you could employ someone with a thermal imaging camera who can scan the outside of your house and highlight any points where excess heat is lost.

Money saving tips

Draught-proofing is one of the cheapest and most efficient ways to save energy and money but still takes a few years to payback. Additionally, it’s important to know that the environmental benefit of a reduced CO₂e footprint due to insulation only starts once the embedded CO₂ in an insulation material as well as the CO₂ generated during its transport and installation is removed from the equation. Note: we will supply pay back periods at a later date.

Draught proofing costs and savingsCostAnnual saving
DIY installation£120£50
Professional installationaround £350£50

Windows without double glazing or poorly fitting double glazing

Buy draught-proofing strips to stick around the window frame and fill the gap between the window and the frame. There are two types:

Self-adhesive foam strips – low cost, and easy to install, but may not last long. Cost for 50m Cost – £40

Metal or plastic strips with brushes or wipers attached – long-lasting, but cost a little more. Make sure the strip is the right size to fill the gap in your window. If the strip is too big it will be crushed and you may not be able to close the window. If it’s too small there will still be a gap.

Sliding sash windows

Sliding sash windows are notorious for being draughty and foam strips do not work well. It’s best to fit brush strips or consult a professional. For windows that don’t open, use a silicone or foam sealant. This special type of foam can be sprayed into gaps around windows, however it is more expensive than the foam strips.

Cracks around windows and surrounding walls

Draughts also occur in cracks between the window frames and the surrounding walls – in this instance use sealant or putty for best results.


​Outside doors can be the source of heat loss but you can reduce this for just a few pounds. Here are the main things to consider.

Keyhole – buy a purpose-made cover that drops a metal disc over the keyhole. Cost – £5

Letterbox – use a letterbox flap or brush, but remember to measure your letterbox before you buy. Cost – £6

Gaps around the door – fit foam, brush or wiper strips similar to those used for windows.

Inside doors need draught-proofing if they lead to a room you don’t normally heat, such as your spare room or kitchen. Keep those doors closed to stop the cold air from moving into the rest of the house. If there is a gap at the bottom of the door, block it with a draught excluder – you can make one stuffed with used plastic bags, rice or bits of spare material. However, as a draught excluder isn’t fixed to the door, depending on where it lands when you close the door behind you, it may let in draughts when you’re out.

Inside doors between two heated rooms don’t need draught-proofing, as you don’t lose energy when warm air circulates.

​Loft hatches

Put strips of draught-excluding material around the hatch edges. Cost – £3

Electrical fittings on walls and ceilings

Use sealants to fill gaps around the fittings.

Suspended floorboards, skirting boards and ceiling-to-wall joints

Floorboards and skirting boards often contract, expand or move slightly with everyday use, so you should use a filler that can tolerate movement – these are usually silicone-based. Look for the following:

Flexible fillers.

Decorator’s caulk. Cost – £7

Mastic-type products

​Cracks in walls

You can fill in cracks using cements or hard-setting fillers, but if it’s a large crack there may be something wrong with your wall. Consult a surveyor or builder to see what caused the crack in the first place. Cost – £15

Pipework leading outside

You can fill small gaps around pipework leading to a loft or the outside with silicone fillers, similar to the fillers used for skirting boards and floorboards. Fill larger gaps with expanding polyurethane foam. This is sprayed into the gap, expands as it dries, and sets hard.

​Chimneys and fireplaces

Buy a chimney draught excluder – devices that help stop draughts and heat loss up the chimney, usually fitted within the chimney or around the fireplace. Cost – £30

Remember to remove the draught-proofing if you decide to light a fire!

Old extractor fans

Old fan outlets may need to be filled with bricks or concrete blocks and sealed from both the inside and outside.

​Disused vents

Disused vents may be left behind after gas fires and old central heating boilers, with non-balanced flues, are removed. These should be sealed up, perhaps with an adjustable vent cover, or you can fill them with expanding polyurethane foam. Cost – £15

You should block most of these – but be careful in areas that need good ventilation, such as:

Areas where there are open fires or open flues.

Rooms where a lot of moisture is produced, such as the kitchens, bathrooms and utility rooms.​

Damaged or worn parts of a building

For example, where brickwork needs re-pointing – add new or top-up mortar between the bricks.

Water tanks and pipes

If you have insulation between the joists in your loft, it will keep your house warmer but make the roof space above colder. Insulating pipes and water tanks in your loft will help prevent freezing and save energy. The consequences of a frozen pipe can be dire, the pipe can rupture and lead to flooding.

Pipe insulation consists of a foam tube that covers the exposed pipes between your hot water cylinder and boiler. It’s usually as simple as choosing the correct size from a DIY store and then slipping it around the pipes.

Insulate your hot water cylinder with at least an 80mm lagging jacket – a well fitted tank jacket could save you around £25 to £35 a year which is more than the cost of the jacket.

Cooler air in an insulated loft could mean that cold draughts come through the loft hatch. To prevent this fit an insulated loft hatch or foam board on polystyrene onto the inside of the door.

Hot water tank and pipe insulation –

Insulation typeFuel bill savings (£/year)DIY costPayback timeCarbon dioxide savings
​(kg CO₂/year) based on 10.33p per kWh gas
Hot water tank top up insulation (25mm – 80mm)£30Around £25Around 10 months55kg
Hot water tank jacket (80mm) on an uninsulated tank£80Around £25Around 4 months​147kg
​Primary pipe insulation£10Around £40Around 4 years18kg

This means you’ll have paid off the cost in less than seven years – and if you sell the property, it’s always great to be able to tell prospective buyers about your reduced energy bills.


Air needs to flow in and out of your house so it stays fresh, dry and healthy. Make sure you don’t block or seal any intentional ventilation, such as the following:

Extractor fans – they take out damp air quickly in rooms where lots of moisture is produced (kitchens, bathrooms and utility rooms)

Under-floor grilles or air bricks – help keep wooden beams and floors dry.

Wall vents – let small amounts of fresh air into rooms.

Trickle vents – modern windows often have small vents above them to let fresh air trickle in.

Keep good ventilation in areas where there are open fires or flues and in rooms where moisture is produced.
​Don’t seal kitchen and bathroom windows – this lets out the steam and helps create ventilation. Instead, seal the inner doors to these rooms.

Look for the Kitemark

There are plenty of DIY stores that sell draught-proofing materials, but look for draught-proofing with a Kitemark – this shows that the product is made to a high standard. British Standard Institution accredited products have a 20-year life when correctly installed and maintained.