Controlled ventilation helps reduce condensation and damp, by letting fresh air in when needed. However, draughts are uncontrolled: they let in too much cold air and waste too much heat. To draught-proof your home you should block up unwanted gaps that let cold air in and warm air out. Saving warm air means you’ll use less energy to heat your home, so you'll save money as well as making your home snug and pleasant. Draught-proofing around windows and doors could save you £25 to £35 per year. Draught-free homes are comfortable at lower temperatures – so you may be able to turn down your thermostat saving even more on your energy bills. Draughts happen where there are unwanted gaps in the construction of your home, and where openings are left uncovered. You’ll find draughts at any accidental gap in your home that leads outside, such as: You should block most of these – but be careful in areas that need good ventilation, such as: If you’re happy carrying out simple DIY tasks, draught-proofing will be no problem.
However, some homes, especially older homes with single glazing, will be more difficult to draught-proof. Professional draught-proofing is likely to save more energy because the installer will know exactly the right materials to use and where to use them. 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 good standard. British Standard Institution accredited products have a 20-year life when correctly installed and maintained. For windows that open, 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 – cheap, and easy to install, but may not last long. 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 get crushed and you may not be able to close the window.
If it's too small there will still be a gap. For sliding sash windows, 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 sealant. Draught-proofing outside doors can save a lot of heat and will only cost you a few pounds. There are four main things to consider. Keyhole – buy a purpose-made cover that drops a metal disc over the keyhole. Letterbox – use a letterbox flap or brush, but remember to measure your letterbox before you buy. Gap at the bottom – use a brush or hinged flap draught excluder. Gaps around the edges – fit foam, brush or wiper strips like 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 or bits of spare material.
Inside doors between two heated rooms don’t need draught-proofing, as you don’t lose energy when warm air circulates. If you don’t use your fireplace, your chimney is probably a source of unnecessary draughts. There are two main ways to draught-proof a chimney: Fit a cap over the chimney pot – this might be better done by a professional; buy a chimney draught excluder – devices that help stop draughts and heat loss through the chimney, usually fitted within the chimney or around the fireplace. Remember to remove the draught-proofing if you decide to light a fire! Floorboards and skirting boards You can block cracks by squirting filler into the gaps. 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: Fillers come in different colours, and for indoor and outdoor use. They block gaps permanently so be careful when you apply them – wipe off any excess with a damp cloth before it dries.
Fillers may break down over time, but can easily be reapplied. Check whether you also need to insulate between the skirting board and the floor. Hot air rises and gets lost into the cold space in your loft or attic, so it’s worth blocking off draughts around your loft hatch. Use strip insulation, as you would on a door. You can fill small gaps around pipework 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. Old fan outlets may need to be filled with bricks or concrete blocks and sealed from both the inside and outside. 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. 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:Energy Efficiency and Historic Buildings: Draught-proofing windows and doors Published 29 April 2016 This guidance note provides advice on the principles, risks, materials and methods for improving the thermal performance of existing windows and doors by draught-proofing. Draught-proofing is one of the most cost effective and least intrusive ways of improving the comfort of occupants and reducing energy used for heating with little or no change to a building’s appearance. It also has the added benefit of helping to reduce noise and keeping out dust. Research has shown draught-proofing can reduce air leakage from windows by between 33% and 50%, therefore significantly reducing the heating requirement needed for the room.Historic windows and doors make a major contribution to the significance and character of historic buildings and areas so every effort should be made to retain them rather than replace them.
Windows and doors can tell us a lot about the history of a building, changing architectural taste and style, social hierarchy, building economics, craft skills and technical advances.Older buildings are prone to heat loss through cracks and gaps which develop as various building elements move and distort over a long period. This is often the case for windows and doors which can be a major source of heat loss. However, less than a quarter of the heat lost through a typical traditional window escapes by conduction through the glass, the rest is by draughts (air infiltration). Since draughts make people feel colder, the occupants often turn up the heating and run it for longer.Windows and doors should be assessed for repairs before embarking on any draught-proofing measures. Traditional windows and doors can almost always be repaired, even if in very poor condition. This guidance forms one of a series of thirteen guidance notes covering the thermal upgrading of building elements such as roofs, walls and floors.
First published by English Heritage March 2012 (51680). IntroductionRepairing windows and doorsDraught-proofing rather than double glazingIssues to consider before draught-proofingDraught-proofing and the Building RegulationsDraught-proofing productsWhere to get advice Series: GuidancePublication Status: CompletedPages: 24Product Code: HEAG084 If you require an alternative, accessible version of this document (for instance in audio, Braille or large print) please contact us: Telephone: 0370 333 0607 Textphone: 0800 015 0516 I Want to Alter My Windows It’s important to know your windows before deciding on work to them. Historic windows are important additions to your home. I Want To Alter A Door Historic doors - both internal and external - play a key role in your house's character and should be retained wherever possible. How to Save Energy in Older Houses Follow our practical advice on how to save energy in older buildings. How to improve the energy efficiency of older buildings in ways that are sympathetic to their historic character.