Heating our homes in winter uses a lot of energy and many people’s bills are rising as fuel prices rise. Read on for tips to reduce your energy used for heating - they will save you money and also reduce your impact on climate change.

Tips for keeping warm:

  1. Simple ways to keep warm

  2. Cutting out draughts

  3. Insulating the loft

  4. Insulating the walls

  5. Double and triple glazing

  6. Passive solar heating

Overview

In the UK, the weather causes enough variability of the outside temperature for us to still need heating in winter even though climate change is causing a steady increase in global average temperatures. The comfort zone for most people lies between 20 and 24°C depending on the humidity. When the outside temperature is more than a few degrees different from this range the indoor temperature eventually begins to feel too hot or too cold.

Besides using heating, there are other simpler, cheaper and more environmentally friendly strategies that can be used to maintain a comfortable temperature in the home. These include insulating your home and cutting out drafts. Further information and advice are available free from the environment centre (02380 336 172).


Sources of heat loss from a typical uninsulated home

CO2 impact

If you can reduce the amount of heating needed to maintain your home within the comfort zone, then you will save on electricity and/or gas and therefore reduce your carbon dioxide emissions.

Money aspects

Reducing the use of heating will obviously reduce your gas and/or electricity bills. Most of the methods that insulate homes and otherwise improve the thermal environment within the home cost less than £500 and grants may be available.

Other benefits

These simple suggestions will tend to improve your thermal comfort rather than save you a lot of money but nevertheless can have health benefits. Keeping warm in winter is important for staying healthy, particularly for the elderly. Double or triple glazing will reduce traffic noise on busy main roads.

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1. Simple ways to keep warm

Around 20% of the heat in a house can be lost through single-glazed windows. This loss can be reduced by closing the curtains at dusk. If the curtains are heavily lined and overlap at the join, they are 75% as effective as double glazing. If you fit blinds as well as curtains, this is even more efficient at trapping air and also helps to cut down draughts.

If you have radiators fitted to external walls it helps to paste reflective metal foil behind each radiator with heavy duty wallpaper adhesive; this slightly reduces the heat lost through the outside wall. Special foil can be bought from DIY stores. Have alook at this article from the Guardian about putting foil behind your radiators. 

CO2 impact

The above suggestions will help to keep your home warmer and therefore may help you to cut down on your demand for heating. In that case your carbon dioxide emissions will also be reduced.

Money aspects

The above suggestions are more likely to increase your comfort than to save you a lot on your heating bills.

A roller blind costs upwards of £50 depending on the size of window. Curtain lining is relatively inexpensive and is easy to add if you have a sewing machine. Heat-reflecting foil costs around £4-6 per square metre.

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2. Cutting out draughts & Ventilation

Draughts

Did you know that only a quarter of homes in the UK are adequately draught proofed? As much as 20% of the heat loss from a typical home can be attributed to ill-fitting windows and external doors. Draughts can also occur around ill-fitting pipes, around other items that penetrate external walls, through the boards of suspended wooden floors and through loft hatches.

Simple things you can do include:

  • fit keyhole covers to external doors;

  • fit a draught-proof letterbox cover;

  • fill any draughty gaps in the structure of the house, for example between a window frame and the wall, with a silicone sealant;

  • use a self-adhesive foam strip which sticks to doors, window frames and loft hatches and is compressed when the opening is closed;

  • fit a threshold draught excluder to the bottom edge of outside doors.

Sash windows in older wooden frames can be especially hard to draught-proof: click here for advice. Gaps between floorboards can be sealed by laying flooring grade hardboard over the whole floor. Quarter-round lengths of wooden beading can be used to fill large gaps under skirting boards.

Ventilation

Remember that the purpose of draught proofing is NOT to exclude all fresh air from your home. You must ensure that ventilation is controlled and that your home feels comfortable. Stagnant air causes drowsiness as carbon dioxide levels rise. Bathrooms and kitchens need more ventilation to get rid of steam and water vapour which can otherwise lead to condensation on walls and windows which can encourage the growth of mould.  You can reduce kitchen and bathroom heat loss, whilst maintaining adequate ventilation, with heat recovery units. These are boxes containing a plate heat exchanger with supply and extract fans. They maintain balanced air supply in a room and pre heat the incoming air from the warm extracted air without the moisture.

DANGER - CARBON MONOXIDE (CO)

CO is present in exhaust from nearly all fires and stoves burning fuels. Modern houses are being built without fireplaces and chimney stacks, to reduce cost. These must have recommended ventilation for heating appliances such as gas fires. Do not block up air bricks and ventilation openings designed to provide adequate air supply. If units do not have the specified ventilation for the heating product, there is a danger that carbon monoxide will build up in the room. It is an odourless gas and a silent killer. 

CO2 impact

It has been estimated that fitting draught proofing can save the emission of 140-155 kg of carbon dioxide per year.

Money aspects

Draught proofing is one of the most inexpensive but effective ways of making your home more energy efficient and more comfortable. Nearly all the materials listed above can be bought for under £20 each and they can all be fitted by any competent DIY enthusiast. Your efforts may save around £25 per year on your heating bills. Buy and fit a carbon monoxide (CO) monitor alarm for about £25.

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3. Insulating the loft

This is the first item to tackle. Over a quarter of the heat loss from uninsulated homes goes out through the roof, because heat rises; yet this can be cut substantially by using suitable thermal insulation. Indeed, loft insulation is the single most cost-effective, low risk, energy-saving measure that can be applied to existing homes. 

Under pitched or sloping roofs, insulation is normally added between and over the horizontal joists across the floor of the loft. It is recommended that this insulation is 600mm (2 ft), thick glass fibre matting, depending upon its density. A variety of other materials can be used, in quilt or loose form, ranging from renewable cellulose and sheep’s wool to more effective mineral wool. The insulation material should not be pushed up against the sloping rafters: a gap of 25 mm (1 inch) must be left to allow air to circulate. If there is a cold water tank in the roof, insulation should be lapped up against it, and not placed underneath, to allow heat to rise under the tank and prevent the water freezing.

If the loft space has been converted into a living space, then insulation has to be applied between the sloping rafters on the underside of the roof. Suitable materials include mineral wool and polystyrene in various forms including spray foams, rolls and rigid slabs. Where space is limited, you can use multifoil insulation. In most cases a 50mm (2 inch) ventilated airspace must be provided between the upper surface of the insulation and the tiling underlay.

Flat roofs can also be insulated but it is most cost effective to add or replace the insulation in a flat roof when the roof covering needs renewing; at approximately 15 to 20 year intervals.

Find a registered installer through the National Insulation Association (NIA)

CO2 impact

The savings you make in carbon dioxide emissions will depend on how much loft insulation you already have and its condition. If you have none at all, you might save around 1000 kg a year, but if you are starting from 50 mm (2 inches) the annual saving may only be around 250 kg.

Money aspects

The savings you make will depend on how much loft insulation you already have and its condition. If you have none at all, you might save around £175 per year, but if you are starting from 50 mm (2 inches) the saving may only be around £40 per year. If you do it yourself it costs around £5.50 per square metre to lay 250 mm thick glass fibre and around £20 per square metre to use wool. Professional installation may cost around £750-£1,000. 

Grants may be available to cover the total cost of insulation (including fitting) for those aged 70 or over, or in receipt of certain benefits, and discounts are available to others.

Other benefits

As with many other types of home insulation, you will find that insulating your loft or roof keeps rooms immediately under the roof warmer in winter and cooler in summer, as well as saving money and carbon dioxide emissions.

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4. Insulating the walls

Insulating your external walls will keep your home warmer in winter.

If you live in a house built since the 1920s it probably has “cavity walls”, ie an air cavity at least 50 mm (2 inches) wide between the inner and outer skins of the building. This cavity can be filled with an insulating material such as mineral wool or vermiculite beads that  traps air, prevents air movement, and therefore insulates the wall. Static air is a good insulator. Cavity wall insulation is the second most cost-effective, low risk, energy-saving measure (after loft insulation) that can be applied to existing homes.

Cavity wall insulation can be installed without major disruption to a building’s occupants, usually in a single day, and it needs no maintenance. The installation has to be done by a specialist company and involves drilling a series of one-inch diameter holes between the bricks in the outer wall and then injecting the material through them under pressure; then sealing the holes.

Caution

It is best not to use the original solid foam insulation. This seals the ends of joists and rafters housed in the inner skin, which can become damp and develop wet rot.

Find a registered installer through the Cavity Insulation Guarantee Agency (CIGA) or the National Insulation Association (NIA) .

If your house has a solid brick wall (you can tell from the pattern of the external brickwork: bricks in solid walls were laid alternately end-on and sideways-on), insulation can be applied either from the inside (making the rooms slightly smaller) or the outside. These are more complex undertakings and you should seek professional advice before deciding to go down this route. Find out more here.

CO2 impact

The average house can reduce its emissions by about one sixth by installing cavity-wall insulation - this could lead to a saving of 750 kg of carbon dioxide per year.

Money aspects

It costs around £500-£1,500, depending on size and type of house, to install cavity-wall insulation, but it can pay for itself through reduced heating bills within 5 years.

Grants may be available to cover the total cost of insulation for those aged 70 or over, or in receipt of certain benefits, and discounts are available to others.

Other benefits

The most immediate benefit noticed by many home owners, after cavity-wall insulation has been installed, is that the rooms are warmer and have a more even temperature. The house will stay warmer longer in winter and cooler longer in summer. There will be less condensation on external walls and fewer draughts.

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5. Double and triple glazing

Homes may lose as much as 20% of their heat through single-glazed windows. This can be reduced significantly by installing double-glazing (over twice as good as single glazing) or, better still, triple glazing with low-emissivity glass (up to 12 times better). See also lined curtains, above. As with walls, using air trapped between outer and inner glass panels is good insulation. Replacement windows normally have sealed, double glazed panels filled with an inert gas, which prevents condensation from forming.

However, before deciding to embark on double-glazing, you should be sure that you have addressed all other means of insulation, as they are likely to be more cost-effective. You might even consider adding secondary glazing on the inside of the existing windows instead, particularly if they are in good condition with draught-proof frames.

If you do go ahead, it is frequently necessary to change the window frames at the same time, in which case planning consent may be required - the new windows may be too thick for the existing frames and the new frames must be draught-proof.

Kits are available, but for most people it is better to employ a specialist firm. Further information, including details of local suppliers, is available from the Glass and Glazing Federation and British Fenestration Rating Council. The Building Research Establishment’s Green Guide gives information and a summary environmental rating for different types of construction. Always look for the ‘Energy Saving Recommended’ logo when choosing your windows - that way you can be sure they are the most energy efficient as the whole window (frame and glass) is assessed on a rating scale from A to G by the British Fenestration Rating Council.

CO2 impact

It is estimated that an average house can save around 740 kg of carbon dioxide per year from installing double glazing. But if you chose uPVC frames, instead of wood or aluminium frames, considerable energy is required to make them which will offset some of the carbon dioxide savings you make. It is also said that uPVC frames may not last so long. These days some manufacturers of uPVC frames state that, like wood and aluminium, they can be recycled.

Money aspects

It is estimated that fitting double-glazing can save around £120 per year on your heating bills. On the other hand, fitting new double-glazed windows is expensive. Professionally fitted tertiary glazing over existing double glazing will cost about £800 per typical window.

Other benefits

Double and triple glazing cuts out noise as well as heat loss. This may be an important consideration for some home-owners.

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6. Passive solar heating

A suitably designed home can benefit from what is known as passive solar heating. This means using radiant heat from the sun to directly heat the air inside the home, and its fabric.

Older homes in UK have not been designed with this in mind, but even so some simple actions can help. For example, in winter, sunny days are often followed by cold nights. If you allow the sun to shine into your rooms by drawing back the curtains, but close them as soon as the sun sets, heat absorbed from the sun will heat up the interior after sunset.

A south-facing conservatory can be made to work in a similar fashion. The winter sun can heat up the floor and brick walls during the day and heat can be extracted into the house in the evening by a suitably placed fan.

A similar idea is used by a Trombe wall. This is a glazed, south-facing, dark-coloured wall with a large thermal mass. In winter, the wall heats up during the day and warm air is extracted into the house through vents at night.

CO2 impact

It is not possible to estimate how much any of the above suggestions may save in emissions simply because every home is different.

Money aspects

Adding a conservatory or Trombe wall to your house will involve a substantial investment. However, many people add conservatories to their houses these days and it is worth considering the advantages of passive solar heating at the planning stage. A Trombe wall can be added too but is probably best considered when planning a new building.

Other benefits

A conservatory obviously offers other advantages as a warm daytime space, particularly in spring or autumn, when it is cool outside; and for starting seeds and plant propagation.

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If you would like to give feedback on this site, or have any suggestions for improvement, please contact us. We are particularly keen to hear about other organisations and initiatives in and around Winchester which can help people reduce their carbon footprint.

The information on this page is provided in good faith and reflects our understanding of the underlying science and technology at the time of writing, but we cannot guarantee that it is wholly accurate. All figures for costs, savings and other matters are estimates: the actual figures will depend on your particular circumstances and may differ (perhaps significantly) from those shown. Although we have included links to various organisations, we are not recommending these organisations: it is your responsibility to check that they are suitable for your needs. Nonetheless, if you experience difficulties with any of the links or organisations, or believe that any of the information presented here is inaccurate, please let us know and we will update this page if we consider it necessary.