Losing heat from your home

Losing heat from the home

Losing heat from your home?? Don’t Let the Heat Out!

With the high cost of heating oil and the average temperatures of Irish winters, everybody has a reason for concern about losing indoor warmth to the outdoors. It’s a fact of basic physics that heat travels from warm areas to colder areas, e.g. the outside of a heated building. If the temperature outside is colder than that indoors, heat will travel out of the house – if you let it.

Where Does The Heat Go?

Extensive studies have shown that about 35% of heat is lost through walls, 25% through the roof, 15% through doors, 15% through the floor and 10% through the windows. The percentages vary from building to building, but the essential point is that unless you take preventive measures you’re going to pay dearly to stay warm. Some of these measures cost nothing, though anything you spend on effective heat loss prevention is a good investment in the long run.


With cavity walls – designed to keep outside moisture away from the inner wall – good insulation will also be moisture-resistant, and it is probably the most cost-effective action you can take to prevent heat loss if none is already in place. A proper installation will cost you several hundred pounds, but the savings per year can return your investment in just three or four years.

With solid walls insulation can be added on the interior or exterior, but this is a bigger job and you may want to concentrate on the windows, which also leak a lot of heat if they are not well sealed.

Windows & Doors

Double-glazing is ideal, but it does cost upwards of £75 for an average window, and you can get thermal lined curtains for around £20 that will save almost as much heat if you remember to close them at dusk, including those in rooms not in use.

Draughts around windows and doors are common, but they can be drastically reduced with strips of plastic-covered foam or rubber compression seals, available in a variety of types and sizes. You can also get sealants made of silicone or polyethylene that come in tubes; you simply squeeze them into cracks and gaps that are too small or irregular for sealing strips.

Maximising Heat Retention

Further suggestions include keeping an aluminium reflector sheet behind any radiator that’s attached to an outside wall, and filling any gaps between floor boards and skirting boards with material such as newspaper or plastic. More heat escapes through the roof than through floors, so be sure the attic space is insulated between ceiling joists. Both mineral fibre quilts and insulation made from natural wool are available in almost any DIY store; they’re both very affordable and quite simple to install.

Remember that the sun provides heat even on cold days; get all the free solar heat available with the curtains open, then close them to help keep it inside. Avoid hanging curtains over radiators, as they can serve to direct the heat out the window instead of into the room. Close off any unused rooms; you’ll retain more heat in the lived-in parts. If you don’t have thick carpets, add as many rugs as possible; they can make everything look and feel much warmer.