Yes, no matter how efficient your heating system, it won’t keep you warm and run economically unless your home is well insulated. This is particularly true of older properties that are rarely insulated to the best modern standards. Bad insulation allows the heat to escape and cold air to enter, making your home cold and uncomfortable. Reviewing your insulation is a vital step for improving your energy efficiency, and should be carried out as alongside any improvements to your heating system. It’s particularly important if you are planning to add a renewable technology to your heating system.
The walls of a poorly insulated building may be losing about a third of all heat put into it. However, wall insulation has to be considered carefully because walls also have an important function to perform in keeping moisture out of your house.
If your home has cavity walls, an effective way to increase its thermal efficiency is to have cavity wall insulation installed. The insulating material can be pumped or blown into the wall cavity. Materials commonly used are mineral wool fibre, urea formaldehyde foam and expanded polystyrene beads.
For older properties that do not have cavity walls, there are methods of internal and external cladding. Solid walls let through twice as much heat as cavity walls so are well worth insulating. However, external cladding is expensive and planning permission may be necessary. Solid walls can also be insulated internally by battening them out and filling the space inside the battens with polystyrene, mineral wool or fibreglass and then covering the battens with plasterboard. This involves a great deal of work, including moving electrical sockets, skirting boards, radiators, door and window frames etc. Also, the size of the room is reduced, as the insulation must be at least 50mm thick.
For more information on cavity wall insulation, visit the National Insulation Association’s website.
The most commonly insulated part of a building is the roof space. It is an area of high heat loss - about a third of the heat put into a house is lost through the roof. It is often relatively easy to gain access to and the materials required are readily available and not too expensive. It is not a skilled job, but needs some agility and a very careful approach. Some Government grants for roof space insulation are available.
The majority of roofs are insulated by laying the insulation across the loft floor between the ceiling joists. The material that is used is mainly rolls of fibreglass matting and current building regulations require a minimum thickness of 270mm. Loft insulation is a very cost effective measure and you can expect it to pay for itself in as little as two years.
For more information on loft insulation, visit the National Insulation Association’s website.
It is essential for air to move in and out of the buildings we live and work in, or it would eventually be impossible to breathe in them. However, rapid movement of cold air in a building, known as draught, creates uncomfortable conditions and also wastes fuel by reducing the air temperature and increasing the amount of air the system has to heat beyond that which is necessary. Draught reduction is normally the most cost effective method of energy saving available. In many cases, expenditure on draught reduction is recovered in less than a year.
For more information on draught proofing, visit the National Insulation Association’s website.
Double glazing and ‘low e’ glass
A common way of improving the heat-retaining properties of windows is to place another layer or pane of glass on the inside, and trap the air between them. If the air can move freely between the panes, it can conduct heat across the inner space and reduce the insulating effect. For this reason, purpose-made sealed double glazing units normally have the air evacuated to leave a vacuum. The wider the gap between the panes of sealed units the better the insulating effect.
Double Glazing options include individual sealed units which fit directly into the brickwork, secondary glazing that fits inside the original single glazed window, and plastic film that can be fitted over window frames as a low cost DIY operation.
A further glazing option is ‘Low E’ glass coatings which work by reflecting or absorbing IR light (heat energy). The thickness of the Low E coating and its position in the window dictates how the window will perform.
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You can find some more general advice about energy efficiency here