25% of the heat generated in your house could be going through the roof!
Loft insulation is one of the most cost efficient ways of reducing your heating bills and is also easy to install.
The ideal thickness of loft insulation is about 200mm (8 inches), so if the insulation in your loft is less than this then you should top it up.
Loft insulation can be installed by anyone reasonably competent at DIY (do it yourself). Lay the insulation between the joists where possible, and then at right angles to the first layer when it reaches the top of the joists (most joists will be less than 4" high). Make sure the loft hatch is also insulated.