In an average British dwelling about 26%* of the heat is lost through the roof. Installing loft insulation will substantially cut this heat loss, making the rooms below more comfortable and easier to heat. Loft insulation is effective for at least 40 years and it should pay for itself many times over.
There are two main ways of insulating the loft: Either putting insulation down between the joints of the floor of your attic, or by installing insulation between and over the rafters.
Insulating the floor of your attic, is cheap, quick and could be done by yourselves if your loft is easy to access. If there are no damp or condensation problems you could also use the attic for storage, one you put boards across the insulation. Insulating the roof between the rafters will make your attic more comfortable and usable, but it will need to be done by trained installers and cost more.
For a typical semi-detached home, the cost for loft insulation could be around £300, but the annual saving might £135, making this one of the most cost effective measures in an uninsulated house. Even if your loft has already been equipped with some insulation, if it is less than 200mm (8 inches) it will be worth adding more.
There is some additional information on types of loft insulation and how to go about it online:
Energy saving Trust: https://energysavingtrust.org.uk/home-insulation/roof-and-loft
Simple Energy Advice: https://www.simpleenergyadvice.org.uk/measures/meta_loft_insulation
Certain households might be entitled to support under the Energy Company Obligation (ECO). Under this scheme medium and larger energy suppliers may fund the installation of certain energy efficiency measures. Find out more information about the scheme and if your eligible via Ofgem: