The Energy Performance Certificate gives you a measure of your homes fuel cost based on ‘standard occupancy’. It recommends energy efficiency measures that help you reduce your fuel bills. The certificate shows you on a scale from A-G how energy efficient your home is (similar to the ratings that exist for washing machines, fridges and new cars). It also rates the CO2 emissions that your home produces. The ratings do not penalise you for having a larger property as they take into account the size of the property, (rating it in terms of an average square metre). The most efficient homes have a band A rating although there are very few of them. The average property in the U.K. is band D or E for both ratings. The ratings are based on the performance of the building and its services, such as heating and lighting (rather than the domestic appliances within it).

Statistics show that only 12% of heat loss in an uninsulated property is lost through drafts and ventilation. The other 88% is lost through the fabric of the building (i.e. the roof, walls, windows and doors). Some energy saving measures can dramatically reduce that heat loss with very little effort and money. For example, fitting 250mm thick loft insulation could cut heat loss through the roof by about 30%. Likewise, having an uninsulated cavity wall filled with blown fibre insulation could also produce a 30% reduction in heat loss through the walls. Other recommendations may include low energy light bulbs, insulated jackets for the hot water cylinder and upgrading the heating system and controls. The estimated cost of the measures recommended will vary, so the certificate splits the recommendations into 3 categories based on cost. Those that cost under £500, those that could cost more than £500, and further measures that will help achieve the highest possible ratings for the home but which could be expensive (typically taking more than seven years to repay their cost in energy savings).