Much like the multi-coloured sticker on new appliances, EPCs tell you how energy efficient a building is and give it a rating from A (very efficient) to G (inefficient). EPCs let the person who will use the building know how costly it will be to heat and light, and what its carbon dioxide emissions are likely to be. The EPC will also state what the energy-efficiency rating could be if improvements are made, and highlights cost-effective ways to achieve a better rating. Even if you rent your home, some improvements noted on the EPC may be worth implementing, such as switching to more energy-efficient light bulbs. EPCs are valid for 10 years from when issued.