The A to G scale
AN ENERGY Efficiency Certificate is produced using an alphabetical scale from A to G illustrated by a coloured bar chart. The most energy efficient homes are in band A and the least energy efficient in band G. Those properties in band A should have the lowest energy bills. The same scale is used to define the impact a home has on the environment. Better-rated homes should have less impact through carbon dioxide (CO2) emissions.
The average home in Spain achieves band E or F for both ratings. New houses with a good level of energy efficiency are capable of obtaining a D rating, whilst some old properties will be in the lowest G category.
Home owners are not under any obligation to improve the energy efficient rating of a property, though it should be borne in mind how a very low rating may effect the sale, or ability to rent, on the open market.