Dear owner: Last April 5th, the Spanish Council of Ministers passed the Royal Decree 235/2013 by which the basic proceedings for the Energy Performance Certificates in buildings were approved. This Royal Decree states that all properties sold or rented or advertised for those purposes, must have the Energy Performance Certificate as of June 1st. The Energy Performance Certificate provides information about annual energy consumption in normal conditions of use and occupation of the property. This is achieved considering, among others, the consumption of the heating, water heating and cooling systems, as well as the ventilation and lighting conditions. The certification process finishes with the expedition of the Energy Performance Certificate and the allocation of an energy label. This label helps compare the energy efficiency of different properties. The certificate, valid for 10 years, must be prepared by technicians authorised for this purpose. It is important for the technicians to perform their job well, since bad energy efficiency grading would unjustly reduce the value of your property in the real estate market. Evidently, those properties with worst grading will be less attractive for the potential buyer or tenant than those with better grading.