On 20 June 2013, the Commission published a study on "Energy performance certificates in buildings and their impact on transaction prices and rents in selected EU countries". The study shows a positive impact of the Energy Performance Certificate under the Energy Performance of Buildings Directive (Directive 2010/31/EU) on sales and rental prices indicating that better energy efficiency is rewarded in the market. In one of the first studies of its kind to include an analysis of residential markets in Europe, it was found that higher energy ratings result in substantially higher sales or rental values of buildings on average in most of the Member States that were analyzed.
The Spanish market is not included in this study, as the obligation to hold an energy certificate has been recently approved and there is not yet enough data to assess its impact in the real state market. However, the conclusions of the study for neighbor countries such as France revealed that an improvement of the household energy efficiency leads to a 4% increase of its market value.