Engineers often conduct energy audits in buildings in use with the aim of improving the energy consumption of the facilities. The problem with this traditional approach is that the audits take place at a given instant in time. Subsequently, it is necessary to track the amount of energy continuously consumed in buildings in order to deal with an energy efficiency problem. This paper proposes the continuous assessment of energy efficiency in buildings using different energy rating factors. These factors have already been presented in other works by the authors, and the usefulness of these factors for assessing the energy performance of buildings and identifying wasted energy has been proven. This article presents the results of applying the methodology in 55 buildings located on the Universitat Politecnica de Valencia campus during an entire year. (C) 2012 Elsevier B.V. All rights reserved.