The increasing European Union legislation on building and energy services and widespread adaptation on energy labeling and certification provides a unique opportunity to analyse characteristics of building stock at micro and macro level. Thus there is a need to handle large database in order to extract trends and performance statistics. The European DISPLAY campaign is a voluntary scheme aimed at encouraging local authorities to publicly display the energy and environmental performances of their public buildings. The underlying hope is that participating in the DISPLAY certification campaign will lead to significant improvements in the energy performance of municipal buildings. This paper addresses the issue of energy certification through presenting trends in building ratings for energy, CO2 and water. Paper also gives glimpse of trend for performance of buildings using simple methodology. Encouragingly the clear trend over time is that there has been an increase in the number of A rated energy certificates, and steady decrease in the number of both F and C, rated energy certificates. However, the emphasis of this paper will be on the improvements and deteriorations experienced by specific buildings. Having assigned a numerical value to each 'grade', method has been identified to measure the building energy performance. (C) 2011 Elsevier B.V. All rights reserved.