The Energy Performance Building Directive (Directive 2002/91/EC) introduced the compulsory energy certification of buildings in the EU from 2006 and it has played a key role in the common policy to monitor and reduce energy consumption. In order to assess the experience gained in this field in Europe overall, and in particular against the highly diverse settings of the different European nations, this paper examines the extent to which the Directive has been implemented by the 27 EU Member States. This is done via a comparative analysis assisted by two different indicators: of uniformity and of excellence. The measure of uniformity makes it possible to assess the degree of harmony of the individual Member States with regard to the parameters laid down by the European Commission, while the measure of excellence allows the Member States to be appraised and the "best" performers to be identified, i.e. the leaders as regards energy certification of buildings. The analysis conducted reveals how varied, the situation regarding energy certification in each country is in terms of implementation and scope of application and it also reveals that most countries are still at a halfway stage towards achieving excellence. (C) 2010 Elsevier Ltd. All rights reserved.