The Energy Performance of Buildings Directive (EPBD) requires EU member states to establish a methodology for calculating the energy performance of buildings within a framework that includes the effect of active and passive solar systems as well as other characteristics of buildings and their installed energy systems. Member states must also implement regulations based on this methodology, aimed at reducing the energy use of buildings by promoting both energy saving measures and a wider use of renewable energy sources. To facilitate the implementation of the Directive the European Community mandated the CEN to draft a series of standards that provide methods to assess (by measurement or calculation) the energy performance of buildings, including existing buildings and those in the design stage, ways to express energy performance requirements, and a certification procedure. This paper describes the global methodology proposed for building energy certification and presents the content of the main standards.