This International Standard sets out ways of expressing the overall energy performance of a building. This includes an overall numerical energy performance indicator and classes against benchmarks. It also includes ways of expressing energy performance requirements. Furthermore, methods for energy performance certification of buildings are included. This standard provides different (alternative) options, including both absolute indicators, such as energy performance per unit of floor area, and relative indicators, such as energy performance compared to the energy performance of a reference building (notional building approach). The rationale for each option, examples and all informative procedures will be provided in the accompanying technical report (EN ISO/TR 52003-2). This International Standard does not include numerical indicators at system or component level (these will be covered by EN ISO 52017-1 (building fabric and building elements) and similar standards on technical building systems. Voting in paralell with ISO, with ISO lead under Vienna Agreement.