In this study the Italian and Spanish national regulations related to the transposition of Directive 2002/91/EC on energy efficiency in buildings are compared. Three typical buildings were selected for the comparison: a semidetached house, an independent house and an apartment. These buildings were located in different climatic zones of each country and simulated with different orientations. The energy standards in Italy, Decree 192/05, valid for years 2006, 2008 and 2010, and in Spain, the Codigo Tecnico de Edificacion, were also compared with the German standard called Passivhaus. The contribution to total energy demand of winter and summer energy demands was evaluated, along with a statistical distribution of the consumptions for the various climatic zones and orientations. The increase in the energy consumption limitations in Italy over the years was also analysed. The results show that the least restrictive Italian regulation, i.e. the one valid for the year 2006, is more restrictive than the Spanish regulation. (C) 2008 Elsevier B.V. All rights reserved.