Utilising energy efficiency to lower energy demand in buildings is a key policy goal of the European Commission. This paper presents the results of bottom-up modelling to elucidate the impact of energy efficiency on the EU building stock up to 2050 under three different scenarios. The modelling is performed for eight individual EU countries and a ninth hypothetical entity that represents the remaining nineteen EU countries. The scenarios highlight the roles of different levels of efficiency improvements in the context of increasing floor area and the demand for energy services. From the results it can be concluded that the EC 2020 goals for primary energy savings can be met by focussing on a combination of minimum efficiency construction standards, improved conversion efficiency standards for final energy to useful energy, and a >= 2% annual improvement in end-use efficiency applied at the useful energy level. A comparison of the results obtained in the present study for Spain with the estimates of savings documented in the Spanish Energy Efficiency Action Plan indicate that the plan could lead to the closing of the energy efficiency gap for buildings in that country by 2020. (c) 2013 Elsevier Ltd. All rights reserved.