Attempts to improve the energy performance in the residential sector mainly pay attention to new buildings. However, a decrease in energy consumption and greenhouse gas emissions will never occur if nothing is done to improve the existing energy devouring housing stock. This paper discusses economically feasible ways and means to choose between insulation measures, better glazing, installation measures and renewable energy systems such as solar collectors and PV cells. Finally a logical hierarchy of energy-saving measures is deduced from the results. (c) 2004 Elsevier B.V. All rights reserved.