The main objective of the study was to provide insight in the drivingforces for energy conservation and their relation with conservation policy instruments and to investigate the present and future situation regarding energy conservation in different countries in terms of differences and common challenges. The results give rise to the following recommendations regarding national and European Union (EU) policies. Research and Development policies should particularly pay attention to the energy services and branches with a relatively small technical energy conservation potential available at the moment, in particular those for which the share in total consumption is large or is projected to grow. In households, energy services such as drying, miscellaneous electric household appliances (audio-video, hobby, personal care, sleeping etc.) and washing should have priority in order to reduce households energy consumption in the long run. For the manufacturing sector, the technical saving potential in the subsectors Chemicals, Metal products and Building materials should be enlarged. Feedstocks comprise a substantial share of the industrial energy consumption. Research is required on complex integrated process improvements, substitution of materials, possibilities for recycling and utilisation of residuals and waste in industrial processes. Energy conservation policy should close the gap between realised energy savings and technically available potential, prioritising those energy services and manufacturing branches which require a large share of the energy consumption, now or in the future. In households, for hot water, cooking and cooling a large gap between technical potential and realisation is calculated. Furthermore, heating is important since it covers a large share. This 'efficiency gap' is smaller in the manufacturing sector where the investors are more rational. Therefore R and D policies on the development of new technologies are more important for this sector. The case studies indicate that for households the availability of profitable saving technologies is not an important barrier for energy conservation. Much more important barriers are the competitive disadvantages of new entrants, bifurcation effects due to low replacement rates, strong competition and decreasing effectiveness of new technologies after substantial savings. Therefore, the savings induced by general financial and behavioural instruments are limited, as relative competitive advantages are not addressed. Hence, most impact can be expected from combinations of instruments addressing different barriers simultaneously, policies focusing on specific technologies and from regulation which may overrule existing barriers. 17 refs.