The National Research Programme for Global Air Pollution and Climate Change commissioned us to investigate whether the different ways in which households use energy for their domestic activities can be divided into patterns that could be regarded as lifestyles. At the same time we investigated whether such lifestyles would offer suitable bases for promoting energy saving forms of domestic consumption. The most important conclusion of the research is that one's lifestyle is important in the way in which energy is used for domestic purposes, and the underlying reasons for this. For many people, motives such as efficiency, time savings, health and social contact appear to play an important role. Attempts to reduce energy consumption must take account of the fact that these 'advantages' of domestic energy use must be maintained.