Energy consumption patterns are a complex technical and social phenomenon and thus to fully understand this phenomenon, it must be viewed from both engineering and social science perspectives. Over the last 20-30 years, energy research within each of these disciplines has progressed relatively independently, however, it is now being realized that in order for further development to take place these two perspectives must be integrated to form a single and coherent view of energy use. This paper proposes an integrated descriptive framework for energy use and behaviour, based on systems theory. This framework begins to indicate where the various models and theories from both the engineering and social sciences relate and thus is a first step towards a more integrated and coherent view of energy use.