Exchange of experience between researchers and practitioners is important for arriving at new knowledge that is translatable into practice and at the same time endures in science. This notion has been central in CHANGING BEHAVIOUR, a project aimed at a better understanding of why energy demand-side management (DSM) programmes succeed or fail. Generally, there is a growing tradition of evaluation that encompasses the co-construction of programmes, technology and context. Nevertheless, most current research and evaluation in this particular area focuses solely on the influence of programme characteristics while overlooking contextual factors and transdisciplinary integration. This paper presents the outcomes of theoretical and empirical work involving new insights regarding the crucial conditions for successful energy DSM programmes. In addition, we demonstrate the usefulness of an Action Research methodology that aims to explicitly promote social change though transdisciplinary collaboration between researchers and practitioners. We conclude that a conceptualisation of energy behavioural change as nested within and interacting with broader social processes differs from existing models that place individual change processes at the centre of attention. The toolbox we developed for and with practitioners (involved in designing and implementing energy demand-side programmes) differs accordingly, among others in that it is context-sensitive. (C) 2010 Elsevier Ltd. All rights reserved.