This paper argues that the moderate success of policies aiming to stimulate the uptake of Sustainable Energy Systems (SES) in the domestic sector is grounded in a poor understanding of the ‘consumer’. The predominant economic approach behind most policies assumes that improving the cost-benefit ratio of technologies via grants and subsidies and providing sufficient information will automatically incentivise householders’ to invest into SES. Yet, policymakers often neglect behavioural determinants such as attitudes, social norms or personal capabilities. Drawing on key findings from the economics, technology and behavioural literature, this paper proposes an integrated model to identify behavioural and contextual influences of SES adoption. It further highlights relationships between them and serves as a starting point to empirically research SES adoption, ultimately providing pragmatic answers to complex policy questions.