Reducing energy demand and increasing energy efficiency are two major objectives that numerous national and international programs, such as the EU 20-20-20 targets, seek to achieve in the ongoing transformation of energy systems. Despite the predominately socio-economic nature of energy demand, such interdisciplinary viewpoints – albeit on the rise – are still the minority within energy-related research. In this paper, we develop an applied approach to support interdisciplinary research focusing on a common research objective which examines and clarifies the three questions: ‘What’, ‘Why’ and ‘How’. We test the capability of the approach by performing an exemplary review of energy demand both from an economics and a social-science perspective.