I Indoor ndoor and and Built uilt Environment Special Issue – Fuel Poverty Mixing methods, maximising results: Use of mixed methods research to investigate policy solutions for fuel poverty and energy vulnerability Kimberley O’Sullivan and Philippa Howden-Chapman Abstract Mixed methods research is particularly well suited to investigate complex policy problems such as fuel poverty, which require empirical evidence to inform intersectoral solutions. This paper draws on our theory-driven interdisciplinary studies in the built environment to analyse the outcomes and possible policy pathways to address fuel poverty. Insights are drawn from our own fuel poverty research using community-based mixed methods research to explore both the outcomes of interventions and the behaviour of people in indoor environments. Finally, we suggest future directions for mixed methods policy-focused fuel poverty research to leverage growing national and international political interest and policy recognition of the problem. Keywords Energy poverty, Mixed methods, Research translation, Energy policy, Public health, Multidisciplinary, Retrofit Accepted: 6 April 2017 Introduction Solving the complex problem of fuel poverty, increas- ingly understood to include broad definitions of energy vulnerability, 12 necessitates the development and use of intersectoral policy solutions spanning siloed govern- ment departments and ministries that traditionally hold primary responsibility for relevant policy areas, such as energy, housing, building, and health. Fuel pov- erty, like most public policies, requires a strong case to be made that each of these departments has something to gain by contributing to the development and imple- mentation of a coordinated policy, which delivers co- benefits to all, 3 regardless of the leading department. Mixed methods research offers opportunities for drawing on varied sources of evidence to better capture the multi-dimensional experiences and outcomes, as well as antecedents, of fuel poverty within communities and potential solutions to resolve household energy vulnerability. Furthermore, mixed method research approaches are typically born of pragmatist and trans- formative epistemologies. These understandings are ideal for inter-disciplinary, multi-disciplinary and indeed transdisciplinary research investigations, which include researchers from different disciplinary back- grounds to produce new frameworks and research methods. 4 We describe practical examples of how to create the evidence base to underpin the translation of research to policy. We site fuel poverty as a public health problem within the social, cultural and economic structural determinants of health and draw on relevant literature to provide suggestions for ongoing engage- ment to achieve research translation. We go on to out- line the advantages and disadvantages of mixed methods research to achieve these goals. Finally, we He Kainga Oranga/Housing and Health Research Programme, Department of Public Health, University of Otago, Wellington, New Zealand Corresponding author: Kimberley O’Sullivan, University of Otago, Wellington, PO Box 7343, Wellington 6242, New Zealand. Email: kimberley.osullivan@otago.ac.nz Indoor and Built Environment 0(0) 1–9 ! The Author(s) 2017 Reprints and permissions: sagepub.co.uk/ journalsPermissions.nav DOI: 10.1177/1420326X17707327 journals.sagepub.com/home/ibe