Energy poverty is becoming a main challenge of the European welfare systems and beyond, abounding on the inequalities derived from living conditions and social determinants, with a direct and negative impact on health and wellbeing, mainly in urban contexts. Health problems attributable to energy poverty include respiratory diseases, heart attacks, stroke and mental disorders (stress, anxiety, depression), but also acute health issues, such as hypothermia, injuries or influenza. The complex nature of this recently identified phenomenon requires a comprehensive analysis of the problem and its solution from a multidimensional approach, which should involve environmental, political, social, regulatory and psychological issues, thus involving other Social Determinants of Health and health inequalities. Urban policies and initiatives might respond very efficiently to energy poverty and their effects on the citizens wellbeing and health, by providing evidence-based interventions covering different angles of the challenges, including complementary actions covering individual (behavioural) but also social-political actions (regulations, urban planning) that include health in all policies. Based on the socio ecological model and on the realist evaluation approach, WELLBASED will design, implement and evaluate a comprehensive urban programme to reduce energy poverty and their effects on the citizens health and wellbeing, built on evidence-based approaches in 6 different pilot cities, representing different urban realities but also a diverse range of welfare and healthcare models. The project’s multidisciplinary consortium, made up of 19 partners from 10 countries, has been built to guarantee the full coverage of the scientific, clinical, social, and environmental competencies, and to gather the viewpoint of different communities and actors necessary to develop, test and evaluate the interventions related to WELLBASED in order to maximize its chances of success. WELLBASED is a part of the European cluster on urban health.