SUSTAINWELL addresses the long-term socio-economic impact of population ageing on European society. SUSTAINWELL aims will be to identify: (i) opportunities arising from longer and healthy life expectancy and in general from the silver economy; (ii) resilient responses from individuals and households (in market and non-market outcomes) and from other actors in society facing the challenges posed by ageing; (iii) the impact of ageing on inequality (both within and between generations), knowing that social cohesion is crucial to face the ageing challenge; (iv) gender and lifecycle balanced policies helping the sandwich-generation to sustain baby-boomers entering retirement, without decreasing fertility nor investment in education. Particular attention will be devoted to the role of job design to foster intergenerational complementarities in the labour market. To better understand the benefits of living longer, SUSTAINWELL will take a holistic perspective by: a) investigating the behavioural reactions in key lifetime decisions along the lifecycle (education, skills, fertility, work effort, home production, savings and retirement) and the decision process itself leading to prosocial behaviour; and b) accounting for the three ways to provide welbeing along the lifecycle (market, family and welfare state). Both dimensions will be analyzed by extending the National Transfer Accounts method (using comparable EU datasets) to be incorporated as inputs in a dynamic microsimulation comparative model quantifying the future of ageing societies. SUSTAINWELL will take a new multidisciplinary approach in different basic (Neuroscience) and social sciences (Economics, Demographics, Sociology and Political Science). SUSTAINWELL’s results will be pursued in permanent contact with stakeholders, to deliver knowledge and evidence-based policy measures by applying a participatory design and co-creation activities.