The Swedish Social Services Act (SFS 2001:453) stipulates since 1982 that the municipal Social Committee should become well acquainted with the living conditions in the municipality. They should also participate in urban planning, and in cooperation with other public bodies, organizations, associations and individuals promote good living environments in the municipality. The development, planning and design of good living environments for older people is an endeavour of great complexity that demands collaboration between many actors. Housing and care for older people is an important area in which social servicesand urban planning could benefit from collaboration. Planning for older people has recently been indicated as urgent and necessary, especially in the light of changed demography in which the proportion of older people is increasing. A built environment that accommodates older people’s everyday needs embraces issues such as age-friendliness, care, socio-spatial inequality, inclusion, and innovation. This research program, CollAge, investigates cross-sectoral collaboration in Swedish municipalities between social eldercare, urban planning and Senior Citizens’ Councils as regards housing and care. With diverse qualitative methodologies the multidisciplinary team of scholars in social work, architecture and urban planning explore how eldercare interventions and services are managed and understood in municipal urban planning and development, and how older people’s preferences can contribute to improved quality of care in social services and housing provision. The ultimate aim of the programme is to develop a methodological tool – CollAge – to support, facilitate and structure collaboration between the three actors.