BACKGROUND: There is great diversity within the group of old people and the socioeconomic resources of income, formal education and occupational status are unevenly distributed. A low socioeconomic status means high risks for health and poverty, disadvantageous housing situations and fewer opportunities for social participation. AIM/QUESTION: In social space-oriented approaches, the possibilities for strengthening the social participation of marginalized older people still appear to be limited. What should a professional concept look like in order to make weak interests heard? CONCEPT: The concept of social space development and social space organization as an instrument for professional promotion of highlighting and realization of own and mutual interests is presented. It was developed in social work in the context of participatory social space research and examples are presented in this article. Social space development aims to enable groups of people who are connected by mutual interests to meet not only in special places created for the care of older people or community work but also in public places in the spaces that are important for themselves and to appropriate spaces for the representation of their own life designs. In the second step, different interest groups are brought into a moderated negotiation process. Social space organization describes how professional work provides access to the resources of the welfare system for the realization of the interests brought forth in the processes of social space development.