This thesis focuses on the design of closed cohabitation units meant to accommodate population groups that require special care, on the design parameters with regard to the provided care and the empirical way that humans live, coexist and are influenced by a built environment in conditions of social restriction. More specifically, this thesis discusses how people can coexist and interact, both with each other and with the surrounding community, inside the spaces of the orphanage and nursing home, as building structures within which special treatment/care can be provided. In this context, the city of Volos' orphanage and nursing home are housed together in a diverse and pluralistic project, with care provision being the principal factor.

 The goal of this study is to investigate the aspects of collective housing with regard to specific age groups, the characteristics of each group and the necessities for care, the way these necessities are expressed spatially and the typological characteristics that facilitate the residents' both individual living and symbiosis.

 As the most important factor in the functionality and final configuration of the design of any building structure is intended to be the resident himself, thus the proposed configuration is characterized as "open" and with the ability to easily transform itself, in order to support a diverse range of operations and everyday activities. The study of architectural design in collective housing is particularly useful and a fluctuating concept in the context of Greek society. From this fluctuation a new type of care building is born, aiming to host a mixture of age groups (younger and older people) with shared activities but also interaction with their social environment (the neighborhood and the city of Volos).