This doctoral thesis deals with the type of architecture that materializes when age-related problems become a long-term condition (LTC) and gradually restrain the individual’s ability to perform activities in daily life (ADL). Their life situation necessitates a support from relatives or municipal eldercare staff in order for them to continue to participate in everyday living. In addition, the architectural space requires a close adjustment to the personal panorama of cognitive or functional impairments. The habitat can be a flat appropriated many years previously or in a residential care home for dependent and frail seniors. Architecture for ageing with dependency demonstrates how space can be used either to affirm or oppress the older person’s attempts to maintain an independent life style. By use of design theory, case study methodology and a heterogeneous research strategy, this study uses a threefold approach—a retrospective, a contemporaneous, and a future-oriented approach—to explore frail older people’s interaction with the architectural space of residential care homes. This has resulted in seven papers that focus on aspects of these human interactions with the built environment. Based on twelve exemplary models, the research paper I concludes that national guidelines result in a homelike, a hotel-like or a hospital-like environment. Research paper II is a retrospective study that examines the use of architecture competitions as a socio-political instrument to define architectural guidelines. Research paper III focuses on dependent seniors’ spatial appropriation of the communally shared space of a ward in a residential care home. Research paper IV employs two environmental assessment methods from the architecture profession and gerontological research (TESS-NH) in order to evaluate the use of interior colouring when refurbishing two residential care homes while the residents remained in place. Research paper V displays a municipal organizer’s considerations to opt for an architecture competition as a means of renewing architecture for the ageing population. Research paper VI examines competition documentation of three municipal architecture competitions organized during the period of 2006 to 2009. Research paper VII, the final study, explores notions concerning the appropriate space for ageing found among a group of municipal representatives, and people from organizations defending older people’s right. It supplies a model for understanding the appropriate space for ageing. This study illustrates the absence of older people with frailties in the public discussion about appropriate architecture for ageing. During the 20th century, the multi-dimensional idea of an architectural space with a homelike appearance has been used to contrast the negatively charged opposite—the complete and austere institution. The overarching conclusion of this study is that architecture for dependent and frail seniors constitutes a particular type of built space that requires an extended dialogue involving dependent seniors, architects, building contractors and care planners in order to conceive appropriate architecture for the ageing society. / QC 20110921