The vast majority of city planning literature on informal occupations has focused on how residents occupy vacant and peripheral land, developing informal structures to address their basic needs. A smaller body of work, but one with much purchase in South Africa, explores the informal occupation of existing formal structures and how residents infuse these emergent places with social and political meaning. Across this work, occupations represent a dominant mode of city-building in the Global South. Contributing to this debate on city-making and occupations, this paper departs from an unusual case of South African occupation. We explore how displaced people have occupied a multi-storey vacant hospital building situated close to Cape Town’s city centre. Using documentary photography and interviews with residents, we argue that this occupation reflects a logic of ‘retrofit city-making’. We show that, through processes of repairing, repurposing, and renovating, dwellers have retrofit an institutional building, previously designed by the state for a very different use, to meet their needs and desires. As cities become more densely built and vacant land more peripheral or scarce, the retrofit of underutilised buildings, particularly through bottom-up actions such as occupation, will become an increasingly important mode of urban development. Not only are the practices of material transformation useful to understand, so too are the ways in which occupations reflect significantly more than simply survivalist strategies, but also care and meaning-making.