Casablanca was long time perceived as laboratory for European architects to experiment with modernist mass housing. Yet, the spatial structure has since then been considerably transformed and appropriated by the inhabitants to respond to the requirements and aspirations of everyday life. The neighbourhood Hay Hassani has experienced substantial change since its construction in 1958-62, initiated by its residents. This paper aims to explore the inhabitants’ underlying reasons and means to adapt their dwellings, and further to provide perspectives into the logics behind these bottom-up, informal transformations. Applying phronetic planning research, an empirical case study has been carried out in Hay Hassani, which provides detailed narratives of the ways in which power and values are at work and with what consequences to whom. The findings indicate that multiple economic, socio-demographic, and cultural aspects are decisive dynamics that trigger the motivation or urge to adapt the original modernist architecture. While identifying the (f)actors of importance and drawing their power relations, the research reveals that because of reduced architectural, economic , institutional-political, and social barriers the inhabitants have been able to transform their built environment significantly. The present study highlights that questions of values, judgement, and power relations are central to understand and deal with the bottom-up transformation processes in the spatial development. / Migration as Inspiration (The Netherlands)