Sarra Kasri: Architecture as an indicator of risk, at the expense of urban timeframes

The focus on disasters has confined most research into risk to the history of specific events. Moving beyond this approach and following in the footsteps of Fernand Braudel, our thesis is rooted in the history of the long term, as evidenced by ‘the morphological trajectory of the urban landscape’ and ‘the trajectories of architecture’. In other words, we shall draw on the traces of the history of territorial morphology to understand architecture as a process of stabilising an inhabited and meaningful materiality anchored in socio-technical networks. Our hypothesis is that the hybridisation of architecture enables us to identify the fluidity of these historical strata (in the sense of Marcel Roncayolo) by revealing situations of risk and their resolution. The thesis aims to discuss this hypothesis through a historical approach, grounded in architectural theory and socio-geographical references. The ultimate objective is to propose an innovative approach to architecture by demonstrating that it can serve as a revealer of the unstable nature and volatile dimensions of risk.

The historic centre of Tunis forms the basis of our empirical approach. This choice is justified primarily by the fact that it is an area exposed to risks, yet one that has not recently experienced any catastrophic events. Our analysis is based on the study of three architectural typologies representative of Tunis’s history: a traditional house, a European-style building and a self-built dwelling. These enable us to identify three levels of understanding of the dynamics of risk generation in relation to scientific, economic, social and even ecological contexts: 1/ the crystallisation of risks through technical hybridisation via risky attachments, 2/ the amplification of risks through the hybridisation of uses and standards, 3/ the fluctuation of risk situations due to their recalcitrant nature. By situating itself within the paradigm of the extensive roots of risk, the thesis highlights its generative processes through the prism of urban temporalities and architectural hybridisations. It reveals the importance of documenting the systems of belief and knowledge specific to each territory. The loss of memory regarding natural disasters, coupled with the erosion and alienation of knowledge concerning hazards, social norms, architectural materialities and modes of habitation, are the triggering factors for risk situations. Ultimately, this thesis proposes the construction of an architectural understanding of risk based on an indexical logic, which forms part of a reconstruction of historical, context-specific knowledge reactivated by lessons learnt.