Informal housing adaptation to sociocultural and environmental conditions: Peri-urban dwelling practices under rapid urbanization in Dar es Salaam, Tanzania

Although more than half of the urban population in sub-Saharan Africa reside in informal housing, knowledge about the material and spatial characteristics of such dwellings remains limited. This study examines informal housing practices in the Mabibo neighborhood of Dar es Salaam, Tanzania, using detailed surveys of the built environment and household data collection to investigate how dwellings are adapted to contextual conditions. Sociocultural adaptation strategies include spatial configurations to accommodate complex household structures, where extended families and tenants often reside in separate sub-units within the same plot, driving emergence of new courtyard housing typologies typified by built environment densification and increasing rental accommodation. Economic adaptation strategies include integration of income-generating functions in dwellings such as shops and rental units, incremental dwelling expansion based on available resources, and subdivision of plots to accommodate additional households. The study documents evolving construction practices with traditional housing being replaced by dwellings built from industrial materials and repurposed waste. Environmental adaptation strategies include raised floors to mitigate flooding, window screening to reduce exposure to mosquito-borne diseases, and suspended ceilings reported by residents as improving indoor thermal comfort. These findings show how peri-urban informal housing practices in rapidly urbanizing African cities evolve through adaptation to contextual conditions, such as land scarcity, constrained household economies, and availability of industrial construction materials linked to global supply chains.