Stacking risk: The growing seismic vulnerability of self-built housing in Mexican colonias

Despite decades of scholarship on informality and housing precarity in Latin America, seismic risk in self-built urban settlements remains underexplored in architectural and urban discourse. This paper critically examines the construction dynamics of colonias —informal settlements on the peripheries of Mexican cities—arguing that current practices not only reproduce structural vulnerability but may actively intensify seismic risk. Drawing on field observations and structural screening, the paper reflects on the persistence of unreinforced masonry, the prevalence of the “inverted pyramid” form, and the socio-economic logic of incremental construction, where vertical expansion is tied to both status and survival. These are not merely technical oversights, but culturally embedded practices shaped by structural inequality and governance gaps. While seismic engineering has advanced, its frameworks often exclude the realities of informal housing. The paper calls for a broader architectural response: one that confronts the ethical implications of inaction, challenges normative building assumptions, and advocates for grounded, context-sensitive interventions. Seismic resilience in informal settlements will not emerge from top-down regulation alone, but from rethinking how risk, agency, and material practices intersect in the making of urban peripheries.