Footprint 30 explores the work of French philosopher of technology Bernard Stiegler (1952–2020) to critically rethink the built environment in terms of a constructed yet emergent existential niche. Foremost concerned with technics, the purchase of Stiegler’s thinking and conceptual apparatus is to be found in the proposition of a novel theoretico-methodological turn towards epiphylogenetic processes. Yet to be embraced by discourses on architectural and cultural technologies, the notion of epiphylogenesis implies a kind of recursive path-dependent co-evolution of living systems with non-living means, especially technics. This sympoietic vision – of how culture-shaping technics and technical ensembles like cities (trans)form us – urges us to rethink how environments re-shape ontogenetic processes. The contributions to the issue call for a radical recasting of the architectural discipline by reconsidering the ‘what’ of technicity as constitutive of a (post)human ‘who’.