Porous Palimpsests. Natural and artificial boundaries in a post-industrial landscape / Palinsesti porosi. I confini tra naturale e artificiale in un paesaggio post-industriale

Urban porosity has become an influential concept in urban design discourse, used to describe spatial openness, permeability, and the capacity to accommodate change. Yet it often remains a metaphor lacking operational tools for analysis and design. This paper proposes an Urban Porosity Matrix (UPM), a five-dimensional approach that interprets porosity through spatial, visual, socio-functional, ecological, and temporal conditions. The matrix is explored through the post-industrial landscape of Parco Dora in Turin, interpreted as a porous palimpsest where industrial relics, water, vegetation, and public uses interact. In this coexistence, boundaries between natural and artificial systems become blurred, echoing the theme of 'supernatural' explored in this issue. The UPM offers a framework for reading and designing porous urban landscapes.