Decay' of Materials in Architecture

How do different societies embrace the ‘decay’ of materials in architecture? This essay dissects this question by revealing how materiality plays a larger role – beyond its presumed role for structural and environmental performance – in shaping sensory and tactile connections between architecture and the community. The term ‘decay’ will be used to describe the gradual process of a material losing its functional integrity – such as the erosion of mud by rain or the rotting of timber – through the passage of time and environmental exposure. Drawing from material culture theory and phenomenological perspectives, particularly the writings of Juhani Pallasmaa, the study conducts a comparative analysis of the Great Mosque of Djenné in Mali and traditional Japanese minka houses. Material decay is not simply a passive process of architectural deterioration but active inscriptions of time, craftmanship and cultural continuity. In Djenné, the erosion of mud walls by seasonal rains leads to the annual Crepissage, a communal ritual of replastering the mosque, where human hands, material surface and climatic rhythms engage in a cyclical act of renewal. Similarly, in the Japanese minka, timber is intentionally allowed to age and rot as part of a spiritual ecology that honours impermanence, aligning architecture with natural cycles and the aesthetic of wabi-sabi. Contrasting these case studies with modern architecture – built using materials like glass and steel which resist erosion – the essay questions what is lost when the surface material is sealed off from ecological and human contact. Can architecture that avoids weathering and ageing still hold the intimate imprints of bodies, climates and histories? By reconsidering ‘decay’ as a medium of material contact and transformation, this study repositions architecture not as a static object, but as a responsive ecology – one that is shaped by, and shapes in return, the more-than-human forces that act upon it.