Across the world, countless buildings stand vacant: abandoned, underused, or deemed obsolete, wasting resources and accelerating urban decay. The act of demolition, often seen as progress, carries a high environmental cost, producing waste and carbon emissions. INDESEM.25 takes this condition as a starting point, reframing obsolescence not as an end, but as a catalyst for transformation.

Each year, the International Design Seminar brings together students and leading architectural voices in Delft for a week of lectures, workshops, and design experimentation. The 2025 edition challenges the prevailing culture of demolition, questioning why existing structures are so readily discarded instead of reimagined.

BC architects studies & materials was invited to contribute and Ludovica Cassina, former project leader at BC, explored the transformation of resources into experiential, ecology-driven structures, grounded in the use of local materials within a 50-kilometre radius. During her workshop, around eighty students investigated regional resources of sand, clay, and plant fibres, testing their potential through the creation of plaster samples.