In Material Matters, architect Thomas Rau and Sabine Oberhuber economist , co-founders of Madaster, make a deceptively simple argument: our planet is a closed system, and every material we extract, use once, and discard is a decision we are making against our own future. Their proposition is radical but practical — buildings should be designed as material banks, products offered as services, and manufacturers made custodians of materials rather than sellers of objects. Waste, in this model, is not an inevitability. It is a design failure.
Construction is where this argument hits hardest. Buildings lock up enormous quantities of steel, concrete, timber, aluminium, copper, and rare materials — often for decades — with no system to track them, recover them, or reintroduce them into the supply chain. The material passport, which Rau helped pioneer through Madaster, is one answer: a digital record that gives every component an identity, a history, and a future. Without it, urban mining remains guesswork.
The geopolitical context makes this urgent in a way it wasn’t five years ago. Europe depends on imported raw materials — many of them from politically unstable or strategically contested regions. The Critical Raw Materials Act is a direct response to that vulnerability. Treating the existing building stock as a material reserve is not just an environmental strategy. It is an industrial sovereignty strategy.
So: how are you approaching material strategy on your projects? Are buildings in your practice already being designed or documented as material banks? And what would it take — technically, contractually, culturally — to make that the default?