The Urban Mining and Recycling (UMAR) Experimental Unit is one of the units at the NEST research building on the campus of the Swiss Federal Laboratories for Materials Science and Technology (Empa) in Dübendorf, Switzerland. The building design created by Werner Sobek with Dirk E. Hebel and Felix Heisel demonstrates how a responsible approach to dealing with our natural resources can go hand in hand with appealing architectural form. The project is underpinned by the proposition that all the resources required to construct a building must be fully reusable, recyclable or compostable. This places life-cycle thinking at the forefront of the design: Instead of merely using and subsequently disposing of resources, they are borrowed from their technical and biological cycles for a certain amount of time before being put back into circulation once again. Such an approach makes reusing and repurposing materials just as important as recycling and upcycling them (both at a systemic and a molecular/biological level, e.g. via melting or composting). This conceptual emphasis means that UMAR functions simultaneously as a material laboratory and a temporary material storage.