Adaptive reuse is seen as a key to sustainability and more successful decarbonization. This panel examines the case for sufficiency through the use of conversions, renovation and adaptive reuse—collectively, umbau in German—with a multidisciplinary panel representing the various areas of expertise needed for effective transformations of existing buildings and places. Sustainability is cast as a structural quality in an overarching sense—systematically gauging the effects of planning decisions on project lifecycle overall. As seen in the companion exhibition, a selection of gmp’s 60-plus umbau projects demonstrate how structures can be flexibly used, reused, expanded, and sustainably fortified.