Helmut Haberl is a professor at the Institute of Social Ecology, University of Natural Resources and Life Sciences, in Vienna (BOKU). In his presentation he focuses on the role of the material stock of buildings and infrastructure, and he explains how social metabolism can be understood as a stock-flow phenomenon and how this is closely connected to services provision. He also covers the idea of eco-efficiency, noting how decoupling commensurate with ambitious climate targets has never been observed so far.