The global population living in cities is expected to reach nearly 70% by 2050. This trend in urbanisation will require massive amounts of infrastructure to be built from concrete and other natural and manufactured materials. In the second episode of our miniseries on the circular economy, we explore the business case for circular resource flows - such as concrete, wood, and glass - in the construction and building sector. We meet Associate Professor Yuliya Voytenko Palgan, who discusses why cities are so important in addressing our sustainability challenges. Then, we invite PhD Candidate Julia Nussholz as well as recent IIIEE Master’s graduate Felicia Gustafsson to join us to discuss their research. We explore examples of closing and slowing resource loops in the construction industry as well as consider how to design circular business models that facilitate customer acceptance. But, are businesses doing enough? And, what is the role of policymakers to promote a circular economy that truly delivers on its sustainability promises?