15 INTRODUCTION ON TERRITORIAL METABOLISM Marco Ranzato and Geoffrey Grulois The concepts of urban metabolism are today challenging urbanism practice and theory (e.g., Kennedy et al., 2011; van Bueren et al., 2012; Ibanez and Katsikis, 2014; Sijmons, 2014). Urban plans and design research from metabolic and ecosystem perspectives are promoted by administrations both national (for instance, the Ministry of Urban Development and the Strategic Office of the Prime Minister of Albania, the UK government’s Foresight Future of Cities Project) and urban (see, for example, Geneva, Antwerp). As the shift from linear to circular production-consumption patterns seems to be decisive for reducing the external influences on our urban environments and for meeting stricter environmental targets (see, for instance, Europe 2020 targets), the search for circular urban metabolism and efficient resource use has become imperative for our metropolitan areas. This section of the book takes this as its starting point and discusses the concept of urban metabolism in relation to urbanism. We call into question the role of urbanism in the search for a more circular urban metabolism and resourceefficient metropolitan regions. We propose to expand on this issue by looking at the relation between design, urban metabolism, and an ecosystem approach through five original contributions from instructors and experts involved in the strategic partnership between Metropolitan E-studio and Related Design Studios (2015–2017). These essays offer diverse considerations supporting our intention to propose three different standpoints on these issues.