Is the concept of urban metabolism useful for planning practice?

In the last decades, the concept of urban metabolism has been a fundamental topic of the debate on cities. From the overall definition of the concept to the specific measurement of its different components, urban metabolism has been discussed in an increasing number of papers and books, particularly after the 2000s. While it is widely assumed that planning would benefit from the incorporation of the concept, there are few scientific outputs with potential for application into day-to-day practice or, indeed, reviews on that practice as part of an eventual process of integration. The paper tries to address this gap. After discussing the concept, its main components and its applicability into practice, the paper offers a review of day-to-day planning in one particular country – Portugal. Based on this insight on research and practice, it outlines a number of principles for evaluating urban metabolism. It is argued that urban metabolism should be evaluated within planning practice, different metabolic components should be assessed at different scales, the measurement of these components should be selective and balance complexity and pragmatism, and that land should be reinforced within the metabolic framework and be acknowledged as a key element in the linkage between research and practice.