What does urban metabolism refer to in planning?

• A. A method of measuring municipal budgets.
• B. A focus on the metabolism of individuals in the city.
• C. The city as a system of flows of energy, materials, and information.
• D. A culinary program for city cafeterias.

Answer: (C)

Urban metabolism treats the city as a living system of flows. It looks at how energy, water, materials, and information move through urban networks—the inputs that enter, the processes that transform them, and the outputs like wastes and emissions. In planning, this perspective helps map where resources are used, where losses occur, and how to redesign infrastructure, building systems, transport, and land use to improve efficiency and enable circular, integrated solutions. By focusing on flows rather than just fixed assets, planners can target interventions such as district energy networks, water and waste management improvements, material recycling, and data-driven services. The other options don’t fit this city-scale systems view: budgets describe financial accounting, metabolism of individuals is a biological concept, and a culinary program isn’t related to urban infrastructure and flows.