Accounting for urban material and energy flows

John E. Fernández, professor in the Department of Architecture and Director of MIT’s Building Technology Program, is at the forefront of urban sustainability. Urban metabolism is an emerging science that gives urban stakeholders—officials, businesses and communities—insight into the resource intensity of cities, neighborhoods, and campuses.

Physical accounting for urban economies

Urban metabolism seeks to understand the physical requirements of cities. Like the human body, cities consume and expel materials and energy. Fernández is pioneering physical accounting for the origin and flows of resources like biomass, water, fossil fuel energy, industrial minerals and materials into cities, neighborhoods and now university campuses and other organizations. The analysis is analogous to financial accounting in business. 

He conducts classical urban metabolism studies throughout the globe, quantifying a city’s resource intensity in places like New York City, Boston, Lisbon, Singapore, and cities in Peru, Chile and soon India and Africa. But his team knows that quantifying consumption rates is just the first step. Fernández, who is also co-Director of the MIT International Design Center, is spearheading other projects that include clustering 100 cities into profiles to develop a typology of urban resource consumption around the world. Once the typology is complete, researchers will be able to measure and extrapolate the resource intensity of any city based on known factors.

One goal of the work is to propel cities and municipalities to be more aware of the resources they acquire and consume. Stakeholders need to gather data and make it available to the public so that people have a more holistic understanding of what their consumption really is.


His work is also to track cities in China and South Africa as they transition from low-intensity to high-intensity and vice versa. Urban metabolism reveals the resource intensity of a city, neighborhood or campus, and helps policy makers and city officials to set pragmatic resource use, recycling, and energy reduction targets using a more scientific foundation.  It also empowers other stakeholders to prepare for targeted reductions. Through the MIT Portugal program, Fernández is leading the Urban Technology program, which will introduce advanced urban technologies into neighborhoods in Portugal to examine how resource consumption changes.

For companies like Infosys with large campuses, their operations are like those of a small city. In Bangalore, Fernández and his team are leading a project to account for the physical demands of the company’s buildings. The project demonstrates that urban metabolism can be adapted to fit organizations for site selection, supply chain planning, construction and infrastructure development. 

Urban metabolism is an extremely powerful tool to give sustainability managers another insight into the ways they use resources and helps prioritize their efforts.

One example is the work Fernández has done with the Office of Sustainability on the MIT campus. After conducting a study of the campus’ urban metabolism, the team can analyze procurement to understand the volume and rhythm of purchasing at MIT and identify potential efficiencies. Other campuses and institutions are unique in the control they have over procurement policies and have already expressed their interest in urban metabolism. With an understanding of resource flows, managers can set a metric called material intensity per unit of service (MIPS). It is one way to link services with the material resource required to deliver that service. The fuel needed to drive one mile, or the amount of food needed to feed a person are just two examples.

Urban metabolism is just one of several different fields trying to get people to think about production and consumption differently. Fernández believes it’s important for sustainability leaders to understand urban metabolism can be applied at the operational level to tackle the low-hanging fruit. While some companies already have very sophisticated lifecycle inventories, it is rare to see material flow analysis that identifies the places where resource-use is most intensive. Although this is but one among several tools for managers, urban metabolism accounts for the impact of those flows on communities where their operations are located. He strongly believes in reexamining consumption and considering efficiency first before investing in sexy high tech solutions. “The smartest dollar is spent in reducing consumption before investing in alternative energy. Of course, eventually both should happen.” He hopes the field of urban metabolism will help to facilitate this transition to a new resource efficient economy.