Circular Metabolism


From Concept To Tangible Practice

More Than Just A Flows Audit 

Cities and regions can't function without constant flows of materials, water, sediment, energy, food, air, biomass, data, and so on. Metabolic studies research these flows and map them, which is how heat maps, potential maps, flow charts, etc. are created. In the past, these studies were often limited to a kind of audit exercise with input and output data of flows and stocks. Their objective was chiefly to optimise individual flows. While there’s nothing wrong with this, a city is still made up of more than the sum of its individual flows. Models, analyses and indicators are needed and can raise awareness; however, they rarely generate insights into the 'spatial planning footprint' of flows, daily dynamics and management, accessibility of flows, and how governments and other players can take action on this front.

Taking The Context Into Account

It’s for that reason that circular metabolism studies should explore the context of specific areas in which those flows occur. Thanks to the link between research and design practice current studies take this into account. Different agendas (citizens, public authorities, businesses, territory, etc.) are systematically taken into account, and local knowledge and valuable initiatives are inclusively integrated (see figure). As a result, these studies are always tailored to specific places, on a community scale (place-based). In our opinion, that’s really what working with circular metabolism is all about.

Flow Chart: It's More Than Just Flows

Why Are We Doing This?

Circular metabolism is a useful metaphor for research, design and policy. Through metabolism, everyday aspects of urban life are reassessed. Where does the water running from the tap come from? What happens to my rubbish bag after I put it out on the street? The metabolism doesn’t just show how urban life works but also exposes the financial, social and environmental costs borne by the city (source: Agora). And that’s why Circular Flanders and its partners stimulate research and encourage new practices inspired by urban metabolism at various locations throughout Flanders and Brussels.


Using Flows In Design

Master Classes

We organised three master classes, 'Designing With Flows’, in the slipstream of BOZAR’s A Good City Has Industry exhibition, where the results of the Atelier Brussels at the International Architecture Biennale Rotterdam (IABR) were presented.

The master classes were a collaboration with the Flanders Environment Agency (VMM/MIRA), the Flemish Government Architectural Team, FABRICations and the non-profit organisation, Metabolism of Cities. Their primary purpose was to familiarise participants with the theory, concept and practice of ‘circular metabolism’. In this relation, we were also interested in starting and contemplating a shared agenda, while also seeking to foster a partnership made up of incredibly diverse actors.

'Serendipitous Outcomes'

The debate set in motion by the master classes resulted in some serious, rather serendipitous outcomes:

Publications and Articles

Additional Research/Academic Work

Communities and Seminars

Triggering Debate

Review the lectures, interviews or download the summary report:


Antwerp, City of Flows

‘The Metabolism of Antwerp, a City of Flows' is a research-by-design project on nine types of flows in and around Antwerp: energy, water, food, air, goods, waste, people, mobility and biomass. The project mainly focuses on the opportunities they offer to set Antwerp up for a future as a circular city

Antwerp, The Guinea Pig

The design research into the 'Metabolism of Antwerp, City of Flows' was set up in 2016 by a unique coalition of the Flemish Government Architectural Team, the Department of Environment, OVAM, the City of Antwerp and the Port of Antwerp. The project addresses the question of how goods, biomass, waste, energy, people, air and data travel in Antwerp. How do these flows affect the the quality of life? Where can the most opportunities be found? On the one hand, the project needs to feed into the update of the Antwerp Strategic Spatial Planning Structural Plan (s-RSA for short). On the other, the city can function as a test case for investigating how we can close loops on a larger scale and evolve towards sustainable, circular cities

Flows > Challenges > Solutions 

The city of Antwerp itself requested the metabolism study to improve its consideration of the many flows in and around the city. Eight key flows were addressed: energy, water, food, air, goods, materials, people and 'biota' (plant and animal life of the region). Appointments and indepth interviews with experts, internal brainstorming sessions with city services, supplemented by desk research and historical analyses all contributed to the study of these flows. For each flow, the infrastructure and its use or role was mapped. The region, city and street’s main challenges were also sketched as part of the overall picture. In this way, a transition was made from facts and analyses to challenges and promising projects.

Promising projects often respond to multiple flows simultaneously. Four crossflow themes were highlighted: heat (energy transition), air quality (healthy living), circular building materials (a circular economy) and drinking water (climate adaptation). For each theme, a project was developed in detail, including what its relevance is to Antwerp, how to implement the project and who should be involved.

The evolution towards a circular city is still at an early stage, but little by little, it’s starting to take shape. In the Inspiration Note for the new Antwerp Strategic Spatial Planning Structural Plan, for example, the 'short-distance city' has become an important principle. Circular entrepreneurship and flow management are important starting points for new policy and concrete urban projects.

City Debates

One of the research project's unique characteristics is that, in addition to the usual expert sessions, public 'city debates' were also organised to gather input. Members of advocacy groups, administrations at different levels, business managers, researchers, students, designers and interested citizens participated in these debates.

© Frederick Beyens