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Supported by ������̳ and initiated by the architecture firm PCA-STREAM, the Ville Métabolisme Chair is an interdisciplinary research-action program backed by Groupama Immobilier, Artelia and PCA-STREAM. It relies on a collective dynamic to explore new questions about the city as a research subject, offer courses and invent innovative training programs.

Cities are built environments where ecological dynamics and technical activities are interwoven. Their quality of life depends on phenomena at the interface between the biological and the social. To address this complexity, the Chair proposes viewing cities as metabolisms, or as spaces where various metabolisms coexist.

The objective is to develop collective urban expertise based on a highly multidisciplinary scientific approach. This expertise aims to combine quantitative and qualitative approaches to develop integrative methodologies capable of embracing the complexity of urban phenomena. At the crossroads of ������̳'s disciplines, the Chair organizes innovative research and training initiatives. It brings students together to impart interdisciplinary skills and explore new ways of designing, building, and living.

The metabolic city: understanding how human intervention in urban areas can be harmoniously linked to ecological conditions

For living beings to survive, reproduce, develop and move, they need to exchange with their environment. To achieve this, they need metabolism: a network of biochemical interactions and reactions.

Metabolism refers to two broad categories of processes taking place on a molecular scale, to build complex molecules from simple ones ("anabolism") and to break down complex molecules into simple ones, releasing energy ("catabolism").

Metabolism is a network of biochemical interactions and reactions that enable living beings to sustain life, reproduce, develop and move, thanks to exchanges with their environment.

What about cities? How do they maintain and develop? Metabolism has been used in architecture to describe the utopian vision of megacities endowed with flexible, shifting structures, capable of expanding on a large scale in the image of an organic growth process (the Japanese "metabolist" movement of the 1960s), or in urban studies to describe the flows and exchanges of materials— energy, water, nutrients, waste— circulating in cities as they would in a body ("urban metabolism").

Alongside these analogies, the metabolic city can be defined as a space where a wide range of metabolisms coexist, at work in both human and non-human living beings (animals, plants, micro-organisms, etc.). The ways in which cities are built and inhabited are linked to the multiplicity of these organic forms. At several levels, countless metabolic activities take place in them, associated for example with nutrition, mobility, breathing and the sleep cycle.

We therefore need to understand how human interventions in urban areas can be harmonized with ecological conditions.

On a different scale, studying the metabolic city also means looking at the diversity of human practices aimed at transforming and recomposing existing elements in built environments. Repairing, reusing, repurposing, renovating, rehabilitating, reallocating, remediating, decontaminating, restoring, renaturalizing, rewilding and so on. All these activities-at the intersection of material, biological, ecological, technical and institutional dynamics— invite us to consider urban territories as evolving phenomena to be studied from a historical and prospective perspective.

• March 3-7, 2025 : PSL-Week
• May 22-23, 2025: International symposium on the notion of "metabolic city".

• September 21, 2023: Lecture "The l" by Perig Pitrou as part of the 2023 " Sustainable cities " scientific cycle (ENS - PSL) 
• October 5, 2023: Round-table discussion "Exploring the living city in an interdisciplinary framework: Crossed perspectives of professors, young PhDs graduates and students from Malaquais" (École d'architecture Paris-Malaquais)
• October 26, 2023: Workshops: the city around you, bringing together professors, researchers and students (Centre Mazet de la Vie étudiante PSL)
• November 28, 2023: Round-table discussion "Engineers and the city. Towards an ecologization of science" (Mines Paris - PSL)
• December 18, 2023: Round-table discussion "Urban archaeology and history: the creative evolution of the city of tomorrow" (EPHE - PSL)
• February 5, 2024: Inauguration of the Ville Métabolisme Chair 
• March 4-8, 2024: PSL-week "Metabolic city: observing and analyzing living indicators”
• May 6, 2024: Seminar "Urban metabolism: a critical bio-inspiration" with Christophe Goupil
• June 3, 2024: Seminar "Towards a science of cities" with Marc Barthelemy
• June 24, 2024: Workshop at Artelia
• August 28-31, 2024: Seminar in Saint-Dizier
• October 04, 2024: Workshop at PCA

Natural sciences now provide a wealth of measurement tools and models with which to examine living systems. Through the transferring of knowledge, but also through constructive dialogue with the social sciences, architecture and urban planning, natural sciences researchers propose to assess the relevance of these measurement tools and models for questioning cities and their relationships with the territories that surround them. In particular, the aim is to identify parameters that describe the physiological state of a city in the same way as we might describe the physiological state of a living organism, and, when appropriate, to identify actions that can restore the city to an optimal condition.

Urban territories and ecological ecosystems are systems in constant evolution. This evolution is evident in population changes, variations in biodiversity, and transformations in form and function in both natural and built environments. From the most visible architectural heritage to the most far-reaching urban planning decisions (infrastructures, traffic routes, interchange zones), cities are made up of strata where various spatialities and temporalities intermingle and connect. By adopting an archaeological, historical and geographical perspective at these phenomena, we can decipher how past events and practices shape current ways of living and navigating in contemporary cities.

To keep themselves alive, living beings must actively find energy by feeding and breathing, and to establish interactions with their environment. These phenomena are also inseparable from the way we design cities and build spaces in which to support the well-being of living beings, both human and non-human, to feed, care for, protect and cultivate them. Furthermore, cities, like all technical systems, are maintained in good working order by a wide variety of technical activities. Cleaning, repairing, replacing, recycling, renovating— the list of essential technical actions is extensive and constantly evolving.In a dialogue with the natural and engineering sciences, fieldwork in sociology and anthropology questions these maintenance activities, involving living beings and technical objects, and invites us to study the multiplicity of materializations (extension, replacement, destruction, etc.) that occur in cities.

Depending on the city or district, living conditions vary, and can improve or deteriorate. These differences can be objectively assessed by analyzing data (demographic, economic, sociological, epidemiological, toxicological, etc.). To fully assess quality of life, the subjective experiences of residents are also of interest, as it can vary according to age, gender, social category or origin. These integrative approaches are also enriched by considering data relating to the urban environment (e.g. soil, air, and water pollution), and the presence of living non-humans (animals, plants, micro-organisms, viruses) can have positive or negative effects on living conditions. This multi-faceted approach explores the possibility of assessing a city's "good health" to intervene and deal with dysfunctional situations.

Architectural and urban planning projects are not defined solely by technical possibilities. They are conceived and carried out with consideration for a diverse range of norms and values: legal, economic, aesthetic, religious factors. Highlighting the institutional logics that frame and guide interventions in urban territories is a major challenge in identifying the constraints and opportunities with which the players involved in city governance have to contend. This reflexivity on human and social determinants aims to improve the development of instruments to inform decision-making in urban planning and architecture, by more effectively integrating the results produced by scientific research.

Through their capacity for sensitive explorations of urban territories, the arts offer alternative perspectives on the city that enrich scientific investigations, by establishing a critical distance if necessary. Research-creation projects shed new light on the city, by revealing the dimension of relationships between people and inventing possible worlds, each with its own logic and meaning. By drawing on the resources of art, reflection on the metabolic city can be applied in projects involving the creation of images and imaginary worlds, design experimentation and performances, all seen as ways of re-inhabiting urban territories.