The Weight of Cities

This text is an elaborated version of the editorial by Carlo Ratti¹ and Mette Ramsgaard Thomsen² published in the proceedings of the UIA World Congress of Architects 2023 Copenhagen (Springer)

¹ Professor and Director of the Senseable Lab, MIT (US),Founding Partner of Carlo Ratti Associati (IT)

² Professor and Founder of the Centre for IT and Architecture research group (CITA) at the Royal Danish Academy of Fine Arts,School of Architecture, Design and Conservation (DK)

INTRODUCTION

“How much does your house weigh?” Buckminster Fuller famously asked this question in the 1920s, while promoting his lightweight, mass-produced Dymaxion house that he hoped would democratise homeownership in the same way that the Model T had done for cars. The 1929 version provided an incredible ratio of living space to mass: 150 square metres for only 2700 kilos (Reed 2002).
The question of weight was effective because it focused people’s attention to a concept that most people never considered – we think of buildings as static elements of the built environment, not objects that weigh down upon it. But as the climate crisis threatens cities everywhere, Fuller’s question is becoming a heavier one. Much of a building’s weight does not press into the ground, but instead floats in the atmosphere and traps sunlight. Mass often indicates embodied energy and CO2 2 emissions. In other words, we may not feel the weight of the built environment, but the planet does. We need to lighten the load.

1:Towards a metabolistic architecture

Conceptualising the weight of cities is at the heart of the field of industrial urbanism and the subject of the UN Resource Panel’s reports (IRP 2018). Here, “weight” stands for all of a project’s environmental impacts across its life cycle. By asking us to consider cities as a circular metabolism through which resources flow, challenging 20th century perceptions of resources as fundamentally neutral, apolitical, and endlessly available at market cost. This aligns with the work of researchers such as Mark Swilling and Marina Fischer-Kowalski, who warn us of the hidden costs of resource ignorance.
But how do we measure the weight of the city? As designers we can consider how every pound of material we employ falls differently on the scales of sustainability. We could even say that there are forms of “positive weight” and “negative weight.” Producing a tonne of concrete generates around 600 kilos ofCO2 (Nature 2021), but producing one tonne of dry timber actually removes 1.8tonnes of Co2 from the atmosphere (Cambridge 2019).
To rebalance the scales of urban life, we first need to get better at measuring them. It may seem daunting to account for carbon, land, energy, water, raw materials, and cost, but digital technologies are giving us a 21st-centurytoolkit that is up to the task. As we craft the buildings of the future, “digital twins” and Life-cycle Assessment (LCA) allow us to track the emissions implications of every design choice. Advanced sensing technology and artificial intelligence analysis allow us to track – precisely and in real-time – how our models hold up in the real world. These sophisticated simulations and their real-life counterparts in sensor data enable critical assessments of design in context of how resources are deployed, their intensity, and their performance.
Further expansions of these methods push us to integrate end-of-life scenarios into early-stage design. Now we can conceptualise not only the construction and lifecycle of a building, but also how its raw materials can be reused long after a given project is no more. Designing for adaptation, for disassembly, and re-materialisation challenges the conceptualisation that design is an end-point, instead positioning it as an intermediate along the cascading flow of materials where resources are not only extracted, transported, used and disposed, but also filtered for multiple reuses.  
Could weight become a means of accounting for resource flow through our larger built environment? If lightness directed the postmodern movement through high-tech visions and profit-driven axioms of resource optimisation, weight here implies both conceptual and direct ways of broadening designers’ visions to consider the impact they make on the wider world.

2:Consequences of weight

But what is weight in context? The core message of our report is that a city’s well-being, its sustainability, and its ability to design and manage its material flow are closely tied with its ability to produce social equity(ibid). Resources are inevitably deeply entangled in the socio-ecological networks of their extraction and deployment.
Resource deployment and design have deep impacts on surrounding communities and ecologies, so they are fundamentally ethical decisions. Today, we might be conscious of a particular endangered species or build awareness of specific unethical fabrication processes, but we lack consolidated models to steer the impact of design decisions on their socio-ecological contexts.
These models can be high and low-tech. On the one hand, systems design and resilience modelling enable the analysis of socio-ecological systems and the way extraction impacts on their embedded balances (Tamberg 2020). On the other, newmodels of grassroots-driven, participatory, and community-focused resource thinking challenge globalized industrial building practice, instead insisting on the localisation of resource and building technology. Local crafts, traditional knowledge, and a return to grown resources allow alternative ways of accounting for and sustainably ensuring resource longevity.
What results is a challenge to the embedded universality of the concept of weight. As if we were standing on different planets with different gravities, weight is not the same from place to place. While this insistence on context and place supports the rupture with resources as neutral and apolitical, it complicates the transferability and value of its results.

3:Building vision on a global research stage

It is through this complexity we enter the conceptualisation of the UIA2023CPH panel Design for Rethinking Resources. It draws upon the UN Sustainable Development Goals (SDGs) and 2030 Agenda, whose central, transformative process is ‘leave no one behind’. In adopting and situating this agenda for architecture, this promise is a guide for the UIA2023CPH World Congress. Together, our global collegiate of designers, researchers, and educators report on a wide array of projects that challenge, rethink and propose new ways for architecture to understand its material practices.  
In this new paradigm architecture and design expand are ethical practice, concerned with how the flow of materials impacts environments and people. The SDGs ask us to consider our material footprints. For example, indicator 8.4.1(UN2022) asks us to measure the attribution of global material extraction per capita and per GDP to be able to understand the impact and equity of consumption. In one of our pre-events leading up to the congress, resource management theorist Helmut Rechberger asked us to address not just resource scarcity, but also the impact that business-as-usual models have on our landfills. Challenging us to imagine the projected weight of the city of Vienna and the fact that it will double by 2050, Rechberger reminds us that cities act as unwanted end-points for resources at the end of their lives.
Design for Rethinking Resources journeys through these questions. Through the six chapters collecting 46 papers, authors present novel scientific research questioning what resource streams, practices and associated technologies can amount to a sustainable architecture. They argue for the (re)introduction of new and old crafts, conceptualise the city as a resource bank, sketch new computational practices, ideate bio-based renewables, and imagine the post-extractive practices of tomorrow.
Our effort started by reading through the SDGs and finding that resources are a cornerstone of all 17 goals. The SDGs ask: Who has the right to resources? Who extracts? What pollutes? What ecosystems are implicated in extraction? Who has access and at what cost? What are our relative material footprints, from country to country and from Global South to Global North? How can technology ensure resource efficiency? How can we balance social and environmental needs?
In response, we have defined Design for Rethinking Resources across six questions defining six sub-panels together challenging the way resources are thought across architecture. Each question has attracted papers from a global community across disparate sub-fields creating new interfaces between knowledge fields. In line with the wider UIA2023CPH Scientific Committee focus on fostering broad inter-cultural exchanges, our aim is to create an interdisciplinary global conversation.

4:Six questions for Design for Rethinking Resources

Chapter1: Post-Extractive Visions 

The proceedings start with a series of provocations. Arriving from different corners of the field, the papers imagine architecture beyond extraction. They offer a broad critical assessment of past and present extractive practices and their impact on various ecologies. They ask us to question what post-extractive technologies might be and how biological technologies that employ living organisms for material production can present new horizons for the way we understand the built environment.

Chapter2: Localising Resources

Resource management challenges the way we understand equality. The second chapter prompts us to rethink the globalisation of resource deployment. “Localising Resources” asks how participatory and community-focused local resource thinking can challenge the way we work with materials. From eggshells to recycled timber, from earthen bricks to coconut fibres, the chapter presents a series of cases demonstrating how “thinking local” can foster socio-ecological networks that facilitate meaningful and contextualised resource cascading.

Chapter3: Heritage to High-tech

Local resources entail local craft. “Heritage to High-tech” positions craftsmanship in the context of resources. It reminds us how local traditions and vernaculars are situated in sensitively balanced socio-ecological networks that already incorporate circular principles. In developing this position for a sustainable future, it asks both to carefully examine what these practices entail and what their interfacing with transposed building knowledge and new technologies canbe.

Chapter4: Fabrication Futures

Digital modelling, analysis, and fabrication allow us to innovate design practice. Advanced modelling for material optimisation, cyber-physical augmentation along with LCA, digital twins, material passports, and data basing for resource stock suggest new territories for data-driven material management. “Fabrication Futures” asks us to rethink how materials are deployed. Designing fordis assembly can help us to imagine a more flexible and reconfigurable building stock.

Chapter5: Restarting from Renewables

“Restarting from Renewables” asks us to imagine our material world as one we are co-producing with nature, transforming the perception of our surroundings from something inert to something alive. They also implore us to embrace biomaterials. By spanning different technological perspectives, from the traditions of bamboo construction to the fermentation of mycelium-reinforced weaves to the implementation of biochar cementitious composites, the papers present a series of cutting-edge case studies.

Chapter6: The Value of Wast

Circular principles ask us to reconsider the waste streams of production. How can models of cascade thinking and recycling reallocate resources? What models of circularity can transform production and mitigate waste streams? The Value of Waste asks what are the necessary infrastructures for cascading and how can buildings, cities and the wider built environment be understood not only as shelters for the present, but as resources for the future.

Conclusions

With our new research, we could finally address problems around cities and sustainability that have bedeviled us for decades. In 1995, Richard Rogers called for architects to “define an ethical stance,” and create sustainable buildings that “work into the cycle of nature.” He noted that “cities are consuming three-quarters of the world’s energy and causing three-quarters of the world’s pollution,” and warned that these environmental consequences would only worsen because “over the next thirty years, a further 2 billion people are expected to be added to the cities of the developing world.” (Rogers 1998)
Those decades have gone by, but the condition Rogers described has only grown more urgent. Today the effects of climate change are here, and thirty years from now the urban population is projected to double again.
Now, finally, a new shared research foundation in our field has a chance to truly change our trajectory. The linear economy has condemned our resources and planet to the same one-way path from extraction to waste. Embracing a fundamental change in mindset about the costs our built environment incurs can take us to new tracks. We must develop the consciousness – of cities, of the environment, and of ourselves – which Buckminster Fuller exhorted us to acquire when he first asked what a building weighs. Instead of weighing us down, our buildings and our cities can lift us up.

References

IRP(2018). The Weight of Cities: Resource Requirements of Future Urbanization.Swilling, M., Hajer, M., Baynes, T., Bergesen, J., Labbé, F., Musango, J.K.,Ramaswami, A., Robinson, B., Salat, S., Suh, S., Currie, P., Fang, A., Hanson,A. Kruit, K., Reiner, M., Smit, S., Tabory, S. A Report by the International Resource Panel. United Nations Environment Programme, Nairobi, Kenya.

Tamberg, Lea & Heitzig, Jobst & Donges, Jonathan. (2020). A guideline to modelling resilience of complex systems.

SDG indicator metadata (2022)https://unstats.un.org/sdgs/metadata/files/Metadata-08-04-01.pdf

Rogers, Richard. Cities for a small planet. Westview Press, Boulder Colorado (1998). pp27.

Reed, Peter in Matilda McQuaid, ed., Envisioning Architecture: Drawings from The Museum of Modern Art, New York: The Museum of Modern Art, 2002, pp. 64-65.

“Concrete needs to lose its colossal carbon footprint.” Nature 597, (2021). pp 594 - 597.https://www.nature.com/articles/d41586-021-02612-5

“Sowing seeds for timber skyscrapers can rewind the carbon footprint of the concrete industry.” University of Cambridge (2019).https://www.cam.ac.uk/research/news/sowing-seeds-for-timber-skyscrapers-can-rewind-the-carbon-footprint-of-the-concrete-industry