Construction contributes significantly to global emissions while it requires a large share of already diminishing resources like metals and fossil fuels. In search of more sustainable building models, ERC grantee Mette Ramsgaard Thomsen is exploring innovative ways to integrate renewable and carbon-neutral materials in architecture. The idea is to make bio-materials more adapted to tomorrow’s world.
ECO METABOLISTIC ARC is a response to the large carbon footprint of the global construction sector in an era of climate change, rapid population growth and increasing urbanisation. How can architecture adapt by using sustainable materials from renewable sources such as plants, fungi and bacteria, and how should architectural modelling evolve to be able to understand the properties of these bio-based materials and make the best use of them?
“Bio-based materials have different properties than finite materials, such as metals and fossil fuels”, Mette Ramsgaard Thomsen explains. “The latter are recognized as permanent and stable in time while bio-based materials are usually heterogeneous, have a changing behaviour and a shorter lifespan. These properties can be a challenge for architecture.”
Mette Ramsgaard Thomsen and her team are looking at the full spectrum of biogenic materials to build a holistic “eco-metabolistic” framework for sustainable architecture - from timber and bio-plastics such as polylactic acid, which is typically made using corn starch or sugar cane, to living materials such as bacteria as a potential source of light.
Using trees efficiently
“When a tree grows out in the forest, it is impacted by its environment, for instance by the soil, the fungi, the orientation of the wind, the steepness of the hill”, says Ramsgaard Thomsen. “All these elements form the tree, and determine its density and its branching. Trees are therefore different from each other and have unique properties. Conversely, the wood industry classifies the wood it cuts for building into homogenous categories.”
Furthermore, timber production generates a lot of waste and carbon because the whole tree will not be used, or it will be down-graded to wood pulp for paper production. Trees absorb CO2 from the atmosphere and convert it into oxygen through photosynthesis. When wood from these trees is used in timber products, its sequestered carbon continues to be stored for as long the products remain in use. The lifespan of timber is significantly longer than paper, for example. That is why it is essential to use all parts of trees efficiently.”
Through advanced computational modelling, Ramsgaard Thomsen and her team integrate heterogeneity in the design process. 3D scans are used to evaluate the volume of a tree and big data models allow for the analysis of all the volumetric data to be able to understand how each piece of timber can be used the best way possible. A next step is to simulate finite material performances to help architects have a better understanding of each material’s properties.
Understanding life cycles
Apart from heterogeneity, Ramsgaard Thomsen and her team are researching both dynamic behaviour and the environmental responsiveness of materials. “In mainstream architecture, buildings are seen as permanent”, she explains. Time is not considered.” Bio-based materials have shorter loops than materials made from fossil fuels. Their lifecycle varies and their behaviour is perhaps more erratic. A question that Ramsgaard Thomsen seeks to answer in her research is how to predict and model bio-based material behaviours in order to understand how they are going to alter in time.
“Timber has been used for centuries and is known to have a rather long lifespan”, she says. “Bio-plastics, on the other hand, have only recently been used in construction and have a shorter lifespan. We are trying to understand what bioplastic can mean for architecture, and how we can work with it in a sustainable and effective manner.”
The team is also experimenting with bioluminescent bacteria, which are light producing bacteria that are predominantly present in seawater, marine sediments and in the gut of marine animals. The bacteria that could be a potential source of light are being grown in a medium that was produced via 3D-printing. “For now, this is still an abstract idea because this type of bacteria produce only little light”, Ramsgaard Thomsen says “Nevertheless, it is an intuitive way of thinking about how do the bacteria evolve while studying their lifespan, colony size, available nutrition and oxidation impact. It is part of a process of designing living architecture.”
With her research, Ramsgaard Thomsen offers a new perspective on architectural design. “The industrialisation of construction and modernism brought the idea that architecture was somehow permanent”, she says. “However, we are already living in buildings that have to be maintained. Bio-based materials open up to a more participatory way of looking at buildings. As living materials, they require continuous care. In the same way as people water their plants, inhabitants of buildings with bio-based materials will nurture their house, and therewith fully participate in its life. So it changes the ideas about ownership and participation. Those are fundamental changes.”
With this, Ramsgaard Thomsen’s project resonates with the New European Bauhaus initiative, which calls on all of us to imagine and build together a sustainable and inclusive future that is beautiful for our eyes, minds, and souls. “It is an extremely interesting idea in the way that we can prototype ideas very fast and see if we can get them harvested into industry. Not only for architecture, but also for product design and conception. We need a steep change in the way we are thinking about innovation. It is important to find new ways of innovating in order to be able to reach the 17 Sustainable Development Goals by 2030 to transform our world.”
Mette Ramsgaard Thomsen is professor and head of the Center for IT and Architecture (CITA) of the Royal Danish Academy. During the last 15 years, she focused on the profound changes that digital technologies instigate in the way architecture is designed and built. In 2005, she founded the CITA research group where she has piloted a special research focus on the new digital-material relations that digital technologies bring forth. She is currently General Reporter and Head of Science Track for the UIA2023CPH world congress “Sustainable Futures – Leave no one behind” asking how architecture can contribute to the UN SDGs.