Karlsruhe Institute of Technology, Faculty of Architecture
Prof. Dr. Dirk Hebel
MycoTree, 2017
Mycelium and bamboo
100 x 100 x 150 cm
Courtesy Karlsruhe Institute of Technology, Faculty of Architecture
The MycoTree is the result of a collaboration between the Chair of Sustainable Construction at the Karlsruhe Institute of Technology (KIT), the Block Research Group at the Swiss Federal Institute of Technology (ETH) Zurich, and the Department of Alternative Construction Materials at the Future Cities Laboratory in Singapore.
The Frankfurter Kunstverein is showcasing one of the prototypes of the exhibit, which was presented as a central work at the 2017 Seoul Biennale for Architecture and Urbanism. MycoTree illustrates how regenerative resources, combined with architectural planning, have the potential to create alternatives to established methods, and building materials for a more sustainable, bio-based construction industry. To achieve the requisite stability in construction, such sturdy traditional materials as metal and concrete are no longer relied upon, given their heavy ecological footprint and depletion of planetary resources. Instead, KIT focuses on stability through modified geometric design in the planning process. Led by Prof. Dipl. Arch. Dirk E. Hebel, a professor in the Department of Design and Sustainable Construction at the Faculty of Architecture at KIT, intensive research is being conducted on sustainable processes and materials for the construction industry.
The MycoTree is a model-like, spatial branching structure that was constructed from various mycelium and bamboo components. The name MycoTree refers to its tree-like structure. The form serves as a model of natural geometry, which is then further developed and calculated by architects and with the 3D-Graphic-Statics program. Within the MycoTree structure, modular components were attached using connectors made from bamboo, likewise a renewable resource.
The MycoTree is composed of organic materials. The white construction modules are made from residues of agricultural, forestry, or textile industries, held together by mycelium. The main production steps envisage particularly controlled conditions so that the living fungus finds optimal growth conditions. The organic residues are sterilized, fungal spores are added to them, and the mass is left to grow at 30 degrees Celsius for several weeks. If activation of the fungus is successful, it can grow at a rate of one to five centimeters per day and colonize the substrate. Once the mycelium has fully penetrated the substrate, growth is halted through drying and subsequent compression. The root filaments of the fungus compact the originally loose substrate into a solid form, replacing thereby the need for toxic adhesives. This also makes the material completely biodegradable. The shape of the containers in which the fungus grows determines the final shape of the module, as well as the success of the living fungus growth process.
These mycelium modules are connected to bamboo parts using connectors to increase the stability of the object. Bamboo is also a rapidly growing plant that can grow up to one meter in height per day. It is flexible and robust, and has played a central role in Asian construction for centuries, including in modern high-rise construction. Unlike trees, bamboo requires less water, no fertilizers, and grows much faster.
However, mycelium material is neither particularly flexible nor tensile. For this reason, a form of innovative architectural and structural planning needs to be developed with the characteristics of organic materials. The MycoTree was created as a prototype and module at KIT Karlsruhe to test its load-bearing capacity.
International research has been conducted on the method of mycelium preparation from organic waste for years, and patents filed. Today, numerous methods and suppliers of different materials exist, whose texture range from light but crumbly to hard and compact. These meet various construction project and interior design needs, such as sound absorption, low flammability, sealing properties, or the ability to be pigmented. In biochemical terms, during their growth both the fungus and the bamboo plant bind nitrogen and carbon, which are stored in cellulose.
The 21st century is on the brink of a radical paradigm shift in how we produce materials for building our living spaces. The linear concept of “produce, use, and dispose” has proven unsustainable for living on the planet in future, given the scarcity of resources and exponential growth of urban populations. To achieve a circular cycle of production, entailing use and reuse, alternative materials and construction methods must be explored and then implemented.
A shift in mindset has occurred in the international architecture context, as shown by the 2023 Venice Biennale for Architecture. However, neither construction practices and the supply industry, nor regulatory and political frameworks reflect the transition to a new way of building. Rapid urbanization, global resource consumption, and the associated ecosystem destruction remain some of the greatest challenges of the 21st century.
Prof. Dipl. Arch. Dirk E. Hebel founded the research institute he leads in the belief that a paradigm shift must urgently make headway in the construction sector. Since 1990 alone, estimated greenhouse gas emissions from the cement industry worldwide have tripled. The global construction industry requires exponentially increasing amounts of wood, water, soil resources and energy. This makes it a major contributor to deforestation, land consumption, water pollution, and non-recyclable construction waste. The extraction of sand that is used in concrete production depletes ecosystems. Sand is taken from rivers, coastlines, and sea beds, leading to habitat destruction for humans, animals and plants.
With a growing population and rising demands, the need for materials and resources to satisfy them is also increasing. While in the past, this demand on resources was met locally and regionally, it is now becoming increasingly global and far-reaching. This phenomenon has led to the emergence of material flows of transcontinental and planetary significance. These have profound implications for the sustainability, functioning, ownership and identity of future cities. The global concentration of the construction industry on a few select materials is putting significant pressure on our natural resources, however. In any discussion of cities of the future, it becomes that clear that they cannot be constructed with the same resources as those employed in existing cities.
Like many other participants in Bending the Curve, Dirk Hebel is an active advocate for circular economic models. This approach views materials as precious, finite resources and actively promotes their reuse and conservation. Efficiently using resources, minimizing waste, extending the lifecycle of products, and promoting material recycling: these are all possible strategies. The time for linear models, where products are discarded after use, must be left behind. A circular economy, a culture based on repair, or at the very least recycling, would have to be promoted politically to ensure that our planet remains inhabitable into the future.
