Biomaterials in regard to architecture, design, and construction are materials derived from living organisms or nature. These often have lower embodied carbon. These materials are also known to sequester carbon and lock it in for the lifespan of the materials’ use. Biomaterials have been predominantly used for medical applications due to their non-toxic nature, but now find new ways of occupying built spaces.
Opportunities and Challenges
Bio-materials are benign materials that show promising structural capacities and potential to replace traditional construction materials. Some bio-materials like wood and hemp can be used in their raw state, while others, such as algae and food waste, are combined with other materials to create composites. Biomaterials have also shown promise in pushing material innovation by addressing issues like self-healing and also challenging the aesthetic appeal of buildings that society has come to expect. In some cases, bio-materials have managed to bridge the gap between human habitats and proximity to nature. However, these materials also bring with them some challenges.
The existing building construction industry often does not have the infrastructure to produce and scale the production of bio-materials. The existing building codes don’t have the flexibility to experiment with the application of such materials. The process of getting a novel biomaterial certified to industry standards is extremely difficult and expensive as the testing standards are based of traditional construction materials that function very differently from that of bio-materials. It is also to be noted that most of the applications for a material are in tandem with the design considerations and structural geometry, something that material testing does not account for. In this article, we will look at a few innovative biomaterials and their applications in the building construction industry.
Mycelium
Hy-Fi, designed by David Benjamin of New York architects ‘The Living’. The tower was designed as part of MoMA’s Young Architects Program. It was the first large structure to use mushroom brick technology, a technique developed by Ecovative in 2007. The bricks were grown in 5 days and stacked to create. Structure of three colliding cylinders. At the end of the exhibition, the mushrooms were composted and returned to the carbon cycle.
Mycelium is a unique material that cultivates certain species of fungi in substrates that act as nutrients to the species. Some of the substrates commonly used include straw, sawdust, grains, and coffee. This process begins by inoculation using a mushroom spawn, which then forms a fungal network of interconnected mycelium that eventually forms a self-supporting composite. During this process, it is important to monitor the temperature, humidity, access to oxygen and light.
This process is usually undertaken within the confines of a mould to ensure that the mycelium reaches a desired shape that is in tandem with the intended design. Once the mycelium has fully occupied the mold, it is either fully dried by firing, preventing any further growth, or is partially dried so it can be rehydrated to achieve a fully homogenous form that is built by parts
Some of the fascinating properties of Mycelium, that make it a promising material for the future, are as follows. Mycelium is fire resistant, has excellent acoustic properties, is extremely lightweight, and has the ability to grow into any mold. Which is why it is being considered as a material that can help build Mars habitats.
Algae
Algae, by definition, are a group of predominantly aquatic, photosynthetic and nucleus-bearing organisms that lack true roots, stems, leaves, and specialised multicellular structures of plants. Algae are known for purifying the air; they filter carbon dioxide and pollutants in the air and convert them to biomass and oxygen through photosynthesis. The biomass generated is further processed to form biopolymers or to generate energy.
A scaled architectural application of this living creature as a building material can be observed at the Solar Laef project by Arup. The Solar leaf project is the world’s first facade system to cultivate microalgae to generate heat and biomass as renewable energy
Situated in Hamburg, Germany, 1292.5 x 0.7m bio-reactors were installed on the southwest and southeast facades of a four-storey residential building, working as a secondary facade. Solar Leaf reportedly produces one-third of the total thermal demand of 15 residential units. Made of four layers of glass, the two inner panes form a 24-litre cavity, where the growing medium circulates. Argon-filled cavities between the panels help minimize heat loss. Compressed air is introduced at the bottom of the biobioreactors at regular intervals to simulate the algae absorbing CO2 and light.
The heat harvested by the facade is transported by a closed-loop system to the building’s energy management centre where the biomass is harvested. This project shows the ability of bio-materials to be applied to scale successfully with tangible performance metrics and also challenges the notion of traditional green facades.
Silkworms
This material has been available to mankind for a long time; it even warranted large trade routes to exchange this valuable material. With robust fibres and a beautiful sheen, silk has been a fascinating material. However, traditionally, it is harvested by killing the worms that spin silk. Oxman Lab, headed by Neri Oxman, asked a different question. How can we extract silk without boiling cocoons? Can silkworms be treated as design agents and partners?
This led to the development of the silk pavilion. 17532 silk worms were placed on a kinetic jig that constantly rotated clockwise, facilitating the silkworms’ upward spinning motion, after 15000 jig rotations and accounting for all the environmental variables that affects the abilities of the silk worm, the pavilion.
The pavilion is made of three interrelated layers, the innermost layer is the primary structure, consisting of one-dimensional braided steel wire ropes. The secondary structure is a two-dimensional fabric on which silkworms are positioned. The tertiary – three-dimensional structure is biologically spun 7240 miles of silk thread. The project was able to showcase that silk could be extracted without boiling the cocoons and resulted in architecture-scale structures where non-human entities co-fabricate.
Biomaterials have a myriad of applications and have great potential to scale and replace architectural materials as we know them. There are more examples of biomaterials in the construction industry, like programming calcium-producing bacteria to help heal materials and valorize waste to create new industrial-grade materials. Biomaterials are not only benign to the environment but also advocate for a more inclusive practice of architecture and construction that involves non-human entities and benefits all the stakeholders of a project. It truly embodies the philosophy of humans and nature sharing a symbiotic and harmonious relationship.
Refrences:
Karro, S. and Leet, K. (2022) ‘Mycelium Materials: The Future of Growing our Homes’, ArchDaily, 20 July. Available at: https://www.archdaily.com/985570/mycelium-materials-the-future-of-growing-our-homes (Accessed: 7 April 2025).
Stott, R. (2014) ‘Hy-Fi, The Organic Mushroom-Brick Tower Opens At MoMA’s PS1 Courtyard’, ArchDaily, 27 June. Available at: https://www.archdaily.com/521266/hy-fi-the-organic-mushroom-brick-tower-opens-at-moma-s-ps1-courtyard (Accessed: 7 April 2025).
Oxman, N. (2020) ‘Silk Pavilion II’, Oxman. Available at: https://oxman.com/projects/silk-pavilion-ii (Accessed: 7 April 2025).
Hanafi, W.H.H. (2021) ‘Bio-algae: a study of an interactive facade for commercial buildings in populated cities’, Journal of Engineering and Applied Science, 68(1), Article 37. Available at: https://jeas.springeropen.com/articles/10.1186/s44147-021-00037-5 (Accessed: 7 April 2025).
Arup (n.d.) ‘SolarLeaf, the world´s first bio-reactive façade’, Arup. Available at: https://www.arup.com/projects/solarleaf/ (Accessed: 7 April 2025).
Ghisleni, C. (2022) ‘What Are Biomaterials in Architecture?’, ArchDaily, 24 August. Available at: https://www.archdaily.com/987658/what-are-biomaterials-in-architecture (Accessed: 7 April 2025).
