How mushrooms could shape urban landscapes
How mushrooms could shape urban landscapes
Mycelium in construction as the future of sustainable cities?
The construction industry is under increasing pressure to rethink its approach as traditional materials such as wood, concrete and steel cannot keep up with global demand. Not only are these resources running out fast, but their environmental impact is increasingly scrutinized. The search for alternatives has led to an unexpected breakthrough: mycelium, the root-like structure of fungi, is emerging as a material for green building.
Mycelium-based composites, formed when living fungi grow on organic substrates, are seen to offer potential as construction materials. Composed of a network of fungal hyphae - fine fibers measuring 1 to 30 μm in diameter - these composites leverage chitin, glucans, and proteins in their structure, giving them strength and durability. The fungi break down complex biological polymers through enzyme release, absorbing simpler molecules for nutrition and, in turn, producing a lightweight, foam-like substance.1 This low-energy, waste-reducing process transforms agricultural byproducts into valuable building materials that are both biodegradable and highly insulating. By efficiently integrating organic waste into the material, mycelium composites offer a truly sustainable solution that could reshape the future of construction.
Fig 1. Schematic illustration of mycelium at different scales.
The science of growing bricks with mycelium
Creating mycelium-based construction materials involves several scientific steps. The process starts with inoculating a growth substrate - commonly agricultural byproducts such as sawdust or straw - with fungal spores. This mixture is placed into molds to form the desired shapes. Over time, under controlled conditions of temperature, humidity, and carbon dioxide, the mycelium consumes and binds the substrate. Once the fungal mat reaches the required density and strength, it is stabilized by heat treatment, halting further growth. The final product is then dried and finished for use in various applications.2 This method transforms waste into versatile materials, such as insulating panels and building blocks, highlighting mycelium’s adaptability and potential.
Fig 2. Circularity and workflow of current manufacturing processes applied to mycelium-based materials (Bitting, S.).
Foam, flex, and function
Mycelium’s effectiveness as a construction material depends on factors like the fungal species used, the substrate’s composition, and growth conditions such as CO2 levels, temperature, and humidity. These variables allow mycelium to produce materials with diverse properties, ranging from stiff and dense to foamy and flexible. Fungi’s ability to break down cellulose, lignin, or hemicellulose further shapes the resulting material.
Production methods involve shaping the substrate during or after growth, followed by pressing and drying. Mycelium-based composites are typically categorized into foams and sandwich composites. Mycelium-Based Foams (MBFs) are low-density, porous materials with a fibrous structure, while sandwich composites feature a mycelium core bonded between two lignocellulosic layers, providing natural insulation and moisture resistance.3
These materials are increasingly used in construction for applications like building envelopes, structural components, and thermal or acoustic panels, thanks to their lightweight yet robust nature and customizable properties.
Mycelium market on the rise?
The market for mycelium-based materials is projected to exceed USD 5.18 billion by 2032.4 Several companies are at the forefront of this movement. RongoDesign utilizes mycelium and agro-industrial residues to create construction materials and design pieces, while Ecovative Design pioneers mycelium-based packaging and construction materials, focusing on sustainable alternatives to traditional plastics and building products. Mykor is developing and scaling the next generation of building insulation. MOGU develops mycelium-based interior design products, such as acoustic panels and furniture, emphasizing both aesthetics and functionality.
The implementation of mycelium as a building material is not only a technical challenge, but also a legal one. Most building codes and standards do not specifically address mycelium-based materials, requiring a case-by-case approval process, which can hinder development and enforcement. Collaboration between industry stakeholders, researchers and regulators is now underway to establish standards for mycelium-based building materials that focus on safety, performance and environmental impact.
Roadblocks and the path to widespread use
Despite its promise, mycelium faces challenges in durability, especially in wet conditions or extreme climates. Research is ongoing to enhance its resistance without compromising biodegradability.5 Water absorption is a critical factor for indoor use, particularly in humid climates. Some experts have compared mycelium to a sponge, suggesting it should be sealed with water repellent, which could potentially compromise its sustainability credentials.6 However, other studies indicate that mycelium composites, when densely grown on the right substrate, can exhibit water absorption properties comparable to or better than traditional materials like clay bricks and mortar.7
Cost remains an obstacle, with many mycelium products currently considered high-end and niche. As production scales up and becomes more efficient, prices are expected to decrease, making mycelium-based materials more competitive in the construction market.
Innovations in genetic engineering and material science hold the potential to significantly enhance the strength, durability, and growth speed of mycelium-based materials. As awareness of mycelium's benefits grows and production becomes more cost-effective, its adoption is expected to rise, potentially establishing it as a mainstream construction material.
Ongoing large-scale trials and pilot projects using mycelium in various construction applications will be crucial in demonstrating its real-world viability and performance. These projects will provide valuable data on long-term durability, maintenance requirements, and overall lifecycle performance of mycelium-based building materials.
As the construction industry continues to seek sustainable alternatives, mycelium's unique properties and environmental benefits position it as a promising material for the future of green building. However, continued research, development, and regulatory support will be essential to fully realize its potential in mainstream construction practices.
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Alaneme, K. K., Anaele, J. U., Oke, T. M., Kareem, S. A., Adediran, M., Ajibuwa, O. A., & Anabaranze, Y. O. (2023). Mycelium based composites: A review of their bio-fabrication procedures, material properties and potential for green building and construction applications. Alexandria Engineering Journal, 83, 234–250. https://doi.org/10.1016/j.aej.2023.10.012
Bitting, L. (2022). Applications of mycelium-bound composite materials in digital fabrication: Challenges and opportunities. ETH Zurich.
Dharmadhikari, A. (2024, May 16). Unearthing the fungal fortune: Mycelium market poised to surpass $5.18 billion by 2032. Medium.
Filipeboni. (2024, February 15). Building the Future: How Mycelium is Redefining Sustainable Construction. UGREEN.
Alemu, D., Tafesse, M., & Mondal, A. K. (2022). Mycelium-Based Composite: the future sustainable biomaterial. International Journal of Biomaterials, 2022, 1–12. https://doi.org/10.1155/2022/8401528
Zhang, M., Zhang, Z., Zhang, R., Peng, Y., Wang, M., & Cao, J. (2023). Lightweight, thermal insulation, hydrophobic mycelium composites with hierarchical porous structure: Design, manufacture and applications.