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The success of this integration will introduce architects and those in the construction industry to the potential of biomaterials, specifically mycelium biomaterials, and pave the way for greater research, development, and eventual implementation of biomaterials with no significant drop in quality or raise in price, and, in fact, a greater focus on environmental and human health, and a better world for everyone living and everyone who comes after us.

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This essay was composed in October 2024 and uses MLA documentation.

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Introduction

When I was young, I enjoyed exploring the expanse of land around my grandfather’s house. His house lies alone on the summit of a hill at the end of a secluded drive that abruptly turns from the small town nearby and leads only to his home. Inside, large picture windows look out at the breathtaking Southern Utah landscape on all sides, but all you can see is junk if you look down. My grandfather had built the house himself and had neglected to haul away the unused materials at the end of the project, likely to save costs. Instead, he scattered the junk and waste from the project around his house.

Along with the beauty of the surroundings, that was exactly why my cousins and I loved exploring the land around his house. To a child, such construction junk (whole packages of rusted nails! splintered wood! broken glass!) was full of opportunity and fun, but as I look back, I shudder to think of the multiple ways my siblings, my cousins, and I could have gotten hurt. I also shudder to think of how the hillside, which was otherwise resplendent with yucca, juniper trees, and the occasional deer, was marred by artificial materials, such as slowly oxidizing metals and shattered glass, that released toxins into the environment, injured people and animals, and otherwise scarred the landscape.

This experience was the first I had with construction waste and environmental degradation, but dealing with construction waste is not an isolated or insignificant problem. Although I experienced it on a small but impactful scale, according to the United States Environmental Protection Agency (EPA), “600 million tons of C&D (Construction & Demolition) debris were generated in the United States in 2018, which is more than twice the amount of generated municipal solid waste” (EPA). The mass of waste produced in a year shows that construction waste, which can contribute to carbon emissions, contaminate the landscape, and harm people and animals, is a widespread, large-scale problem in America.

The construction industry is a significant source of carbon-intensive materials or materials made by processes that release large amounts of carbon dioxide into the atmosphere, such as concrete, steel, and plastics. This release of carbon dioxide is negative, as CO2 emissions are the primary cause of anthropogenic climate change. At the end of the life cycle of a building, these carbon-intensive materials are often used as aggregate or sent to a landfill. New materials are made through the same carbon-intensive processes, releasing more carbon emissions and exacerbating the problem of climate change. In 2018, “just over 455 million tons of C&D debris were directed to next use and just under 145 million tons were sent to landfills” (EPA). Although the reuse of roughly three-fourths of carbon-intensive C&D debris is more environmentally friendly than condemning the debris exclusively to landfills, the use of this debris for something other than their original purpose still necessitates the creation of new carbon-intensive materials for value-added purposes, such as for use as structural materials. Furthermore, the approximately 145 million tons of construction waste is still significant. To put this number in perspective, 145 million tons of construction waste is slightly more than the total amount of construction waste, “136 million tons,” produced in America in 1996 (EPA).

All this production of carbon-intensive materials, whether reused or not, has a weighty effect on the environment. According to the UN’s 2020 Global Status Report for Buildings and Construction, as quoted in Lewandowska et al., a group of Polish architecture and woodworking researchers, “[T]he construction sector is a significant driver of climate change, responsible for 38% of global energy-related CO2 emissions” (Lewandowska et al.). Anthropogenic climate change not only harms the environment through global warming, ocean acidification, and shifting geographic ranges of plants and animals, but it also directly harms the health of humans, especially since humans are also part of the environment. Not only is the sheer mass of carbon-intensive materials produced a problem, but their lack of biodegradability is a problem in and of itself, as it can cause, according to researchers from the Department of Construction Technology and Management at Ethiopia’s Dilla University, “soil contamination, water contamination, energy and natural resources consumption, environmental degradation, and landscape deterioration” (Tafesse et al.). It’s also worth mentioning that current paradigms within the construction industry also contribute to exacerbating the problem of excessive carbon emissions and negative impacts related to imperishability. Bitting et al., a group of researchers for the Zürich-based Institute of Technology in Architecture, points out that the construction industry’s “current linear economic model of ‘produce, use, and discard'” directly contributes to the construction industry producing large amounts of carbon-intensive materials that later become industrial waste and harm the environment through leaching and other non-biological forms of breakdown and degradation (Bitting et al.).

To help solve the multifaceted problem of reducing CO2 emissions and environmental impacts in the construction industry, materials that biodegrade or are reusable should be implemented into the buildings and structures that are being used now and retrofitted into buildings that have been built in the past. Some examples of materials that are both non-carbon-intensive and biodegradable are biological materials, which are “material(s) derived from, or produced by, biological organisms like plants, animals, bacteria, fungi and other life forms” for the usage of humans, as stated in an article by the Penn State Department of Agricultural Economics, Sociology, & Education (“What Is a Biomaterial?”). Well-known examples of biological materials already being used as a replacement or supplement for traditional materials include “mass engineered timber (MET) and engineered bamboo composite (EBC)” (Bitting et al.). One of the most promising yet underutilized types of biological materials is biomaterials derived from mycelium.

Mycelium Bioproducts

Mycelium is the main body of a fungus. While mushrooms, which serve as the fruiting bodies (the reproductive part of the fungus), are visible and aboveground, mycelium is a rootlike structure of branching hyphae underground that grows and takes in and transports nutrients. It binds tightly to the substrate and grows on top of and inside. It can demonstrate different properties based on the substrate type, the fungal species, and other factors. A mycelium biomaterial is a selectively grown mass of hyphae within a specific substrate, with external variables carefully controlled to produce properties useful to humans, such as heat and sound insulative properties. Figure 1 demonstrates this structure and shows one of the current uses of mycelial biomaterials: biodegradable packaging (“Packaging”).

In recent years, there has been increased interest in using mycelial and other types of biocomposites due to the detrimental effect that materials such as plastics can have on the environment. As Eben Bayer, founder of Ecovative, a mycelium bioproducts producing company, points out in his TED Talk “Are Mushrooms the New Plastic?”, “In a single cubic foot of this material (styrofoam) – about what would come around your computer or large television – you have the same energy content of about a liter and a half of petrol” (Bayer). This comparison highlights how energy and carbon-intensive plastics and other conventional materials can be. Bayer then points out, “[M]ycelium is an amazing material, because it’s a self-assembling material,” meaning that instead of pouring energy, in the form of fossil fuels or otherwise, into this material in its manufacture, it’s naturally occurring biological nature means it grows by itself, if given sufficient feedstock (Bayer). Biomaterials made out of mycelium, timber, bamboo, and many other natural materials are being researched and developed to replace environmentally unfriendly materials, such as plastics and foams, in various industries, such as architecture, fashion, and packaging. Acoustic panels are one specific example of furnishing that can be replaced by mycelium biomaterials, a type of biodegradable material at the end of its life cycle, with no drop in quality and a comparable price to non-mycelium products. Mycelial biomaterials should be integrated into the construction industry as acoustic panels or, in the future, as a concrete supplement or replacement to reduce construction waste and pollution.

Acoustic Panels and Their Significance

Acoustic panels are made of a sound-absorbent material and are typically covered with a fabric with compatible auditory properties. They can block sound from escaping a space and enhance the clarity of sound within a space. They can be used in offices, concert halls, meeting rooms, or a wide variety of places where controlling the volume and the quality of sound produced is important. Although their manufacture is not a large contribution to the release of CO2 emissions, being able to address all materials and furnishings involved in the construction industry is essential to minimize its carbon emissions. Starting with replacing smaller furnishings and materials with biodegradable and/or reusable options will increase familiarity in the construction and architecture industry with alternative materials and their properties and will help lead to larger replacements and material substitutions further along the line. In Lewandowska et al.’s survey of fifty architects, “almost all architects (surveyed) believed that ecology has an impact on shaping contemporary architecture,” but “only 40% of the surveyed architects had heard about using MBC (mycelium-based composites) as a building material” (Lewandowska et al.). Although this lack of knowledge about mycelium materials and their uses among architects, let alone the general public, could be seen as a barrier to integrating said material into construction and architecture workflows, it also highlights an opportunity. This research highlights the gap between the number of architects considering ecological factors in their builds and those who know about mycelium-based composites. This material can help them reduce carbon emissions when manufacturing building materials and prioritize ecological factors in their builds. This implies possible market growth of mycelial materials in architecture that can be facilitated by the use of mycelial bioproducts in specific areas of architecture as pilot products, such as acoustic panels, and later, the expansion of the role of mycelial bioproducts due to architect familiarity and advances in research into mycelial biomaterial applications and properties.

Properties

Mycelial biomaterials are an ideal starting point for replacing carbon-intensive products with less carbon-intensive alternative materials. Mycelium can be shaped into a wide variety of forms by being grown in molds or 3D printed and can be engineered to have diverse sets of properties. When considering replacing conventional acoustic panels with mycelial biomaterials, engineering for a high sound absorption coefficient at different hertz frequencies is essential. The sound absorption coefficient measures the amount of sound absorbed by a material, which varies within a material depending on the hertz of the sound being absorbed. In a study by Walter and Gürsoy, researchers from Penn State University’s Department of Agriculture, mycelium grown with a substrate of shredded cardboard samples had the same sound absorption coefficient as a commercially available polypropylene acoustic panel (0.42), showing that it could effectively replace that product and similar products (Walter and Gürsoy).

Structural integrity is another important property for integrating mycelial bioproducts as acoustic panels. According to Gezer et al., researchers associated with Karadeniz Technical University, “[T]he fiberboards produced from fibers inoculated with Ganoderma lucidum (the reishi mushroom) and incubated for 30 days had higher mechanical properties compared to other test fiberboards” (Gerzer et al.). This example shows that mycelial biomaterials made with specific substrates and fungi species can have mechanical properties comparable to those of materials already used in industry, such as strength. Integrating mycelial bioproducts will help with decarbonization in the construction industry without a drop in quality from poorer acoustic and structural properties and pave the way for increased integration of biomaterials in the industry.

Research and Future Applications

Additionally, mycelial replacements and supplements for concrete are currently being developed. Exhibitions, such as Hy-Fi, a towering structure made majorly from mycelium bricks by a design studio, The Living, showcase mycelium’s potential as a load-bearing material. According to Arup, a British architecture firm that helped with the structural engineering of the mycelial structure, “The final structure comprises 10,000 organically grown bricks that easily carry their weight to the 40ft height,” and “the resulting structure can resist over 65 mph gusts” (“Hy-Fi”). This design shows mycelium bricks’ strength in a structure, especially when combined with good structural engineering practices. However, the ability of the lightweight bricks to hold up other lightweight bricks in specific conditions doesn’t immediately translate into using mycelium bioproducts as general structural elements. Research into helping apply mycelium’s weight-bearing properties into more general applications and increasing these properties so it can hold heavier loads is ongoing.

At the University of Utah, a biological engineering team led by Dr. Erika Espinosa-Ortiz has been trying to apply mycelium to repair cracked concrete. The team wants to use mycelium’s branching structure, the property that allows it to bind to a substrate, to act as a scaffold for biocalcification, or, in other words, to act as a scaffold for calcium carbonate production through biological factors. This scaffolding would be achieved either through the fungi directly producing calcite or bacteria in the fungi producing calcite on the fungal structure. This process would produce a mineral structure to increase the concrete’s strength and integrity in the areas where the concrete is cracked, allowing it to “heal.” According to Viles et al., a group of researchers working for the University of Montana, “living cells within ELMs (biomineralized engineered living materials) can enable additional desirable functionalities to these materials, such as regenerative properties, environmental responsiveness, or self-healing” (Viles et al.). Additionally, concrete is a very carbon-intensive material, so replacing or supplementing it is one of the many ways mycelial materials could be integrated into the construction and architecture industry to help the environment and minimize carbon emissions.

Barriers

Mycelium biomaterials are currently more expensive than non-mycelial products in most applications due to difficulties with large-scale manufacture and integration into existing economic models. Mycelium products are highly variable in properties based on the fungal species utilized, the substrate the fungus is grown in, humidity, temperature, and other environmental factors (Huang et al.; Bitting et al.). While this variability can allow for greater customization of properties, it can also make it hard to ensure consistent properties across a batch made in a large-scale factory. To ensure that fungal growth and properties are consistent in large batch production, more extensive monitoring of the products and the environment would occur than in a similar batch of a competitive product.

Another difficulty in scaling mycelial product production up is that larger mycelial bioproducts have differential growth throughout the exterior and interior. This is because the exterior of the mycelial product will develop a ‘skin’ where it is exposed to air. In smaller biomaterials, this doesn’t cause many problems, but in larger ones, the ‘skin’ can restrict airflow into interior portions of the product, making it difficult for the mycelium to grow there. As Le Ferrand, a researcher for Singapore’s Nanyang Technological University, reports, this lack of growth leads to inconsistent properties throughout the material. Mycelium’s biodegradation rate can also lead to inconsistent properties throughout the material and inconsistency over time. This inconsistency leads to difficulty utilizing mycelium in applications that require consistent properties throughout the material and over time, such as structural applications. The lack of public knowledge of mycelium biomaterials, difficulties with scaling production up and making production economically viable, and differential properties within these biomaterials are the main barriers to integrating mycelium biomaterials into architectural applications.

Rebuttal

In keeping the potential problems and barriers to application in mind, a pattern emerges: the main barrier to mycelial biomaterial integration is that we haven’t done it yet, accounting for the lack of large-scale manufacturing, material standardization, and lack of public and market knowledge of the material. It is exactly the validity of these barriers that shows why mycelial integration is so important. Lack of market knowledge of mycelial biomaterials is not an insurmountable obstacle; it is a symptom of the relatively recent creation and research into mycelial biomaterials and can be solved through the integration of pilot material replacements, such as acoustic panels, with no drop in quality or significant price raise. These innovations will introduce mycelial biomaterials to the market and pave the way for more ambitious material replacement or supplement in the future, such as using the biological properties of mycelium to create self-healing concrete or other structural applications.

The significant variability in properties allows for many potential applications for mycelial biomaterials. When reviewing different properties of mycelial biomaterials made with different substrates and fungal species, Huang et al., researchers for the University of Sydney, conclude that, “Overall, these findings demonstrate the potential and versatility of mycelium-bound composites in sustainable construction applications” (Huang et al). Furthermore, increased standardization of properties within a single material may come from the use of 3d printing and other types of additive manufacturing to produce mycelial biomaterials.

Conclusion

Although the integration of mycelium biomaterials as acoustic panels will not immediately solve problems with construction waste, as it is a reasonably minimal intervention, the use of mycelium biomaterials as acoustic panels is a perfect pilot usage: it has equal insulative and structural quality to acoustic panels already on the market currently (dissuading people from the belief that biomaterials are naturally inferior) and it has a similar price to products already on the market. I believe that the success of this integration will introduce architects and those in the construction industry to the potential of biomaterials, specifically mycelium biomaterials, and pave the way for greater research, development, and eventual implementation of biomaterials with no significant drop in quality or raise in price, and, in fact, a greater focus on environmental and human health, and a better world for everyone living and everyone who comes after us. Every step we take to replace carbon-intensive construction materials that are minimally reusable, produce pollution in their production, and are biophilic is a step toward a future with increased ecological and human health.

Works Cited

Bayer, Eben. “Are Mushrooms the New Plastic?” TED, July 2010, https://www.ted.com/talks/eben_bayer_are_mushrooms_the_new_plastic?subtitle=en.

Bitting, Selina, et al. “Challenges and Opportunities in Scaling up Architectural Applications of Mycelium-Based Materials with Digital Fabrication.” Biomimetics, vol. 7, no. 2, Apr. 2022, p. 44. DOI.org (Crossref), https://doi.org/10.3390/biomimetics7020044.

EPA. “Sustainable Management of Construction and Demolition Materials | US EPA.” US EPA, 22 Aug. 2018, www.epa.gov/smm/sustainable-management-construction-and-demolition-materials.

Gezer, Engin Derya, et al. “Physical and Mechanical Properties of Mycelium-Based Fiberboards.” BioResources, vol. 19, no. 2, 16 Apr. 2024, pp. 3421–3435, https://doi.org/10.15376/biores.19.2.3421-3435. Accessed 22 Nov. 2024.

Huang, Zicheng, et al. “Variations in the Properties of Engineered Mycelium-Bound Composites (MBCs) under Different Manufacturing Conditions.” Buildings, vol. 14, no. 1, Jan. 2024, p. 155. DOI.org (Crossref), https://doi.org/10.3390/buildings14010155.

“Hy-Fi Reinvents the Brick.” Arup.com, Arup, 2024, www.arup.com/news/hy-fi-reinvents-the-brick/.

Le Ferrand, Hortense. “Critical Review of Mycelium-Bound Product Development to Identify Barriers to Entry and Paths to Overcome Them.” Journal of Cleaner Production, vol. 450, Apr. 2024, p. 141859. DOI.org (Crossref), https://doi.org/10.1016/j.jclepro.2024.141859.

Lewandowska, Anna, et al. “Mycelium-Based Composites: Surveying Their Acceptance by Professional Architects.” Biomimetics, vol. 9, no. 6, May 2024, p. 333. DOI.org (Crossref), https://doi.org/10.3390/biomimetics9060333.

“Packaging, Ecovative (Mushrooms, 2015).” Building Centre. 5 Sept. 2016, https://www.buildingcentre.co.uk/news/articles/packaging-ecovative-mushrooms-2015.

Tafesse, Shitaw, et al. “Analysis of the Socio-Economic and Environmental Impacts of Construction Waste and Management Practices.” Heliyon vol. 8,3 e09169. 26 Mar. 2022, doi:10.1016/j.heliyon.2022.e09169.

Viles, Ethan, et al. “Mycelium as a Scaffold for Biomineralized Engineered Living Materials.” Bioengineering, 6 May 2024. DOI.org (Crossref), https://doi.org/10.1101/2024.05.03.592484.

Walter, Natalie, and Benay Gürsoy. “A Study on the Sound Absorption Properties of Mycelium-Based Composites Cultivated on Waste Paper-Based Substrates.” Biomimetics, vol. 7, no. 3, July 2022, doi:10.3390/biomimetics7030100.

“What Is a Biomaterial?” Penn State Department of Agricultural Economics, Sociology, & Education, aese.psu.edu/teachag/curriculum/modules/biomaterials/what-is-a-biomaterial.