In Brief
Mycelium bricks are lightweight bio-composite blocks made by allowing fungal mycelium to grow through plant-based fibres or agricultural residues. The growing mycelium binds the loose material into a solid form, which is then dried or heat-treated. Mycelium composites may offer useful thermal, acoustic and environmental properties, but most current products are better suited to protected, non-loadbearing applications than to replacing conventional structural brickwork or concrete.
Material Definition
What Are Mycelium Bricks?
Mycelium bricks are biofabricated composite blocks in which fungal mycelium acts as a natural binding network. The mycelium grows through a loose substrate such as sawdust, straw, hemp fibre, corn residues, rice husks or other lignocellulosic material. As its microscopic filaments spread, they interlock with the particles and help form a lightweight solid composite.[1]
The term mycelium brick is commonly used online, alongside terms such as mushroom brick, mycelium block and fungi brick. These products are not necessarily bricks in the conventional masonry sense. Their composition, density, strength, moisture behaviour and intended use can differ substantially from fired clay bricks, concrete masonry units and structural blocks.
Mycelium itself is the vegetative network of a fungus. It is made up of fine branching filaments called hyphae. Although mycelium is sometimes described as the “root system” of a mushroom, it is more accurate to understand it as the wider fungal network from which a mushroom or other fruiting body may emerge.
Important Distinction
A mycelium brick is not simply compressed fungus. It is normally a composite made from fungal mycelium and a plant-based substrate. The final performance depends on both parts of the composite and on how the material is grown, pressed, dried, treated and protected.
Biofabrication Process
How Are Mycelium Bricks Made?
Production methods vary between researchers and manufacturers, but most mycelium composites follow a similar sequence. Differences in fungal species, substrate, moisture, incubation conditions, compression and post-processing can produce materials with very different properties.[1]
Select and prepare the substrate
Agricultural, forestry or industrial plant residues are selected and processed into a suitable growing medium. The substrate may be cleaned, pasteurised or sterilised to reduce unwanted biological competition.
Inoculate the material
A selected fungal culture is introduced to the prepared substrate. The fungal species and strain can affect growth rate, bonding, surface formation and the final physical properties of the composite.
Place the mixture into a mould
The inoculated material is placed into a mould or form. This allows the composite to be grown into a block, panel, tile or customised component rather than being cut from a larger manufactured sheet.
Allow the mycelium to grow
Under controlled temperature, humidity and ventilation conditions, the mycelium spreads through the substrate and binds its particles together. Growth time depends on the selected organism, material mix and production method.
Dry or heat-treat the component
The grown component is normally dried or heat-treated to arrest further growth and reduce its moisture content. This stage is important for stability, storage and subsequent material testing.
Finish and test the product
A component may be pressed, trimmed, machined or coated depending on its intended use. Its suitability should then be established through testing relevant to properties such as strength, water absorption, thermal performance, acoustics, fire behaviour and durability.
Building Applications
How Is Mycelium Used as a Building Material?
Mycelium-based materials are being investigated for several different roles within architecture and construction. Their most credible near-term uses take advantage of their low density, formability and porous structure rather than relying on them to carry major structural loads.
Research and early commercial development commonly focus on insulation, acoustic absorption, interior products, lightweight cores and temporary architectural elements.[2]
Thermal Insulation
Lightweight and porous formulations may provide useful insulating performance when supported by verified product-specific thermal data.
Acoustic Panels
Some mycelium composites can absorb sound, making internal acoustic panels and ceiling elements a plausible application.
Interior Fit-Out
Panels, furniture, display elements and decorative components can use the material without exposing it to severe external weathering.
Lightweight Core Material
Mycelium may form the inner core of doors, partitions or composite panels protected by a stronger external layer.
Temporary Architecture
Pavilions, exhibitions and temporary installations can provide controlled opportunities to explore grown building components.
Protective Packaging
Packaging remains one of the more established uses because it benefits from low weight, mouldability and a relatively short required service life.
Material Properties
How Do Mycelium Bricks Perform?
There is no universal strength, R-value, fire rating or water-resistance value for a mycelium brick. Material performance can change significantly with fungal species, substrate composition, particle size, density, growth conditions, compression, drying and surface treatment. Published research values should therefore not be applied automatically to a different product or construction system.[1]
| Property | Potential | Important Limitation |
|---|---|---|
| Weight | Mycelium composites can be substantially lighter than conventional masonry and concrete. | Low weight does not by itself establish structural capacity or durability. |
| Thermal | Porous, low-density composites may offer useful insulation performance. | Thermal conductivity and R-value must be established for the actual product and installed thickness. |
| Acoustic | Some formulations demonstrate useful sound-absorption characteristics. | Sound absorption is different from complete wall or floor sound insulation performance. |
| Mechanical | Density, pressing and natural-fibre reinforcement can improve compressive and flexural behaviour. | Most current composites remain unsuitable as direct replacements for structural concrete or conventional loadbearing masonry. |
| Fire | Some tested formulations show charring, reduced heat release or favourable behaviour compared with certain polymer foams. | A generic mycelium product should not be described as fireproof. Product and assembly testing remains essential. |
| Moisture | Coatings, denser surfaces and protected assemblies may reduce water exposure. | High water absorption, humidity sensitivity and outdoor durability remain significant development challenges. |
| End of Life | Some untreated formulations may biodegrade or disintegrate under suitable biological conditions. | Coatings, additives, contamination and local processing conditions can change the practical end-of-life pathway. |
Are Mycelium Bricks Waterproof or Fireproof?
These descriptions should not be applied generically. Some formulations can perform favourably in selected moisture or fire tests, while others may absorb substantial amounts of water or require protective treatment. The relevant question is not whether “mycelium” has one fixed property, but whether the particular product and complete construction assembly have been tested for their intended use.
Material Comparison
Are Mycelium Bricks an Alternative to Concrete or Clay Bricks?
Mycelium bricks are not currently a like-for-like substitute for conventional concrete, fired-clay masonry or engineered structural systems. These materials have different densities, strengths, moisture responses, expected service lives and methods of compliance.
The expression mycelium concrete is sometimes used informally, but most mycelium composites are not concrete. They do not rely on Portland cement hydration and generally behave more like a lightweight natural fibreboard, foam or biological composite than a dense cementitious material.
Their near-term value is more likely to be found where low weight, insulation, acoustic absorption, mouldability or renewable feedstocks are useful. Conventional concrete and masonry remain more established where high structural capacity, weather exposure, impact resistance or long design life must be demonstrated.
Mycelium Composite
Lightweight, biologically grown and potentially useful for insulation, acoustics, internal products, lightweight cores and temporary applications.
Conventional Masonry
Dense, standardised and supported by established structural, fire, durability, weatherproofing and construction pathways.
Practical Use
Can You Build a House with Mycelium Bricks?
Mycelium components have been used in experimental pavilions, prototypes and research-led architectural installations. This demonstrates that grown components can be manufactured, assembled and experienced at an architectural scale.
A permanent house creates a more demanding set of requirements. The building must remain structurally adequate, weatherproof, durable, safe in fire, thermally appropriate and maintainable across its intended life. Meeting those requirements involves the whole wall, roof, floor and junction system—not only the properties of an individual block.
A realistic near-term house application may therefore use mycelium inside a protected hybrid assembly—for example as insulation, an acoustic layer or a lightweight panel core—rather than relying on exposed mycelium blocks as the entire structural and weatherproof envelope.
Environmental Performance
Are Mycelium Bricks Low Carbon?
Mycelium composites may use renewable feedstocks, agricultural residues and relatively low-temperature biological growth processes. These characteristics create the potential for lower environmental impacts than some fossil-derived foams, synthetic boards or energy-intensive products.
That potential should not be translated automatically into claims that every mycelium brick is carbon neutral, zero carbon or environmentally superior. The result can be affected by substrate sourcing, sterilisation, electricity, heat used for drying, transport, manufacturing losses, coatings, replacement frequency and the actual end-of-life route.
A credible environmental comparison should use a defined Life Cycle Assessment, product-specific environmental data or an appropriate embodied carbon assessment. Biological origin alone does not establish whole-life environmental performance.
Architectural Case Study
Hy-Fi and Mycelium Architecture
One of the best-known architectural demonstrations of mycelium bricks is Hy-Fi, designed by The Living for the 2014 Young Architects Program at MoMA PS1 in New York. Its organic blocks combined corn-stalk residues with mycelium and were grown in moulds through fungal activity.[3]
The installation demonstrated that biofabricated components could be produced and assembled into a large public architectural form. It also helped make mycelium architecture visible beyond laboratories and small-scale product experiments.
Hy-Fi should nevertheless be understood as a temporary, purpose-designed installation rather than proof that generic mycelium bricks can replace approved structural masonry in permanent buildings. Its architectural significance lies in demonstrating a new manufacturing and material concept, not in establishing a universal construction system.
Australian Context
Can Mycelium Materials Be Used in Australian Buildings?
Mycelium-based construction materials are an active area of Australian research. Work at institutions including the University of Technology Sydney and the University of Western Australia is exploring locally available waste streams, insulation, passive-cooling components, boards, blocks and hybrid material systems.[6][7]
Research activity does not mean that all mycelium products are automatically suitable for regulated building work. Under the National Construction Code, building materials and products must be fit for their intended purpose and supported by appropriate evidence of suitability.[4]
The evidence required depends on how the material is used. Relevant matters may include structural capacity, fire performance, weatherproofing, moisture behaviour, thermal properties, acoustic performance, durability, health considerations, installation and compatibility with the surrounding construction.
Where a proposed use is not covered by an applicable Deemed-to-Satisfy pathway, a project-specific Performance Solution may be needed. The proposed solution must still satisfy the relevant NCC Performance Requirements using accepted Assessment Methods and appropriate documentation.[5]
Australian Design Implication
Generic research figures should not be used as though they are certified values for a proposed product. The evidence must relate closely enough to the actual material, manufacturing process, dimensions, installation method, construction assembly and intended exposure conditions.
Practical Conclusion
What Is the Real Potential of Mycelium Bricks?
Mycelium bricks are a promising biofabrication pathway, but they should not be presented as a universal replacement for concrete, masonry or conventional building products. Their value is strongest where low weight, insulation, acoustic absorption, renewable feedstocks, custom-grown forms or designed biological end-of-life pathways are important.
Wider construction use will depend on improving durability, moisture resistance, manufacturing consistency, product testing, standardisation and regulatory evidence. The future may therefore involve hybrid systems in which mycelium provides a specific function inside a stronger and more durable building assembly.
Frequently Asked Questions
Mycelium Brick FAQ
What are mycelium bricks made from?
They are normally made from fungal mycelium grown through a plant-based substrate such as sawdust, straw, hemp, corn residues, rice husks or other agricultural and forestry by-products.
Are mushroom bricks and mycelium bricks the same thing?
The terms are often used interchangeably. Mycelium brick is more technically accurate because the binding network is formed by fungal mycelium rather than by the mushroom fruiting body itself.
Are mycelium bricks stronger than concrete?
No general evidence supports treating mycelium composites as stronger than conventional structural concrete. They can be much lighter, but their compressive strength is generally lower and varies considerably between formulations.
Are mycelium bricks waterproof?
Not inherently. Water absorption, humidity sensitivity and outdoor durability are important limitations. Protective coatings and assemblies may improve performance, but they can also affect biodegradability and end-of-life options.
Are mycelium bricks fireproof?
They should not be described generically as fireproof. Some formulations demonstrate favourable fire behaviour, but the performance of the specific product and complete construction assembly must be established through appropriate testing.
Are all mycelium products biodegradable?
Not necessarily. Biodegradability depends on the substrate, manufacturing process, additives, coatings, contamination and the conditions available at the end of the product’s life.
Can mycelium bricks be used in Australia?
Potentially, provided that the proposed product and construction system are fit for purpose and supported by evidence relevant to their intended use. A Performance Solution may be required where an applicable Deemed-to-Satisfy pathway is unavailable.
Related Building Performance Resources
Understand the Wider Environmental Impact of Building Materials
Technical Sources
- Aiduang, W. et al. (2024), “A Comprehensive Review on Studying and Developing Guidelines to Standardize the Inspection of Properties and Production Methods for Mycelium-Bound Composites in Bio-Based Building Material Applications.” Biomimetics, 9(9), 549.
- Voutetaki, M. E. et al. (2024), “Natural Fiber-Reinforced Mycelium Composite for Innovative and Sustainable Construction Materials.” Fibers, 12(7), 57.
- Museum of Modern Art, “The Living. Mycelium Brick. 2014.” MoMA Collection.
- Australian Building Codes Board, “What Are the Requirements for Compliance and Conformance?” National Construction Code.
- Australian Building Codes Board, “Understanding the NCC.” NCC compliance pathways and Assessment Methods.
- University of Technology Sydney, “Mycelium-Based Blocks Could Be the Future of Construction.” UTS research overview.
- University of Western Australia, “Bio-Based Materials Design Lab.” UWA research program.
Last reviewed: June 2026
This article provides general information about an emerging material category. The suitability, environmental performance and regulatory acceptance of any proposed mycelium product must be assessed using product-specific evidence and the requirements applicable to the project.
