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FROM WASTE TO BIOMATERIAL - Developing mycelium and wastebased materials for the building industry

Denne idé er en del af The Circular Construction Challenge – Rethink Waste

Søren Jensen Rådgivende Ingeniørfirma
Søren Jensen Rådgivende Ingeniørfirma
8. oktober 2018

Below is an extract from the enclosed PDF file. All text below is also available in the PDF


Discussions about circular building design often focus on recycling technical building components and optimisation of production processes. However, to truly embrace regenerative building design also we need to develop mass-produced biomaterials that 1) are renewable and biodegradable, 2) Can replace current building materials with high environmental loads and 3) Can eliminate problematic waste streams. We believe developing mycelium and waste-based biomaterials is one way to achieve this.


This project idea is based on a material experiment conducted at Søren Jensen Consulting Engineers in the spring and summer of 2018. The experiment sought to answer whether it is possible to produce biological building materials on waste produced at our own offices and turn this into our annual DHL relay race pavilion.

We learned a lot from this experience about the production process and how different growth media effect the resulting product’s density and this inspired new ideas for applicability of this type of biomaterial. The experience has also verified our assumption that mycelium is an incredible material with a vast and unexplored potential.


We believe mycelium and waste-based biomaterials have great market potential both nationally and internationally. Through co-creative processes we hope to develop new biomaterials for the building industry.

By participating in the Circular Construction Challenge, we hope to 1) Complete material tests on different combinations of different mycelium species and waste types, 2) Identify the uses of mycelium grown on different types of waste, and 3) Evaluate how these might be used in buildings.

To succeed we need collaboration with a broad field of partners from biologists, technical laboratories, building product manufacturers, waste handlers, municipalities, suppliers of organic material and mycelium spores. Enclosed in this document we have assembled declarations of interest from relevant stakeholders.


Through the Circular Construction Challenge, we aim to investigate the potential of mycelium and waste-based building materials further and provide product manufacturers with the technical knowledge required for them to adopt mycelium and waste into their manufacturing processes. The outcome will be a catalogue of material recipes and test results for each recipe.


We hope this will bring us closer to a future marketplace where we can utilise mycelium and waste-based materials in our building projects. This will bring us closer to the realisation of regenerative buildings.

It is not our goal to become product manufacturers ourselves. Through participation in the CCC we hope to facilitate the development of mycelium and waste-based building materials in a co-creative process with technical experts, building product manufacturers, material and waste suppliers.


To complete our mission to develop mycelium and waste-based biomaterials we need partners who 1) understand fungi biology, 2) understand how to cultivate fungi growth from organic waste, 3) can test the technical abilities of these new materials, 4) can provide sparring on product manufacturing processes, product legislation and implementation on construction sites and 5) can produce building materials.

We have researched the availability of this expertise in Denmark. It is our conclusion that, whilst we have experts within each field, we are entering unknown territory when developing mycelium and waste-based materials.


Fungi is a billion-year-old specie separate to plants and animals. The specie consists mainly of a body of mycelium - a giant root organism that lives underground. When exposed to light, mycelium produces eatable mushrooms.

Mycelium has developed an ability to chemically transform dead organic matter into new minerals. Through the use of enzymes, it replaces this matter and acts as the primary natural recycler that eliminates waste in the natural world and transforms it into nutrients. In this process the spores bind the matter together as a natural glue to a substance that is very resilient and resistant to water and fire.

Mycelium also has an ability to fight and eliminate other pathogenic bacteria and spores, which is why for instance it has been used to develop penicillin. Therefore, once a substrate has been successfully colonized mould and other harmful spores cannot easily grow.

Mycelium spores are able to transform organic waste into new natural materials by consuming its nutrients in a natural process. This process can be used to grow fruits (mushrooms) or to grow spores that bind the growth matters together and increases the strength of the matter. When dried the fungi dies and water evaporates. This lightens the material and stops the growth. This results in a strong, shapeable and light-weight biomaterial that combines binding of natural fibres with evolutionary resilience. This results in a set of attractive properties which makes for an interesting building material.


It is our experience that the characteristics of the finshed material is dependent on the characteristics of the host material. Materials based on wood or plant fibres such as hemp will become stronger than materials based on food waste etc. The density will also influence the tensile and yield strength, fire resistance, sound absorption as well as thermal conductivity. By investigating how different mixtures of waste materials, virgin materials and mycelium spores behave, it is possible to uncover how different waste streams can be transformed into ideal recipes for new biomaterials and hybrid materials for the building industry. The selection and mixing of waste therefore become a matter of design depending on required material qualities of the finished products.

As mycelium grows in the substrate it will transform into any 3D shape it resides in. If put in inorganic molds that is not transformed and therefore acts as a barrier and formgiver. This makes it applicable for use in both additiative elements as well as complex and detailed geometry. Mycelium organisms grows a protective skin on the surface that is exposed to oxygen. This skin contains the primary attributes of fire and water resistance but also creates a clean white surface which, depending on the filling and pressurisation of matter in the formwork, can become extremely smooth. The material can be polished and died using natural and examples of this can be found in fungi-based textiles that assimilate leather.

Based on our research and preliminary pavilion experiment, we have concluded that mycelium-based materials have a number of technical abilities that makes it very interesting to the building industry:

Adaptability to growth environment, Geometrical shapeability, Non-toxic and ability to ’eat’ toxins

Low thermal conductivity, Fire-resistance, Water resistance, Absorption of noise, Low embodied, impact, Bioproductive and biodegradable.


The following types of waste are assessed to be relevant for mycelium and waste-based biomaterials; Timber and sawdust, Agricultural waste, Biodegradable plastics, Thermal insulation, Textile, Paper and cardboard, Food waste, Plastics?, Algae?, Seaweed?

The size of the fraction reduced depends on the quantity of products produced. The ratio of waste to spore influences primarily the duration of growth in the colonization of the substrate. It is our estimate that the ration between substrate (waste) and spores would generally be 80-95% dead organic matter, and 5-20% spores. and once the material is finished 100% of this has been transformed to a new material.

The size of the reduced waste fraction depends on which types of waste are deemed applicable in the production of different types of building materials. Whilst stone wool, glass wool, biodegradable plastic, slurry and food waste are probably excellent growth material for acoustical panels and insulation materials. Timber and cardboard are expected to be more applicable in the production of façade cladding.

The spores need a moist material to grow in. This means that it is possible to upcycle cardboard and paper that is too wet or which is mixed with other organic materials (e.g. faeces). This means that paper that was previously deemed unrecyclable could become recyclable. The spores are also able to grow in shredded timber that has a low burning value, which means that the product manufacturer should be able to purchase growth materials for a low price or even get most of the waste for free because it has no real value to the seller.


The mycelium and waste-based materials have the potential to replace conventional building materials who have a high environmental footprint from the production phase and at the end-of-life stage.

Examples of such products are; thermal insulation materials like stone wool and glass wool, acoustical panels produced with stone wool and/or cement-based wood wool, textiles produced with large water and energy consumption, timber, textile or cement-based façade cladding, structural load bearing elements (e.g. walls and membranes).


The actual CO2 reduction will need to be calculated as part of the CCC project. It will without doubt have a very low and potentially positive CO2 footprint depending on how it is calculated. The calculation will however depend on the final combination of materials to be used in different types of building products.


No. 1 No poverty: Mycelium and waste-based materials can be produ­ced at a low cost and they can be grown in remote locations using local waste and mycelium spores.

No. 3 Good health and wellbeing: The material has the potential to eat and neutralise polluted waste. The material will not contain any poisonous substances

No. 8 Decent work and economic growth: Mycelium and waste-based materials are applicable worldwide and has the potential to create new jobs and economic growth.

No. 9 Industry, innovation and infrastructure: Mycelium and waste-based materials are new innovative bionic materials that mimic nature and reduces the environmental footprint of the built environment

No. 11 Sustainable cities and communities: Mycelium and waste-based materials will enable a significant change in the environmental and societal sustainability of the built environment through a circular business model and a biologically grown material.

No. 12 Responsible consumption and production: Production of the mycelium and waste-based materials ensure responsible consumption by using regenerative materials and waste in the production of new bionic buil­ding materials. Environmental impact from the production process is very low. Some might argue that be eliminating landfill and incinerated waste the environmental foot print will be positive.

No. 17 Partnerships for the goals: Development of mycelium and waste-based materials requires collaboration between suppliers, product manufac­turers, construction clients, design consultants, contractors and waste management firms.


Planetary value; Biomaterials mimic nature. They are thus a part of natural systems in a way that inorganic materials are not. The material has the potential to reduce current and future waste sent into landfill and incineration from both the building, textile and food industries. Mycelium spores are not picky and poorly rated waste materials sent to landfill or incineration are used in the production of new biomaterials. Mycelium spores are regenerative, and the material will be biodegradable.

Societal value; Mycelium and waste-based materials ensure societal value through better use of planetary resources and reduction of the expected overall cost increases on conventional building materials. The material has the potential to eliminate waste which is currently sent to landfill or incineration – especially waste at the bottom of the waste hierarchy that no one currently has a use for. This will free up land and potentially reduce the release of toxins from landfills to the environment.

End user value; Construction clients get access to bio­materials with very little or no impact to the environment. The costs of produc­tion would be relatively cheap because the growth media and mycelium spores are relatively cheap.


The primary stakeholders involved in the value chain are visualised in the diagram. Value capture in the value chain will depend greatly on the outcome of the CCC project and which partners we will team up with. If the final product is a product from a building product manufacturer, the stakeholders who stand to capture most value will be material suppliers (i.e. manufacturers of mycelium spores, waste management firms and/ or building owners selling their materials) as well as the product manufacturers. Building owners and contractors may also be able to capture greater value if the products are cheaper than conventional building materials and the product manufacturer decides to forego the potential additional value capture.


Target market: We need to define our target market together with the rest of our CCC team. The result of the project should be applicable and relevant in building industries all over the world. Different countries regulate the building industry differently and the product will need to demonstrate compliance with local legislation. The initial target market should thus be markets where our industry partners know the legislation and how to document compliance.

This product will threaten existing business models and it will be very interesting to see who decides to apply to become a team member on the project.

Market potential: The market potential of the solution depends on which industries we are partnered with and whether the product cannibalises a current market for our partners or it helps them capture new markets. An analysis of the market size for mineral wools (stone and glass wool) shows that the global size of this market is estimated to be $12.0 billion by 2019. The analysis ascribes the growth in market value to an increase in acoustical panels in both existing and new buildings. Even a fraction of this market would make the development of bio-based mineral wool a lucrative investment.


One of the biggest barriers to market penetration is scaling of manufacturing processes whilst decreasing costs for market competitiveness. The process of transforming waste to new building products requires partners to aid in scaling several steps in production. This includes optimised growth environment, waste collection and preparation, formwork design, compacting of materials and heating.

Many of these steps can be automated which makes the process appropriate for offsite manufacturing in which efficient production lines can reduce labour intensity and costs. Using offsite manufacturing improves the value capture to production cost ratio and ensures a competitive sales price of the final building product. Using automated production and BIM models enables robotic or 3D printed moulds. The moulds can be designed as recyclable filaments or matter can be printed as fine biological substrates with no need for moulds.

As the primary production process is natural with little power requirement, it is also appealing to consider onsite manufacturing. This will provide new opportunities in terms of reducing environmental impact from transportation of building materials and enable design of building elements that will grow together once assembled and thereby eliminating need for joints and thermal losses in building envelopes. Onsite manufacturing will require transportable climate chambers powered by renewable energy sources. In the onsite scenario smaller onsite robotics could replace the assembly line and thus reduce labour costs on site.

Digitalisation of onsite or offsite fabrication will accommodate a business case that enable bespoke onsite manufacturing of biomaterials whilst decreasing labour intensity required for creating formwork based on detailed BIM models.


So far, we have been unable to identify any Danish experts in the field of mycelium and waste-based biomaterials. We have identified potential experts in individual fields that together enable the development of these biomaterials. These experts need to come together in a co-creative process which is why the Circular Construction Challenge is an optimum platform for the exploration of mycelium and waste-based materials. Some of these partners have filled out declarations of interest enclosed in the back of this document.


Figure 9 in the enclosed file illustrates the steps required to develop new mycelium and waste-based building materials. The CCC project will primarily focus on the top row of processes whilst preliminary discussions about the bottom row will be initiated in the end of the CCC process. Both rows of processes are vital to the development of the biomaterial and realisation of building products.

The top row focuses on the development of recipes and material tests whilst the the bottom row focuses on the investigation supply chain, large scale manufacturing and onsite application.


Our sketch for the partnership model is depicted in fig. 10 in the enclosed file. It consists of two layers of organisation. At the centre is a working group consisting of Søren Jensen Consulting Engineers, product developers, material suppliers, mycelium labs, material tests labs. Surrounding this organisation is an advisory board consisting of waste management firms, contractors, construction clients and relevant authorities. Søren Jensen will be responsible for facilitating workshops and coordinating the initial material tests whilst contractors and product manufacturers will end up with the ownership of building products or onsite construction processes.

The resulting knowledge about mycelium and waste-based materials will be anchored in the working group in the form of different recipes for biomaterials and concrete ideas and prototypes for further development with the product manufacturers.

Partners in the workgroup who do not stand to capture financial value from product sales will be rewarded through a royalty programme agreed upon by the different parties in the working group prior to the final submission in January 2019.


When engaging in co-creative processes we utilise an approach to design thinking developed at the Design School in Kolding. The approach structures processes into opening and closing stages and provides tools for how to explore and condense ideas. We have previously applied this approach on the development of a dialogue and prioritisation tool for sustainable decision-making processes. An initial process plan is sketched in figure 11 in the enclosed file. This will be revised after a project team is formali­sed in the beginning of December 2018.