Finding Sustainable Alternatives to Traditional Building Materials

I am professionally trained as an architect, registered and practicing in Nairobi. I was among 10 fellows from across the continent who were involved in a fellowship program at the African Design Center, led by MASS Design Group. In that fellowship, we were given support and resources to research the things that we were interested in. Now, I have always been interested in materials in architecture – especially using materials and technologies that are locally available and pushing the limits with these materials, seeing how much we can achieve. During that fellowship, I saw all of this interesting research into fungi.

I work in Nairobi, but this fellowship was in Kigali, Rwanda. And it happened that in Kigali, there is one of the biggest mushroom-growing farms in East Africa. I realized that this was a good opportunity and so I spent some time with them, maybe two weeks, just in their factory seeing what was happening and how they grow their mushrooms. To me, it looked like quite a simple process, so I started doing the same in our pantry – doing tests, putting them in water bottles and food containers, growing them in different shapes and forms, pressing them with a car jack, just trying to see what strengths I could achieve. At the end of the fellowship, I had even tried making a big panel with corrugated sheets, seeing how far I could take it before they would break.

Now, Kenyans are known for being entrepreneurs, and so of course, when I came back to Kenya I started pitching the idea in several places. Back then it was not really a business, just the idea that you could make building panels using agricultural waste and mushroom mycelium. Most people thought it was crazy – “How can you build with mushrooms!?” – and you try to explain that that’s technically not the case, but that’s what everybody hears.

We pitched a number of times, until one day, Habitat for Humanity was interested in what we were doing. They got us some catalytic funds and we engaged with some professors from the government through the Kenya Industrial Research and Development Institute (KIRDI), and we partnered with them for product development.

That is when we got seriously into developing the idea into an actual building material. At the time, we thought we could do modular suspended ceiling panels, but in the lab, as we were doing the research we realized that insulation is a lot easier as a market entry product.

Today, the way MycoTile is set up with our mycelium and agricultural waste is to create a whole portfolio of different building materials. Our insulation is what is in the market and ready to go, but behind the scenes in our lab, we are making building blocks, accessories like lampshades and pen holders, wall tiles and floor tiles and other things like that.  

We can take in most types of agricultural waste – including sugar cane bagasse, coffee husk, corn cobs, coconut coir, rice husk and straw – sterilize it to remove pathogens, and then we introduce mushroom spawn or mushroom roots. We allow those roots to grow through the agricultural waste fiber substrate and they effectively bond it all together into a composite. This composite, depending on how you treat it, can become different building materials. You can use it as it is, retaining that spongey and fluffy texture, so it becomes very good insulation. Or you can use a hydraulic press to make it more compact – this is how you can create medium-density fiberboard or strawboard materials. Or you can press it even harder to make a brick.

No matter what you make, the process is very similar: we pasteurize the waste, introduce the spawn, mycelium fibers grow through it and then we allow it to dry. It’s very easy to denature the mycelium; at temperatures of around 60 °C the mushroom mycelium is denatured. By the time the composite has become a building material, it is basically like wood – it is an organic material that is denatured and it cannot continue growing.

If you don’t denature the mycelium, then one day somebody might have a panel in their house and mushrooms will start popping out of it. It could be an interesting idea, having food coming out of your walls, but I think for most people it would be a bit creepy! For some clients, maybe with decorative accessories or a lampshade that you could moisten and it will start growing edible oyster mushrooms, that’s not a bad thing and we can leave it denatured.

But largely, what we do is stop the mushrooms from popping. Because the mushrooms aren’t able to pop, their fibers start looking for a place where they can pop somewhere else. That process of forcing them to look for new areas to pop is what gives us the density we want.

Depending on what we have as raw material, our process may change a bit. For example, if we are using sawdust, we have to add a basic substance to reduce the acidity because the mycelium will not do very well in that environment. And if we are working with sugar cane bagasse, then we might add straw. Some factories process their sugar cane bagasse to be very short lengths and you might not be able to make a very big panel when your substrate fibers are only two inches long. So, the straw can give us some extra length and strength.

Concrete products and any petroleum-based products contribute significantly to greenhouse gas emissions, which of course leads to climate change. Mycelium-based materials are a completely organic substitute for materials that could otherwise be harmful to the environment, such as plastic-based insulation materials. At the end of a building’s life, these mycelium materials are also completely compostable. So you can compost it, harvest the products, make another panel, compost it again and the cycle continues – it’s circular.

Mycelium can be used to bond with waste that otherwise would have gone to landfills and would have been releasing carbon. So we are capturing that carbon in bulk in building materials so it can be stored in buildings. The process of growing mycelium itself also captures a bit of carbon, which we can track.

For the more practical aspects, mycelium contains chitin, which is a natural fire retardant. So when you try to burn it, our product just chars – meaning a fire will not catch and burn through to the next room.

The housing deficit is a major problem. In Kenya, where we operate, the deficit is at 80% – only 50,000 housing units are being supplied against a demand of 250,000 units per year. We cannot continue with brick and mortar because they have not solved the problem for so long –  so we have to try some more radical materials and see how they fit in.

I think this is where, as MycoTile, we are trying as much as possible to create a whole portfolio of products. If you can get a building block, tiles and insulation that are available locally and are affordable, I think we will penetrate the market a lot easier.

Another major issue is employment. This comes as more of an after-effect for us, as we are a manufacturing company, so automatically creates employment. But even just for availability, I think that insulation is not even really considered by the average local person. Our temperatures are not too extreme around here, so people can survive, but it’s not necessarily the best. Other insulations, like rockwool, are generally considered to be more of a high-end material. But now we’re creating a very accessible and easily available product for people that does not need to be imported.

We have also been doing a bit of research to see what we can do for internally displaced people, such as creating quick-installation materials that at the end of their life can go straight to composting so that they won’t be a target for theft or vandalism.

These are some of the challenges that I think mycelium-based products are trying to solve. But essentially we are trying to answer this big question of how we can have materials that are more sensitive to nature, to be more conscious of how we are impacting the Earth.

Another major barrier would perhaps be statutory issues. There is no standard for organic-based materials like this, as there is no prior standard to measure against. With the Kenyan Bureau of Standards, we are essentially being asked to create a standard and then present our materials to be tested against it to see if it works and counter-check our claims. This means that for the clients who are very specific about standards, we are not able to address all of their concerns at the moment.

So the standards have been a bit of a challenge, getting them right, but even getting a lab to do things like a lifecycle analysis has been difficult because creating an environment where we accelerate the life of the product to see how it behaves has not been easy.

More informally, in our industry, people want to do a “knock test”. If the building doesn’t feel solid enough when they knock on it, then it is not a building material. People believe in solid materials like concrete, where you can hit it and hit it. Our material is very light, and for lack of a better word, quite “flimsy” in the knock test. But that is why we are primarily using it for insulation.

Naturally, the building industry is very conservative, so introducing a new product is not easy. There is a market leader in interlocking stabilized soil blocks in Kenya called Makiga Engineering – it took them 10 years to become fully accepted and their material is very solid! So we are aware that the journey will be a bit slow, but we will get there. The research work has been fantastic and we are always discovering new things. Mycelium gives you something new every day!