Home » The future is fungus: Are we ready to grow home?

The future is fungus: Are we ready to grow home?

by Tim Clark
Fungus is found everywhere in nature, but the properties that make it such a successful organism could also see it become a versatile, eco-friendly building material.

Fungus is found everywhere in nature, but we mostly don’t see it. The properties that make it such a successful organism could also make it a versatile, eco-friendly building material. Tim Clark reports

Imagine being able to grow the walls of your home and take carbon out of the atmosphere at the same time.

It’s not as strange an idea as people may think. Timber-frame housing is standard across many countries and – with sustainably-sourced forests – can work as a low-carbon building material.

However one promising material could take the construction industry’s carbon revolution that one step further: Mushrooms.

Or to be more specific, mycelium – the root part of fungi – that promises not only to be a versatile and sustainable building material, it can even take CO2 out of the atmosphere by acting as a construction material.

“If you imagine the mushroom is the fruiting body, it’s almost like a tree and then underneath has a network of thousands of tiny filaments that in nature break down nutrients and plant matter,” says Evie Faure, senior commercial strategist at Biohm – a London-based firm that is leading the design and utilisation of mycelium as an innovative building material.

“Many of mycelium’s different functions in nature have only been discovered and tapped into in the past few years; we’ve started to realise that mycelium plays a pivotal role in ecosystems.

“The way that we work with mycelium is that we have a variety of strains that we harvest in the UK, we grow it in a controlled manner in labs.”

Natural material

Biohm was founded seven years ago by Dr Ehad Sayed, who patented a modular construction system that didn’t require the use of glues or adhesives. This idea quickly evolved into researching new materials, and looking at what was available in nature. The company has been working with mycelium for the past five years and now has a 20-strong team.

Mycelium works by breaking down organic matter and using the raw components to grow its own mass. In the natural environment, enzymes secreted by the hyphae (which are the individual filaments of the root structure) take decomposing material such as leaves or wood bark and break into smaller parts, this then feeds the fungi. This biological process means that waste food or agricultural products act as the food source for the mycelium.

The mycelium product can also be adapted to grow in different ways, such as at a different speed or structure by altering the substrate – or food – it is given. This allows for product differentiation.

Another key aspect of mycelium is that it can simply grow and grow.

In Oregon, in the United States, one species of fungi known as Armillaria ostoyae is estimated to cover up to 10 square kilometres – which would make it the largest single organism in the world by some margin. It is known locally as the ‘humongous fungus’, and is believed to weigh up to 35,000 tons.

Biohm are looking to capitalise on the simple fact that mycelium is a versatile material to work with, and are in the final stages of developing their insulation product.

“The way mycelium grows means it can be tweaked in many different ways,” Faure adds. “One of those is the way that it grows within a mould, so it can grow [in a mould or tray]. You can then stop the growth process and it forms an inert like-for-like panel to an EPS panel or similar.”

The product was showcased last year at Glastonbury Festival where Biohm were chosen to supply panels that were cut in a similar way to how set designers use foam or polystyrene to create sets to form a small stage.

Designed by Temple Design Studio and known at the festival as the “mycelium pavilion”, the installation was used to show how the product could be used in a number of ways – from structural insulation to the raw material for creative design of sets, lowering the use of materials such as plastics or polystyrene.

There is, of course, a huge way to go before mycelium can take its place among the average new build home, however the successful trial at the festival proved that the material could be scaled up in production.

Insulation

Apart from its ability to cut down carbon and grow naturally into a mould, two key properties make mycelium stand out as a potential construction material – its insulative properties, and its ability to withstand fire.

When it comes to insulation, mycelium grows and creates air bubbles as it weaves its filaments around a substrate, these air pockets help with sound-proofing and insulation qualities.

“The beauty is that mycelium acts as a kind of structure, a kind of glue or binding agent that attaches to anything around it. As it grows and consumes the substrate it forms these tiny air pockets allow for really great thermal conductivity properties,” Faure adds.

“Varying the growth methods, or substrates, or times, as well as changing the post-processing and pre-processing allows us to feed in different factors into the final products.

“In terms of [insulator] properties it performs really well compared to what is on the market.”

The product isn’t necessarily limited to construction. Biohm aims to bring products to several different markets. The main focus at present is the construction industry, however the company is looking to use mycelium in the fashion industry, or in furniture or toys.



It can take two weeks for a mycelium starter to grow to fill an insulation panel mould. The process isn’t as simple as taking mushrooms and turning them into walls; the company has a research department with a mycologist, molecular engineers, materials chemists, and development engineers.

“We do a lot of evolution strains, and take the strains [of mycelium] that we think will perform best at industrial scale for example,” says Faure.

“We are also beginning to use genetic engineering in some of our strains to achieve the properties that we want to achieve. Some [strains] create really interesting leathery materials, others insulator materials.

“If you imagine a batch process, you can do it on a large scale, such as a vertical farm but without the need for lighting. We’ve tried replicating the conditions it grows in nature, which is dark moderate temperatures.”

To fit with the different final product that they are looking to grow, Biohm have also looked at changing the genetic make-up of the mycelium organism it uses to allow it to focus on different properties.

One of these is to make the fungi “feedstock agnostic”, which means that it can grow on any organic material or waste product. This would allow a much greater degree of recycling of waste food, and help cut carbon emissions significantly if it was to be implemented at scale.

The future, where next?

Faure says that far from stopping at the insulation market, Biohm is looking to use a mixture of mycelium and other bacterial organisms to create a bio-substance that can break down and detoxify synthetic waste and plastic waste.

“This is really early stage research,” she says. “But we’ve had some promising results where plastics were no longer recognisable after three months of being in the swirl of microorganisms, which is really exciting.”

As a wonder material, mycelium has been one of the answers to the construction carbon conundrum, and it has been right beneath our feet all along.


Read next: Amazon supports new CIBSE guide on logistics decarbonisation

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