From mushroom spores to modern structures w/ Dr. Mercedes Garcia Holguera

Jen Hancock:

What if our homes could change like the seasons?

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Jen Hancock:

I’d like you to picture the perfect house for a warm breezy summer. Wide open patio doors lead onto a verandah, which encircles the whole building. There are Muskoka chairs, perfect for relaxing with a cold drink. You can smell the barbecue. A cool breeze blows across the nearby lake and through the open windows.

But as summer gives way to fall, which fades to winter, that cool breeze becomes a bracing wind and then a bone-chilling cold.

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Jen Hancock:

Your perfect summer home is damp and chilly. And in the rotting wood of your now useless verandah, mushrooms grow.

[music and rainstorm noises]

Jen Hancock:

Those mushrooms don’t stop growing. The stalks intertwine in a tight hug, and the caps expand until no air can pass through. Eventually your verandah is a corridor around the house, with a thick wall of fungus on its edge.

Your perfect summer home—which was open to the breeze—is now a tightly insulated winter palace. You are warm and snug inside the house, and you have a slightly cooler external area to keep food chilled.

And when summer comes, the mushrooms wilt away, fertilizing the ground around them. Your summer home returns, and the cycle begins again.

Jen Hancock:

This is Building Good. I’m Jen Hancock.

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Jen Hancock:

What I just described is kind of a fantasy. Or, maybe it’s more science fiction, because science fiction has a habit of occasionally eventually becoming reality. Today on Building Good, we’re talking to a researcher who is working to make that mushroom wall, or something very like it, a reality.

Dr. Mercedes Garcia Holguera and her team, at the University of Manitoba, have been developing mycelium-based, industrial-strength construction materials. Or, “mushroom bricks,” as they’re becoming known.

Dr. Mercedes Garcia Holguera:

What happens is that you are using a living organism. More specifically it’s mycelium, which is this part of fungi. You let it grow and colonize nutrient-rich substrates so that the mycelium acts as a cement and gathers and brings together all these other loose elements and turns into a brick or a panel.

Jen Hancock:

It’s not quite my sci-fi vision of a self-growing house, but it’s not far off.

Outside of construction, mycelia are being used in packaging—replacing materials like styrofoam and polyurethane. And now researchers, like Dr. Garcia Holguera, are looking at other use cases, like sustainable insulation.

Because mushroom bricks are naturally fire-resistant and can trap more heat than fibreglass, those fuzzy-looking white, green, or black fibres are carbon-neutral, eco-friendly, and non-toxic. And when placed beside each other, the bricks will actually bond together. Talk about a living wall.

I’m no mycologist, so I’m gonna assume you aren’t either. So here’s a little primer. In the life cycle of a mushroom, mycelia grow from the germinated spores of an adult mushroom. You can think of mycelia like the roots and tendrils of a young plant, exploring the substrate and consuming nutrients. And if you provide a substrate for it in the shape of a brick and let it grow, you’ve got yourself a mushroom brick.

Dr. Mercedes Garcia Holguera:

Basically, what you are doing is to feed the mycelium to let it grow. You wait for a certain time and certain growth conditions—temperature and humidity levels. And when the growth processes finish, you either kill the mycelium—and for that you have to put it in an oven and bring it to some high temperatures—or you can let it keep growing, in which case you will have the mushroom fruiting. And that’s when you have like the mushrooms that we are more familiar with.

Jen Hancock:

And so, interestingly, you’re using a biodegradeable material and the mycelium. You’re using agriculture waste which is otherwise going into garbage; you’re able to use that in a practical manner.

And then the molds that you’re using, I assume obviously are reuseable. So you use them temporarily to form the brick, but you can still use that again after. Is that correct?

Dr. Mercedes Garcia Holguera:

Exactly. Yeah, those molds you can use them again and again.

Jen Hancock:

So, what was your thinking behind your research? What was your goal, ultimately, when you started looking at this kind of material?

Dr. Mercedes Garcia Holguera:

That goes back to the work that I was doing during my PhD. And it links to the ideas that are supported by biomimetic design and biomimicry. These two design approaches, what they propose is that we should look into nature and we should learn from nature, because there are all these many lessons, all these many wonderful solutions that nature has found to many questions that we are facing today.

One of the things that you can do when you start to look into nature is you identify what are the functions, the processes that some organisms or group of organisms are achieving or have perfected and how we can transfer that, in my case, into building design.

Jen Hancock:

Did you use your location at the University of Manitoba, also, looking at what was around you as part of the inspiration for going this direction with your research?

Dr. Mercedes Garcia Holguera:

I’ve been at the University of Manitoba for five years only. And at first when I arrived here, I knew a little bit. And even today, I only think that I know a little bit of the context of the province and the historical layers that are present here.

But once I understood that we were in a agricultural province, and that Manitoba has one of the largest indigenous communities in Canada, and also that many of these communities are living in remote areas and also in very cold areas, that’s where everything started to make more sense.

I mean, working with mycelium, which is very, very eager to (laughs a little)—to eat this agricultural and industrial waste made more sense because of the amount of agricultural waste that we can find in the province.

But also, when you think about the needs that some of the remote communities in the province—but also in Canada—have in terms of shipping costs of construction materials, it started to also make more sense to find a way of letting these communities to grow their own materials, to have a source of local production of construction materials that would reduce this big, I would say, issue or challenge that they have.

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Jen Hancock:

We’ll be back with Dr. Mercedes Garcia Holguera after this.

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Geoff Capelle:

Bird Construction’s century-long impact has been etched into the fabric of the Canadian communities that we’ve helped build from coast to coast to coast. From the social infrastructure that enriches our communities, the transportation and communications infrastructure that connects us, and the power, energy, and resources that move us, Bird builds with a collaborative culture and solution-focused mindset to build a better tomorrow. To join our team or learn more, visit Bird.ca.

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Jen Hancock:

Traditional clay bricks last as close to forever as we could want. But that’s not the case with mushroom bricks, and other biomaterials. At first glance that seems like a bad thing. But Dr. Garcia Holguera says that, actually, it means these materials could be really flexible, and useful in totally different ways to traditional building materials.

Dr. Mercedes Garcia Holguera:

And that is one of the things that, to me, it’s most interesting. Because it requires us—designers but also users—to change our perception of how we think about the permanence of buildings and built structures.

The fact that most biomaterials have shorter lifespans means that, not necessarily that they are weaker or that they are not as good, it’s simply that they have different characteristics.

And I think it’s very important that, for example, in my case at the university level, that we start to work with the students but also with professionals about what this means in terms of how we think about design. How we can start to imagine buildings that maybe have pieces, or elements, or parts that will have to degrade faster and that we’ll have to replace at a different pace.

And I think that is something that will help us to align better to natural cycles. And it can be something very interesting and very transformative. But that’s still, I would say (laughs a little), like very, very theoretical.

Jen Hancock:

Would you suggest, when we think about—we—we have to change the way we think about designing buildings, there would be parts of a building that would be designed for longer term, more permanent, and you would integrate a material like this, like what does that look like in the design phase where you might integrate materials that are designed to biodegrade faster and that you might have to replace? What does that look like more practically? Or what—what are you theoretically imagining that’s going to look like?

Dr. Mercedes Garcia Holguera:

Yeah. Like because we are talking about imagining (laughs a little), and right now I’m—I’m just imagining. Like okay, if we know that we are going to have an extremely hard winter, and we are estimating that we will need two additional inches of insulation to reduce the amount of energy that we need to use in our building, it would be great if we could grow, naturally, that extra two inches of insultation. And then when springtime comes, that naturally decays or we are able to remove it in an easy and natural way.

Jen Hancock:

You know, there’s houses that use straw as insulation. And straw also is biodegradeable, but when it’s locked in a wall it can last for a really long time. Is there a difference between this material—the mycelium material that you’re making? I assume that it would be faster biodegrading if it was more exposed to elements. Is there an application where it could actually be put in walls in insulation and doesn’t biodegrade? Or does it biodegrade at the same kind of pacing, then?

Dr. Mercedes Garcia Holguera:

No. I think what you are saying is completely correct. There are applications in which what we imagine is that the mycelium-insulating material will be sandwiched between two other rigid—it could like maybe plywood material or other more rigid materials that will both contain and protect the bio-based product, and also will reduce, as you are saying, the biodegradability—they will reduce the rate of degradation.

I think that’s what we will see, sooner (laughs a little) than what I am suggesting as a theoretical exploration where we accept the shorter lifespans of these materials.

So the things that you see again and again is that we try to mimic or to reproduce, or at least to equal, the properties that we find in traditional materials with these new biomaterials. We try to make them behave or perform in a similar way.

So there are these two, I would say, pathways: the pathway in which biomaterials or mycelium-based products try to compete with traditional materials, and they are doing that very well in the insulating forefront; or there is the other pathway when you design for the specific properties and the potential of these biomaterials.

Jen Hancock:

Right.

And that actually leads me into—you had mentioned earlier about remote communities. And so bringing in this idea of designing for specific materials. One of the benefits of the mycelium panels or bricks is that they’re grown. And it could have big implications for remote communities.

Can we talk a little bit about how the materials might be then sourced and how a community might be able to do that for themselves—giving them a bit more control over how they can fix and/or build buildings in their communities?

Dr. Mercedes Garcia Holguera:

Yes. We think that these communities would be able to set up small community-based biolabs where they could, for example, decide, “Okay. We’re going to do this project. We will need this amount of materials. And we are going to need this insulating materials. Let’s grow our own insulating panels in community. Let’s start to see what are the materials that are in our community that we could use, ah, as substrates for the mycelium.”

And ideally, you will harvest all those cellulose-rich waste products. Or even, like sometimes you have some industrial waste, leftover wood from other projects, or even wood from broken furniture, etc. that you could break into small pieces and turn into substrate for the mycelium.

So that basically bringing the right type of mycelium strain would be something that will come externally, maybe. Although there could be locally a—mycelium strains that are local to that community. And if the properties and the characteristics of those strains are appropriate, they could do everything within the community.

And that’s how we envision that small community-based biolabs could help in these communities to grow their own biomaterials.

Jen Hancock:

So in terms of scalability, what’s maybe unique about this is the challenge you’re experiencing right now is giving you some feedback to say that, you know, communities might be able to scale this and do it on a smaller scale. But I assume, also, then that you’re thinking you can mass produce the bricks, as well, in a more centralized location.

Dr. Mercedes Garcia Holguera:

Yeah. Like there are companies that are already mass producing, ah, mycelium-based products. A big one is in the States, and a couple in Europe. So this is not new science. What it’s new and what it’s important to us is how can we bring this to communities, and how can we make this way of working with biomaterials adaptable to specific regions, in our case, to Manitoba.

And how, for example, there are different mycelium strains. Some of them are very good or very resistant to contamination. Some others are tougher and they grow slowlier but they produce sturdiest and heaviest bricks. Others are very good for their insulating properties or how they arrange.

So there are all these different characteristics. And what we are trying to do is to make it as focused on the local, ah, needs of, first, Manitoba but also northern communities and isolated communities, and make sure that this fits within this idea of local production of biomaterials.

Jen Hancock:

I know that, obviously, this is still in experimental stages. But do you see this as being widely adopted down the road?

Dr. Mercedes Garcia Holguera:

Yeah. Like if you ask me specifically about mycelium-based products, I think that research right now it’s quite solid. It’s advancing at a good pace. And it’s already spreading in different areas—packing, insulating material, bricks, etc. So I think this is not going to stop, it’s going to consolidate.

And we are at that point where, hopefully, we will soon start seeing materials that are certified to be used in the construction industry.

And I think from there it will be more a specialization of each company that will specialize in a different type of product.

But there is also a need for companies to re-design or maybe to be created from scratch, because the production of biomaterials for construction it’s very different from the production of traditional construction materials.

So those are things that are very important challenges to address. But I am pretty optimistic.

Like when you see the amazing work that companies that are working with packaging and these smaller-scale products, it’s only a matter of when these companies decide to jump and go into the construction industry.

Jen Hancock:

If I can kind of ask you to just dream big, look to the future, what do you see when it comes to biomaterials in construction and architecture and engineering?

Dr. Mercedes Garcia Holguera:

What I think, and what I hope, is that—and I’m trying to be realistic. I’m not going to be dreaming like kind of a (laughing) as a like when I’m with my sci-fi books. But what I think will happen is that we will slowly but continuously we’ll see how traditional materials are being made in a different way. I don’t think that we are going to see a mushroom house anytime soon. But you might start seeing like, okay, this portion of the insulation of this house is using mycelium-based products.

But I don’t think that we will get rid of traditional construction materials. And we don’t want to. There are some elements of our buildings that are made to last, and we need them to last longer—for example, structural components. But there are other elements of our buildings that could benefit from a faster or shorter lifespan. And I think that’s where biomaterials can play a very important role.

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Jen Hancock:

That was Dr. Mercedes Garcia Holguera, assistant professor in the department of Architecture at the University of Manitoba.

Thanks for listening to Building Good. If you want to keep hearing conversations about the future of architecture, engineering, and construction, stay subscribed at any podcast app.

Building Good is a Vocal Fry Studios production, in partnership with Bird Construction and Chandos Construction. The producers are Jay Cockburn and Katie Jensen, with production assistance from Jessica Loughlin and Joanne Hignett. I’m Jen Hancock, thanks for listening.

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