Respyre

Auke Bleij

Respyre is developing moss concrete: an innovative building material where living mosses grow on concrete facades. Moss is not only beautiful and low maintenance, but it also purifies the air, cools the environment, and gives small insects a place to live[2]. By cleverly using existing manufacturing processes, this innovation can compete with traditional facade finishes.

Urban areas can be 1 to 12 °C warmer than their surrounding rural areas. One of the main causes is the use of materials like asphalt, steel, and glass in buildings. These materials absorb more sunlight and retain more heat than green areas. Vehicles, air conditioning, and industry also cause waste heat. And as cities continue to expand, green spaces and their associated biodiversity are diminishing, further reducing evaporation and shading.

We speak with Auke Bleij, founder of Respyre – about his fascination for nature-inclusive building, mosses as microscopic forests, and the importance of entrepreneurial minds.

Text: Lonneke Craemers
Photography: Blickfänger

Hi Auke, congratulations on your spot at the Secrid Talent Podium! Let’s start at the beginning. Were you an entrepreneurial child?

I lived in a small village on the outskirts of Amsterdam. I was always pretty good at school and incredibly competitive. I remember being in second grade. One of my best friends was a better reader than I was. I rectified that in three weeks. I simply had to be faster.

My father ran his own business, so I had that as an example. I was always organizing little markets or doing odd jobs around the neighborhood. I learned that you could see an idea grow into something real.

As a boy, I was often critical of my parents. I enjoyed challenging them. When they got divorced, for example, there were times when we had less money. When we went out to eat, I’d suggest we could just cook at home instead. That’s still in me. I often find myself wondering why things are the way they are.

What are things that make you ask why?

I can be especially cynical and dissatisfied with how we treat our world. But aside from being cynical, my group of friends sometimes also tells me I’m manically positive. I always think that everything is fixable. I tend to quickly dismiss all the excuses for why something can’t be done. Sometimes too quickly, I must admit… But I genuinely believe we can improve in a lot of areas.

For example, something that really bothers me is when stores have their doors wide open on a hot summer day while a large fan cools the store. These fans guzzle energy, water, and money, and they blow even more hot air into the streets. I find this so contradictory.

Amsterdam Zuidas is another example. While I can certainly appreciate the architecture there, there also seems to be competition as to who can create the biggest glass facade. But when these facades are in the sun, they heat up, which means more air conditioning. Glass also reflects a lot of solar radiation, heating up the surroundings. We all pay the price for that.

The only reason for glass facades is to boost brand and property values. They may look nice to some. They’re luxurious, but none of that outside building space is being used in a positive way.

Did you study at the TU Delft to innovate the world of construction?

Initially, I enrolled there because I was good at math. TU Delft was well regarded, so honestly, there was also a sense of pride involved. But when I went to graduate school, a moral component entered the mix. I believe that at some point we really need to stop building houses for us humans alone. Why do we not create objects that also serve nature and support biodiversity?

For example, I visited the Faroe Islands. Looking at the natural rocks there, you see nature woven into the landscape. There are places where birds can nest, and plants can grow from seams. I think it would be cool if we could encourage that kind of interaction with our buildings instead of sterile construction, incorporating anti-biological pesticides into our facades to keep them white and shiny.

We’re in the middle of a climate crisis, and we have all kinds of problems in the city, such as particulate matter, noise pollution, heat management, and water retention. We currently spend a lot of energy controlling symptoms and regulating everything mechanically by adding all kinds of things. In Bangkok, for example, they are already using mist systems to keep the streets cool. But I believe we can self-regulate all those functions in a city by seeking out interactions with nature.

It’s really time to start building in a nature-inclusive way.

You want to build in a more nature-inclusive manner. How did you arrive at moss concrete?

My graduation thesis was about cooling the city, which arose from my feelings of irritation with open store doors. I theorized that we needed to be able to store moisture in facades. After a long detour, I met Mark de Kruif. Together with two professors, he had come up with a practical solution: concrete covered in moss.

Mark is a technical physicist. He didn’t know much about concrete and was looking for someone to help him with that. I had just finished my degree in civil engineering and, as an entrepreneurial spirit, felt strongly drawn toward a startup, so we started. Mark has since moved on to other things, and my associate Adil, who has more experience as an entrepreneur and a background in chemistry, has joined.

Can you explain what moss concrete is?

Moss concrete is a living facade finish. As the name suggests, it’s a combination of concrete and mosses. Together, they form an exceptionally robust building material that lasts for years. There is a concrete-like facade that preserves your building’s functionality, the inside is wind- and watertight, but the outside is intentionally bioactive and seeks to interact with mosses.

If you go outside now, you’ll see mosses growing on their own on stony substrates. We mimic that process with moss concrete. It’s like creating a garden: you start with good soil, then you plant the right seeds, which you subsequently water during their growing period. That’s how it works for us too.

That “soil” is the concrete. We use an incredibly open, porous concrete layer on the outside of a building. This layer, which is 87% circular, is made from Amsterdam’s demolition debris, and the cement we use has a relatively low footprint. We then apply moss coating to that concrete. These are the “seeds.” They contain four to six species of moss, which we know like to grow at a specific orientation.

What are the ecological benefits compared to an ordinary facade?

Mosses are able to retain moisture, which evaporates when exposed to sunlight. This contributes to natural air cooling, especially in cities. There are also advantages in terms of urban air quality and biodiversity.

Mosses are actually microscopic forests. When you zoom in on them, you can see trees with pathways. It’s really like walking through a tiny forest. A lot of air, which contains particulate matter and carbon dioxide, flows through them. These are physically retained on the surface or absorbed into the moss tissue due to the structure of the moss. Some mosses can even filter heavy metals or nitrogen from the air.

And then there is biodiversity. Small insect life in the city benefits from mosses. This micro-biodiversity forms an important link between bees and birds. When a bird is unable to find a worm, the whole ecosystem breaks down. We’re still mapping and actively measuring a lot of those ecosystem services in collaboration with Naturalis and as part of a PhD called “Hidden Biodiversity.”

What does your production process look like? Do you make everything yourself?

There are two options: prefabrication and renovation. For prefabrication, we work with concrete manufacturers, among others, who just want to meet their production rates. We’re a supplier to those manufacturers, giving them an opportunity to expand their product portfolio with a green product.

We have a concrete recipe, and they have silos with different materials in them. Our concrete is in one of those silos. Whether those concrete manufacturers grab a shovel from silos 59 or 83 doesn’t matter much to them. They can easily produce custom panels using our recipe whenever a customer requests it.

We do produce our own recipe – our moss coating – ourselves. This recipe consists of two components: the mosses and the ingredients used for the coating. We rented a 1,500-square-meter nursery in Nieuwveen early last year, where we grow the mosses we need. We harvest them with a kind of kebab shaver, lay them out to dry, and grind them into a powder.

As such, the granulate for our bioreceptive moss concrete is made entirely from concrete waste, which we receive from Rutte Groep in Zaandam. Our coating is sprayed onto a facade like paint. It’s easy to apply, so we prefer to outsource the application process to construction companies or other parties. We want our solution to be both scalable and for the people using it to give honest feedback on how it works.

Mosses are actually microscopic forests.

Do you need to continue to take good care of those mosses after they’ve been applied?

Moss has one huge advantage: it is low maintenance. It doesn’t have roots, but rhizoids, which attach like velcro and are non-invasive. Thanks to a drought-resistant mechanism, some species can go months without water. Put simply, they are plants you don’t have to look after once they’re growing.

During its growth phase, however, the moss does need to be irrigated. This is why we install a pipe system at the top of the facade that allows water to flow over the wall. In this way, we can create a complete layer of moss in 10 to 12 weeks.

In all honesty, I have some resistance against this irrigation process, but without it, we cannot presently meet our clients’ commercial and aesthetic demands. Unfortunately, the amount of water that naturally falls on a vertical surface is quite disappointing. This is especially true if the building has a roof edge, which applies to 99% of the buildings in the Netherlands.

What kind of projects have you already completed?

We have quite a few projects underway. This growing season, six new projects will be added to our portfolio, including one in Abu Dhabi. We renovated a large residential flat in Purmerend, a packaging center in Eindhoven, and a commercial office building in Haarlem, where we combine insulation with our material. In Kortrijk, we worked on a large warehouse that is already green.

We’re using these pilot projects to work through initial growing pains. In Kortrijk, for example, we needed to intervene. In some places, we couldn’t quite get the moisture under control, which gave other organisms a chance to grow. We had to scrape away part of this growth with a high-pressure sprayer and recoat it.

There is no project yet that has been in place for a few years and which is perfect. But these are life-changing projects that are very important to us. It’s incredibly valuable to work with clients who understand that.

What are the costs of this method compared to traditional or alternative facade materials?

We want the benefits of green for the price of gray. We’re never going to compete with the cheapest version of gray, but compared to glass, we’re three times cheaper. I consider glass a form of gray, because it does nothing for the environment and is purely aesthetic.

In terms of cost, we lose out to masonry and precast concrete. These materials have huge volume outputs, but they don’t do much for the ecology either. We easily beat all the other green alternatives and highly aesthetic facade finishes, such as stone strips and certain types of plaster.

How important are aesthetics to you?

Besides contract awarding, aesthetics is the biggest reason customers buy our solution. Our clients are property developers or contractors. Architects are our advocates. They expect a beautiful, homogeneous, green wall that is alive and just looks great. And I think that, as an architect, you should be proud of your work.

What works in our favor is that “land incorporation” has become a buzzword among municipalities. In other words, not building a gray box in a meadow. And rightly so. Nature is much more beautiful. Besides, natural forms and natural behavior are very good for our well-being. They have a positive effect on our brain.

A lot of people take pictures and videos when they see our project, which I also consider to be a role of aesthetics. That overwhelming online enthusiasm has been ongoing for years. People like what they see, and of course that helps us. It makes a difference when a project manager at BAM, for example, sees not one, but ten videos of us going viral. We’ve already been approached by all the major Dutch players, without having much money or time for communication ourselves.

The benefits of green for the price of gray.

What could you use help with for the next steps?

We’re still in a semi-technical development phase. We need clients who can be flexible and who feel energized by that. We’re looking for partners who want to join us for the ride.

It’s crucial for us to focus on what is coming in and what goes out. The amount of requests that we’re actually able to move forward on and the percentage of successful deliveries is not yet consistent enough. There’s still too much fluctuation. We want to get out of that so we can start doubling our operational clout.

How do you envision the future?

On the one hand, I think it would be cool to roll this out very quickly in cities where the issues are more pressing than in the Netherlands. In cities like Chiang Mai or Mumbai, for example, cooling and tackling air pollution are much more relevant themes. This is why we want to set things up in such a way that we can quickly replicate our process in other countries. Think of a franchise concept, for example.

On the other hand, I recognize that moss concrete is not the perfect solution in all situations. We want to return nature to the city and that involves more than just moss concrete. A second storyline, therefore, is that we’re coming up with several new nature-inclusive, scalable concepts. Consider a concept related to flowering that benefits bees, for example. Moss isn’t the remedy. It’s part of the bigger picture.

Finally, what message would you most like to share with people?

I want them to feel excited. I hope my story inspires people to also start doing something that brings positivity and serves other people and nature. Especially in these times, in which war seems to dominate.

But people should also be aware that it’s extremely hard work. Sometimes, I get the feeling that all this enthusiasm on Instagram makes people think that things are only good and easy. I don’t want a discrepancy to arise there. Our team of four is working extremely hard to make sure this is going to work on a large scale.

We need people with clout, who like this story, who understand us, and who want to help. We have a lot of space for that. And if not for us, there are so many other problems in the world that you can do something about with an entrepreneurial spirit. We’re doing that now for nature-inclusive building, but there are so many other really cool ideas.

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Respyre

Auke Bleij

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