Material Acts: Re-fusing

What follows is a conversation on the material act of Re-fusing with Laurens Bekemans (LB), Ben Loescher (BL), Meredith Miller (MM), and Virginia San Fratello (VSF), and the Material Acts (MA) team. Re-fusing highlights practices that work adjacent to systems of mass extraction, instead incorporating overlooked and reclaimed materials such as earth and plastic waste into processes of aggregating and fusing.

MA: We’ll begin the conversation with the observation that, in each of your practices, there’s often ingenuity and atypical approaches to sourcing material. The materials that you work with fall outside of conventional extractive and discarding cycles, or you’re actively seeking to intervene in extractive procedures. What are your material sources, what led you to these spaces, and what does the work of getting material entail?

LB: I’ll jump in! We work with earth. It’s like catch-as-catch-can, right? The material that we use to make adobe and compressed earth block is everywhere. It’s underneath our feet, but, at the same time, it can be surprisingly hard to get to for practical and regulatory reasons. So we’re often working around the edges, looking for opportunities—like when you’re driving down the road and there’s a sign that says “free dirt.”

We get a lot of our clay from an aggregate mine that mostly sells gravel to CalTrans for paving and freeway repairs. The clay is thirty feet of what they call “overburden,” which has no commodity value and happens to sit on top of something that’s deemed super useful. So we’re driving around, looking for heaps of things, calling numbers on signs, trying to make connections because there aren’t traditional supply chains for the materials that we use.

VSF: Sourcing local, inexpensive, and even free materials is really important to us as well. We work in the space of additive manufacturing, which tends to be really locked down by the companies that make the printing equipment and sell the proprietary materials that go into 3D printers. In the beginning, we were priced out. We were buying used equipment, buying the materials to put in the printers… thinking about the financial accessibility of materials for ourselves translated into thinking about accessibility for others. Of course, earth is ubiquitous and free and is, in many ways, a non-commodifiable material. How do we keep it that way and make it mass-consumable at the same time?

We also work with salt, which prints really well because it’s sticky and it costs 99.9 percent less than the proprietary white materials that you put in a 3D printer. And, being in the Bay Area, it comes from right here, so I don’t have to pay to ship it around the world—and that’s really important in terms of thinking about the economies of construction. We also use materials in the waste stream like sawdust from the Sierra Nevada mountains, which are close by, or Chardonnay grape skins from Sonoma and Napa. These are materials that are essentially free.

We’re also interested, especially with materials like earth or ash, in the historical and political conversations that can be had about material provenance. Any 3D printing with earth or ash or salt sits in a continuum, a larger and longer context of building with these materials. We’re interested in that narrative, too, and understanding where we sit in a legacy that is already thousands of years old.

LB: Brussels is trying to position itself within Europe as a pioneering city in terms of circular economy and circular construction. At the political level, the government is organizing and pushing legislation in such a way that incites architects to consider reuse, and alternative geo-sourced, bio-sourced materials. What’s interesting, in contrast to California, is that Brussels has a set of contractors and enterprises responsible for the demolition of the city, and they bring concrete from demolition sites to recycling centers where they crush the material. These companies also excavate, for example, for the extension of the metro line and metro stations. There’s a riverbed under the city that is composed of really rich clay and sand. We are connected to these companies so when we are in production for projects, we can get specific, local ingredients for compressed earth blocks, rammed-earth mixtures, and plasters.

We’ve managed in the past years to set up what in French is called a filière, a material culture around excavated earth. And now our next step is mainstreaming this, making this economically viable.

MM: Hmm. I’m realizing that our practice, Post Rock, is an outlier here, in that we’re not working with earth, but we’re working with waste plastic. I do want to go back to something that Ben said about earth being everywhere. I would say that, unfortunately, plastic is also everywhere and is arguably becoming a geologic material. In fact, I think our initial inspiration for Post Rock was the discovery of a new geological material called plastiglomerate, which are rocks that turn up on beaches and in marine environments that are formed as waste plastics fuse with sand and seashells and other garbage, but they have all of the qualities of hardness and durability that make them, by definition, rocks. If it’s hard enough to be a rock in the environment, perhaps this re-fused plastic is hard enough to be an architectural material that has value.

In terms of sourcing, we’ve recognized that here in Michigan we’re at a nexus of manufacturing. There’s a long history of many different kinds of extractive and industrial activities in Michigan and, particularly in Detroit, there’s the auto industry. We’ve learned that a lot of the plastics that are used in the auto industry have similar performance requirements we would need to get a plastic product certified for use as building material. So we’re thinking about our project as providing a second life for plastic waste that gets discarded in the manufacturing process of automobiles.

I wanted to follow up on another thing Ben said about regulations acting as a filter. Earth is abundant, but regulations apply a layer of information to that earth, like what can and can’t be used. I’m curious to hear more about that because there’s a parallel with plastics. Plastics is a huge category, but actually, there are so many different kinds of plastics that are specially engineered for very particular uses. We found this presents a lot of challenges for introducing circularity. So I’m curious to hear more about the limitations of circularity with earth.

BL: Well, I think there’s a cultural bias against things that are free—because if it doesn’t cost anything in our peculiar cultural system, that means it has no value, right? Of course, we know that’s not true. And then with earthen materials, the more that they can be graded or standardized or classified or whatever, all of a sudden they become products again, right? For example, clay may be free until it’s identified as bentonite or something like that and then it can enter supply chains as a commodity.

Curiously, in the work that we do, there are a million different ways to make an adobe brick or a compressed earth block, and this is really vexing for a lot of engineers and regulatory types. One soil can make a competent brick with 11 percent clay but with a different soil, you might need 30 percent clay. Some folks can’t wrap their minds around material variability, so the strategy that we’ve been taking is to standardize around performance rather than specific content or classification.

Defining materials by their performance characteristics allows us to adopt language that regulators and engineers are more comfortable with. I mean, the truth is that building regulations and standards production are very expensive—so for a material that doesn’t cost anything, that means in a country like the United States, there’s no public benefit research going into these things. You either have to adapt and co-opt the existing system or commodify the material, which as Virginia was suggesting, sort of like starts to make it less desirable as an actual material to use.

VSF: I’ll tell you all a story. We have a building called the Cabin of 3D-printed Curiosities, which is made out of some of the materials that we’ve developed over the years. And we were able to build this because the cities of Oakland, San Francisco, and Berkeley relaxed their building codes in response to the housing crisis. There are just not enough places for people to live. So now you can build up to 1,200 square feet on private property without a design review. We could build a tiny building made out of Chardonnay and 3D-printed sawdust and salt because we’re faced with this much larger crisis around housing, and that sort of opened the door for us and possibly others to do backyard experiments. We are getting ready to do a 3D-printed earthen structure in Southern California and we need that to be engineered and approved and to meet building codes. I think we will get into a situation where we are making adobe using local clays and soils and we’ll have to test them, you know, for their compressive strength to make sure that they do meet the standards required by the building code. And we’ve done that once before in Colorado. So, we’re facing this—but again, it’ll be a small experimental structure. I don’t know what happens when you want to build housing, for example, or public buildings. That scale seems like an almost insurmountable hurdle to overcome, to get policy to change to allow for this type of construction to happen.

LB: We’re doing a few public buildings and a university campus here in Brussels. One project is a hempcrete structure, and we couldn’t find a contractor who could manage to do it. In Belgium, when you’re using these newer materials, it’s often too expensive when calculated by contractors or too risky or uninsured, and so on. So we organized an open workshop to build the project with the public. Another example, for another project, we were working with a newly developed rammed earth using stone dust, but only two craftsmen knew how to do it, and the building was thousands of square meters large. We first had to cultivate and share knowledge with people.

We’ve learned that when you use locally sourced materials that are not off the shelf, your material is less of a product, it is more of a cultural network. We’re challenged to set up new protocols for building and—always—to share knowledge.

VSF: I want to return to your comment about insurance and risk—the United States is a very litigious country, and so considering risk is important. Do you want to take on the risk of an earthen building in an earthquake-prone context? Ben, maybe you can talk a little bit more about this, too, because you’re working in this space as well.

BL: It’s funny because, with adobe and compressed earth block, the engineering for seismic is not tricky. They’re conservative designs and ultimately, with an engineer who is familiar with these materials, it’s not hard to prove the math on them. Your bricks or masonry units have known qualities that just get plugged into a model with rules of thumb and it all works out. The barrier is often cultural—it’s like, “adobe— that sounds that sounds suspicious,” right? So we have to adopt technical language that sounds more neutral. Let’s call it “unfired clay masonry” because that’s benign, and you can imagine the same sort of thing, the same sort of approach being used for other materials as well, right? I started doing this in 2006 without success for a very long time because I started at the local level trying to use so-called alternative materials. After several failures—because building departments are set up to say no—and once I started participating in national standards development and international building code, I realized it’s substantially easier to just change the building code for the entire United States and have it trickle down to the jurisdiction in California we’re working in than it would be to get a single building permitted in Los Angeles County.

MM: Yeah, I was going to bring upscaling, too, because it sounds like everyone has mentioned thresholds at which the rules change, or at which there’s more scrutiny as to what you’re doing or whether the building can stand up—and that might be literally the scale of the building or it might be the typology or it might be the jurisdiction. For us, there was a split in our research several years ago. We were making more composite materials and making bigger and bigger things. We were making these hollow monolithic structures and made a column and our idea was that we’d make buildings out of this. But we realized that the scale of the problem that we’re trying to engage with is so large that rather than us making these one-off weird monolithic structures, maybe we need to develop a product that could be manufactured.

Scaling up could mean not necessarily an object that could absorb more waste plastic, but producing something that would play nice with more conventional building. So that’s why we’ve been working on rainscreen cladding. But we still set the bar maybe a little too high in that we’re working on having it certified for taller buildings… I won’t bore you with those details.

It’s similar to what you’re saying— we’ve scaled up and scaled down, at the same time, so that we might produce something that would actually get used in the world. We maintain dreams of doing our monolithic experiments, but right now we have a lot of support for scaling our research into a commercial product. In a way, it’s a different relationship to material production and design, and it’s been an interesting learning process for sure.

MA: It’s worth noting how a lot of the work of bringing new methods and materials into common use and practice is taking place in the peripheries of the field, and further that it’s rather administrative labor like regulatory testing, production scaling, building code writing.

MM: Yeah, I mean part of what led us to cladding as a possible application for our research is the way that IP works. Early on we developed a patent, but the patent was for the process of thermoforming waste plastic with aggregates—the configuration of the mold, the application of heating— because we couldn’t patent plastic. I bet it’s the same with earth, right? You can’t patent earth. It exists. But maybe you can patent novel processes.

From a university research point of view, IP gives us some validity in that we have something that could be marketable. For us, as designers, we’re also interested in the aesthetics of the materials and we want to control the flow of the plastic, the textures of the different aggregates that we add, etc., and so the idea of cladding made a lot of sense.

Cladding isn’t structural, but it does need to withstand wind and other forces. It needs a certain degree of durability. The main thing is fire. Initially, everyone raises their eyebrows because you’re basically putting petroleum on a building. But, you know, again, different plastics are engineered for certain uses and there are many plastics that have already solved this problem, so it goes back to sourcing and the question is: what forms of expertise do we need not only to engineer and understand how this will behave under fire but also to navigate the plastics industry to use the right plastics? A lot of the process right now is building up a network of consultants and advisors just so we can build the supply chain that we need.

LB: I continue to think about different kinds of scaling, and want to share that the hybridity of BC architects and studies and materials emerged over time. We did our first earth project almost twelve years ago but it was more recent, as our practice started to get public projects, that we hit an economic limit, meaning the materials we wanted to use became too expensive in our Belgian context. bc studies began as a way to organize workshops for teaching and learning because there was interest in the materials we were developing. We held a workshop where volunteers helped us make over twenty thousand compressed earth blocks for a building. bc materials was then started to further research on these earth materials—and it is now our product arm that offers Brussels-based and Bruges-based materials to other architects and contractors.

With this scaling, we now have to think about production scale and placing a price on these materials. If we want to have more impact, how can we make our product accesible to the family down the road? So we started to do research. In Belgium, there’s already a culture around masonry, and machines for compressing blocks are common. To lower the price of a block, you need to produce more—not like making a few blocks at a time using a hydraulic press as we would in a workshop. We would need to make millions.

We started looking at machines used by concrete factories that compress concrete blocks used for sidewalks and so on. We hacked these machines that already existed in our city to instead produce large quantities of compressed earth blocks, and simultaneously established a set of industrial agreements. We were able to rent the machines for one day a week, the factory would help us with sales, and we could offer earth-based products at half the price they would be otherwise.

BL: You know, listening to you and Meredith both, it seems like a path opened up because there’s an analog for the material, whether it’s a facade panel of which there are lots of types, or a masonry unit that’s culturally familiar: it provides a framework for people to understand what you’re up to. And I guess I want to ask Virginia: do you have an analog? It seems that a lot of the work you’ve been doing just breaks all the rules. It’s not just a bit of a misuse of a material, it’s an entirely new method of assembling and it’s like, oh, well, you just need to think of it.

VSF: There are lots of misconceptions, like people will just have no idea how you’re 3D printing. I feel if you look at a compressed earth block, you understand how it was made just by seeing it and if you look at a piece of, say, 3D-printed wood, you don’t. There’s a lot of mystery and confusion around the materials that we’ve experimented with over the years, and I guess we’ve tended to stay in that early phase of research, a space where we are inventing the materials at particle scale—we’re doing a lot of bench testing.

We are thinking about algorithmic code as well. How does the code and the toolpath make this material perform better? How does the geometry that I’m scripting improve the programmatic qualities or the structural qualities? And more recently, we’ve been working in the space of developing simple robotics. So we’re working with a fabricator who makes 3D printers to make a really lightweight robot arm. We haven’t gotten to the point yet where we’re considering policy or large-scale building or trying to meet ASTM (American Society for Testing and Materials) standards. It seems like a big hurdle to me to jump over and I’m torn. Do I just stay back here and let someone else take that on or is it a line that I really need to cross and is it time to do that?

MM: It seems tools are a way to address your question, Virginia: do you need to be the one to pass the standards? It sounds like the research and figuring out of which tools work with which material composites is a huge contribution that could be built upon, and it makes me curious what your attitude is about open source or proprietary knowledge. Do you see the development of tools as something that would be available to other people to build on your research, or do you see them as staying within your practice?

VSF: We published a book that has some of our recipes in it, so we’ve given away some material formulations, and we sell the software that we’ve developed for 3D printing with clay for a very, very low price. We’re not making a profit off of it, it just helps us to pay to host the software in the cloud. Ronald and I are of course both professors. We teach our students how to do all of the things that we have learned ourselves. If they go and work for another architect or designer and they take the workflows they’ve learned to another practice, that’s fine because we’ve taught them how to do it.

And we think a lot about tools. We’ve moved into the space of working with robotics, which sometimes means fabricating our own end effectors, you know, literally making our own tools. And so our thinking is beginning to shift toward making these tools open-source and placing them online for anyone to download and 3D print and put on the end of their robot arm. It all returns to a desire to lower the bar and to make things accessible in terms of material use. We have the same ethos and philosophy with materials as we do with software and tools and shared knowledge.

MM: Yeah, yeah, I think that’s so important.

MA: We keep thinking back to what Laurens said earlier, about material as a network. Sharing thoughts on access to information, production of tools, forums of collaboration, and various kinds of knowledge that get pulled into these efforts—this is a great culmination of our conversation. It is, in a way, an expanding of a network; we can all see ourselves as extensions of and resources for each other. We want to offer this reflection in closing, but also ask if any of you have final thoughts or a better way of wrapping this up.

LB: We’re all quite hybrid as practices, and I feel there’s a human understanding of all the challenges met when you’re not following a blueprint. When you’re trying to find your way, you have to do things differently and spend energy in a very different way. I appreciate this culture around materials, and I really do connect to thinking about materials not as products but as networks. We are building a regional material, it’s not like a concrete product that might have been produced on the other side of the world. The material relates to your human network or your geographical network.

BL: Yes, the network aspect is really unique to these emerging and non-traditional materials because once something is normal and commodified, it just sort of disappears into the landscape of economic interactions and, also, into industrial secrecy. At the risk of sounding like a Marxist or something, there is some unquantifiable benefit to entering a dependency that’s noneconomic with with other individuals, and these materials enable that.

VSF: I’ll just go with what they said and also say, to be continued. It’s all this ongoing work we’re talking about, and it’s hard to summarize because you are right in the middle of the work, it's progress in process!