By the early 1900s, Pittsburgh, Pennsylvania, had emerged as an industrial powerhouse, due in large part to its prodigious steel production. More than a century later, the city has refashioned itself as a center for innovation. It is thus fitting that Jeremy Ficca, MArch II ’00, an associate professor and incoming Associate Head of Design Fundamentals in the School of Architecture at Carnegie Mellon University (CMU), has concentrated his research on biogenic building materials. Made from rapidly renewable resources such as plants and fungi, biogenic materials offer a sustainable alternative to standard materials such as steel and concrete, requiring less energy for sourcing and construction, and even assisting with carbon sequestration. This semester, as a design critic in the Department of Architecture at the Harvard Graduate School of Design (GSD), Ficca is teaching an option studio called “Material Embodiment: Logics for Post-Carbon Architectures” in which biogenic materials—and geogenic materials, which are sourced from the earth’s crust—feature prominently.
With respect to buildings, Ficca explains, we tend to think about energy and carbon in two ways. The first and more conventional outlook involves increasing energy efficiency for elements like heating, cooling, and lighting, often through technological means. The second relates to how and with what materials buildings are constructed, along with the externalities that accompany these design decisions, such as their impacts on human labor and greenhouse gas emissions. This more holistic approach underlies the “Material Embodiment” studio, in which students explore bio- and geogenic materials (such as hemp, straw, and earth) to design a hybrid workforce-training and research facility on an old river-front industrial site in Pittsburgh’s Hazelwood Green. The studio asks the students to rethink the material composition of a building as well as their designs’ broader implications on material sourcing, labor, construction technology, and maintenance.
Ficca recently spoke with Krista Sykes about bio- and geogenic materials, his own research, and the urgency for change within the architectural discipline.
How did you become interested in biogenic materials?
My teaching and design research focus on the intersections of materiality, technology, and architecture. While this initially operated within the field of computational methods of design and fabrication, material affordances were a common thread. As one who teaches courses and studios that focus on the materialization of architectural intent, I contend with the impact of building on our planet’s ecosystems through the carbon intensive and extractive nature of construction. Like many of us, I spent time during the pandemic looking inward. The writings of ecological economist Tim Jackson were an important influence on my understanding of post-growth and the imperative to transition to a more resilient economy and society. Around the same time, I was asked to reconceive a core material and construction course for graduate students in CMU’s Master of Architecture program. Doing so provided an opportunity to fundamentally rethink this content in relation to climate change and resilience. The questions that began to arise through the development of the course and subsequent discussions with students highlighted the inadequacy of simply trying to achieve greater and greater efficiency in building performance rather than exploring how the building’s material makeup can substantially reduce energy and carbon expenditures.
We are at a precarious moment. There is broad consensus that our climate crisis requires fundamental recalibration of the acts of building to address the negative externalities of the process. There is no single solution to this immense challenge. Responses will be quite different depending upon local circumstances. I am interested in how material practices can address questions of embodied carbon and energy and how these practices might open space for design imagination and architectural expression. This is a technical problem but also a deeply cultural question.
In the North American context, the most universal biogenic construction material is wood. But there is a remarkably rich range of harvested and grown materials alongside wood, including bio-resins, mycelium, and hemp, to mention but a few. Some biogenic materials belong to longstanding traditions of building, while others emerged through rigorous research and development processes. My current work focuses on industrial hemp and lime, often referred to as hempcrete. While the combination of these materials to construct walls dates back more than thirty years, it is somewhat analogous with straw and cob techniques that have much longer histories.
You mentioned that some of the biogenic materials being explored in the studio connect to longstanding building traditions. Could you say more about the materials you have in mind?
Some of the students this semester are exploring loam (earth and clay) construction. These are practices with long histories that were largely passed over because they were incompatible with industrialized building techniques. There is remarkable work underway by architects like Roger Boltshauser and Martin Rauch that seek to situate these methods within the technological circumstances of our time. This is in part a process of reconnecting with practices that were perhaps deemed to be pre-modern, inefficient, or even primitive. But this renewed interest does not result from nostalgia or a desire to return to pre-modern vernacular techniques. Rauch’s development of prefabricated insulated rammed earth blocks is a response to the challenges of scale, labor, and construction costs. As their work is demonstrating, adoption of these techniques will require automation to address their labor intensiveness. Additionally, there is research underway at the Gramazio Kohler ETH research group developing robotic deposition of clay to yield monolithic architectural elements. It is a fascinating melding of high and low tech, of high precision and lower-resolution architecture. I find these calibrations, frictions, and occasional contradictions to be both exciting and a source of opportunity, prompting questions about the cultural connections between how we conceive of our environments and the materials with which we build.
How did your research come to focus on hemp and lime?
In December 2018 the United States passed the 2018 Farm Bill, removing hemp with extremely low concentration of THC from the definition of marijuana in the Controlled Substances Act. Passage of the bill legalized the growth and processing of industrial hemp nationwide. As I researched industrial hemp, I was impressed by its remarkable attributes as a crop and its performance as a building material. Per acre, industrial hemp is one of the most effective CO2 to biomass crops.
The convergence of the farm bill and the performance capacity of hempcrete that was emerging through research in the EU pointed to opportunities for applications in the US. There is a track record of industrial hemp farming in the EU and UK with a few noteworthy examples of buildings that utilize the material. I was initially drawn to the labor-intensive nature of using hempcrete as a site-rammed material, and its potential to inform incremental, process-oriented approaches to construction within domestic architecture. I was interested in how a house might grow over time along with the harvesting and processing of material. This work, at the scale of the house, has transitioned into the design of discretized assemblies.
How does your work dovetail with the students’ pursuits throughout the semester?
The studio directs attention to one of the fundamental elements of architecture—the wall. We do so in part because many bio- and geogenic materials lend themselves to solid construction that relies upon accretion, processes of layering, compressing, and stacking. Materials like hempcrete and rammed earth require solidity and thickness to achieve thermal performance. But we also take on the topic of the architectural boundary because it reveals contemporary tendencies and desire. Principal among them is the legacy of modernism’s focus on lightness and thinness. The students are exploring spatial organizations and expressions that are informed and inspired by materials that require different processes of formation.
The students are developing proposals for a skilled workforce-training center located on a post-industrial site in Pittsburgh that was once a coke works and steel mill. It is a site with a long and complicated history of industrial growth, human labor, economic and environmental collapse, and regeneration. As I alluded to earlier, some of these materials are quite labor intensive. There are different attitudes to this topic. Some argue for greater human energy over embodied material energy and embrace the potential for the creation of new skills and jobs, while others point to automation to achieve scale and affordability. I am not advocating for one approach; rather, I’m interested in how the students’ positions on labor and technology inform their work. How might they calibrate architecture to production by humans and machines?
Very early in the semester we cast some hempcrete blocks. This experience allowed us to work directly with the material, understand the limits of its resolution, and appreciate the characteristics of a low-processed natural material. Hempcrete, like many bio- and geogenic materials, can be hard to control. It is inherently somewhat imprecise. This pushes back against the characteristics of most contemporary building materials, which tend to rely on high degrees of precision and predictability.
Another point of convergence between my research and the work undertaken in the studio this semester is the topic of durability. Most buildings are constructed to be highly durable, to withstand weather and time. And there are many good reasons for this; buildings are expensive to construct and maintain. Some of the materials we have been working with challenge that approach in that they can be understood as weak, or to require different forms of maintenance and repair. A lot of the ways in which one engages contemporary construction is to try to minimize those conditions in a building. Over the history of many cultures, there have been remarkable practices of maintenance and care, some that also have functioned as cultural acts in society. So, when we build with materials that are low in energy, low in carbon, as great as they might sound, there are certain tradeoffs, and perhaps one of the tradeoffs is the fact that they might require different forms of care and maintenance. Rather than this being perceived as a problem to be overcome, might there be an opportunity here? Might this challenge the way we think about a building’s lifespan and open new ways of considering the traces of time and the finishing of a building?
As low energy, low carbon, sustainable alternatives to conventional materials, bio- and geogenic materials offer exciting possibilities. It seems that reframing potential problems associated with these materials as disciplinary opportunities renders them even more promising.
I agree. I want to be careful not to oversimplify or generalize. Making even a small building is a complex endeavor that relies on hundreds of materials with a wide range of embodied carbon and energy. These questions need to be considered holistically to weigh tradeoffs. The material practices we’ve discussed raise fundamental questions about the status quo of construction and its impact on environmental degradation; in doing so they open space for imagination. I find this territory, coupled with the various frictions and complications, to be quite useful for students to operate within.
*All images by Jeremy Ficca, unless otherwise noted.