This research-driven summer school was conducted as a joint workshop between Columbia University GSAPP and ETH Zurich’s Digital Building Technologies group. Bringing together students from both institutions, the program investigates the architectural potential of a novel foam material made from recycled fly ash developed at ETH Zurich’s Complex Materials group. The summer school frames material reuse and circularity as design drivers, examining how industrial byproducts can be transformed into performative building materials at an architectural scale.

The workshop focuses on hands-on experimentation with the material in both its liquid and hardened states. Students investigate how fly ash foam interacts with different formwork systems and assess its structural, thermal, and acoustic properties through large-scale casting experiments. Questions of span, load-bearing capacity, drying behavior, and surface articulation are explored through systematic testing, positioning material research as an integral part of the architectural design process.

Several digital fabrication strategies are explored in parallel. These include robotic 3DP of concrete without conventional formwork combined with foam infill, 3D-printed perforated stay-in-place formwork that becomes part of the final architectural assembly, CNC-milled folded formwork using lightweight recyclable sheet materials, and hybrid workflows combining large-scale UV 3D printing with vacuum-formed molds. Each technique exposes students to the constraints and opportunities of advanced fabrication technologies while encouraging comparison across systems.

The summer school emphasizes interdisciplinary collaboration as a core pedagogical objective. Guided by faculty from Columbia GSAPP, ETH Zurich DBT, and industry partners, students work across material science, computation, structural testing, and digital fabrication. The resulting full-scale prototypes demonstrate how experimental materials and digitally fabricated formwork can expand architectural design space while remaining grounded in performance, constructability, and environmental responsibility.