Professor in Residence, Department of Architecture, GSD, Harvard University, Cambridge MA, USA
Conventional building uses material as a fungible commodity. This debased understanding of materiality leads to environmental, social, and economic harm. The research program described here valorizes material as a common good: an asset shared by industry and community stakeholders to foster sustainable physical environments. A series of consolidated practices explore biochar as a building material feedstock. Biochar describes a range of byproducts from pyrolyzed (high-temperature, low-oxygen roasted) feedstocks like wood chips, sewage sludge, and farm waste. Biochar itself is a fine, lightweight, jet-black, and highly porous powder. Contrary to its carbon neutral use as a soil amendment, biochar holds carbon-negative promise in construction by removing airborne carbon from the carbon exchange cycle. By repurposing biomass waste biochar offers a corrective to extracting resources for building materials. Using a materially driven design approach the research program explored biochar as a fine aggregate, or sand, replacement in concrete specifically for precast concrete architectural panels. Sand mining, transportation, and scarcity have deleterious environmental impacts, and the replacement of sand with biochar results in a range of diverse thermal, hygroscopic, and mechanical properties.