Extending the Circular Design Framework for Bio-Based Materials: Reconsidering Cascading and Agency Through the Case of Biopolymer Composites

Pressing issues of sustainability drive the pursuit of new circular bio-based design frameworks in order to limit the use of finite resources and fossil fuel energy consumption. In architecture and the built environment these efforts have fostered a renewed interest in bio-based materials as the only truly sustainable resource for building materials. However, bio-based materials are different to the resources that cascade through technological cycles. With the increased interest and application of bio-based material in the building sectors comes the realisation that they do not map directly on to existing models of circular design for the built environment. In this paper we present an effort to extend the circular design framework for biopolymer composites in architectural applications. The paper takes point of departure in a mapping of existing strategies for cascading in the built environment. By presenting two biopolymer composites as case studies, we examine how introducing this class of materials into the circular design framework challenges the actions and implication of cascading and reconfigures the weighting of agency and control. The conceptual, technical and practical implications of the usage of such materials in future building practice are speculated on through the creation of six design scenarios that expand the role of cascading creating a new connectivity between material practices.