Sustainable Construction: Additive Manufacturing in a Circular Design Framework

The current pressure on the Planetary Boundaries (Rockström et al., 2009) and the acknowledgement of architecture and the wider built environment’s impact here upon require a step-change in the way we conceive, design and build architecture. For architects and the further stakeholders in the built environment to truly participate in overarching climate mitigation strategies, we must find ways to make building net zero and nature positive. A central part of this action is to consider the materials by which we build and the processes by which they are produced; the resource they employ, the energy it necessitates and pollutants they derive. Additive manufacture and 3D construction printing has been developing since the mid 1990’s. During these 30 years the argument for additive methods as a way of optimising materials
and diminishing waste has been part of a larger address for sustainable building. In recent years, this argument has been further extended with a renewed focus on circularity and recycling of building materials. Industry and research alike are aware that for additive manufacture to retain its relevance and to advance its technologies it must develop circular principles based on a localisation of material resource, waste stream uptake and closed loop recycling.
This chapter examines how 3D construction printing can incorporate methods of circularity, how it can be used to upcycle waste stream materials into novel classes of building materials and how it brings new challenges to how circularity is conceived, performed and evaluated. The chapter develops two concepts of material versatility and material transformation as central axioms by which the processing and production of circular 3D construction printing can be assessed. The paper reviews methods of evaluating circular design in the building industry to ask how these methods map to the processes of 3D construction printing and asks how they can be extended to support the assessments of circularity in 3D construction printing.
The chapter presents two explorative case studies developed within CITA (Centre for IT and Architecture) examining circularity through 3D construction printing. The case studies examine 3D printing with upcycled waste stream-based glass and cellulose reinforced biopolymers as experimental methods of fabricating architectural elements from waste stream materials. The two case studies are strategically placed on either side of the circular design butterfly diagram, examining both finite materials excavated from the geosphere (glass and silicate) and renewable materials grown within the biosphere (collagen and cellulose). This makes it possible to compare across these resourcing paradigms and understand how material flows impact on fabrication, its material composition, processing and final performance.