Designing for Repair: An integrated design and repair framework for 3D printing in architecture

The architecture, engineering and construction industry (AEC) needs to pivot towards a circular design paradigm to mitigate environmental impacts by keeping buildings, components, and materials in circulation longer and reduce waste. A highly resource efficient method is retaining through repair. Repair is a complex and labour-intensive practice responsible for ensuring the functionality of the built environment. Designing for repair (DfR) is an emergent approach, however underexplored in architecture, where repair is normalized as a mundane activity sustaining the stability of the built environment. To enable DfR requires that design and manufacturing processes have a direct engagement with the constituents of the repair practice - the inspection, diagnostic investigation and decision-making, to address continual material transformation. Architectural design continues to focus on creation and is attached to an expectation of permanence and stability. Consequently, it evolves separately from the relational and dynamic networks in which buildings exist and where repair operates.
This thesis conceptualizes design for repair in architecture by developing an integrated design and repair framework using 3D printing technologies. To blur the clear-cut boundaries between repair and design necessitates introducing repair thinking in early design stages and recognising the creative potential in repair interventions. To do so, this project draws from interdisciplinary theoretical discourse where breakdown is foregrounded, repair is studied as relational and creative, while architectural design is positioned as open to change and anticipatory of repair.
The focus of this research is 3D printing with biopolymer composites. 3D printing, conventionally used as an endpoint for new production, is expanded in the context of repair and iteratively applied and adapted to ongoing material transformation. The material case study, biopolymer composites, is a hygroscopic material class which has an accelerated response to environmental conditions. Conventionally considered unfit for industry standards, this project leverages their shorter lifespan to enable the framework.
A hybridised research-through-design (RtD) methodology is employed to pursue this investigation. Methodological approaches from outdoor exposure testing and building pathology are used to extend RtD to investigate how experimental samples deteriorate. Knowledge is thus generated through iterative designing and repairing experimental samples. These are differentiated as this research progresses as probes, prototypes and demonstrator. They are subjected to cycles of design, diagnosis and repair, leading to a secondary mode of differentiation specific to each cycle phase, categorizing them as design, as deteriorated and as repaired. The research is thus matured from a design perspective, a material examination perspective and a repair practice perspective. This project is structured through three objectives specific to each cycle phase and advanced through four experiments initiated through research questions.
The thesis reports on methods of inspection, 3D scanning, diagnosis via computational analysis and repair through 3D printing. It investigates decisionmaking, weaving together activities performed on exposure sites with activities performed in the fabrication lab through both human and machine means. It develops a design language informed by material transformation over time and repair processes. This research culminates in the making of a demonstrator, the Repair Pavilion, which takes the research from the lab and into the everyday life, exploring an architecture where repair is central, where endurance is achieved through iterative fabrication rather than material durability.
This PhD thesis contributes to the growing research field on additive manufacturing in architecture. The main contribution is the development of the design for repair framework for 3D printing. It is enabled by continuity in tool deployment across multiple cycles, implementing repair thinking in design processes, exploring generative processes in repair, exchange of information between different cycle phases, and responding to material behaviour accumulated in time. Together, these technological and conceptual developments aim to challenge our current expectations of permanence and stability within the built environment and enable an architecture practice aligned with broader ecological networks and considerate of care activities.