Sustainability assessment and development of guidelines for digital fabrication in construction

In the era of technological innovation and digital revolution, inadequate working conditions and high resource consumption are still common practice in the construction sector, a sector that requires a deep transformation to keep up with other industries in terms of environmental impacts and productivity. As a potential solution, the adoption of Industry 4.0 technologies such as Additive Manufacturing (AM) in construction, promise to enhance the sustainability of the sector, resulting from improved productivity, efficiency, safety, collaboration, etc. In particular, the combination of computer-aided design and automated fabrication techniques for additive construction demonstrates the ability to produce complex architecture with optimized geometries and integrated multifunctionality. However, the contribution of digital fabrication processes to the improvement of sustainability in construction is not well covered by current research. The aim of this doctoral thesis is to identify the sustainability risks and opportunities associated with the implementation of digital fabrication in construction. Given this objective, the research focuses on the assessment of building elements constructed with additive digital fabrication techniques to identify under which conditions digital fabrication provides a sustainability advantage or disadvantage over conventional construction. The main assessment method applied is the Life Cycle Assessment (LCA) framework to characterize environmental impacts. Furthermore, the CYCLONE (CYClicOperations NEtwork) simulation model is employed to evaluate the productivity (i.e. costs and time). The analyses indicate that the relative sustainability of the evaluated projects depends primarily on the manufacturing of building materials and the impact of digital fabrication processes is negligible. Moreover, the results demonstrate that digital fabrication becomes a feasible construction technique for non-standard building elements. Specifically, the study highlights the opportunities of structural optimization and multifunctionality in complex structural elements to reduce environmental and economic impacts. The goal of the case study evaluations is to identify the design parameters that influence the sustainable performance of digitally fabricated architecture. Based on the identified parameters, sustainable criteria to guide the design of digitally fabricated building elements are formulated. These guidelines aim to provide designers the basic knowledge to implement the design strategies that are successful to improve the sustainability of digitally fabricated architecture. Finally, a LCA-based method is developed to consider sustainable criteria during the design of digitally fabricated architecture. Specifically, the simplified method is integrated in parametric design software to support decision-making from early design stages. The results provide the embodied impact of the digitally fabricated building element compared to a benchmark set by conventional construction. Based on the comparison, a color-based visualization allows non-LCA experts to efficiently optimize the design based on sustainable criteria. Finally, future research paths regarding the socio-economic implications associated with the implementation of digital fabrication in the construction sector are discussed. As the level of digitalization in construction projects increases, the concern about the future of jobs will rise. While digital fabrication has the potential to improve productivity in the building industry, it will not necessarily reduce employment in the long run. It is expected that existing roles will evolve, mainly related to the human-robot interaction, and new roles requiring digital skills will be created. Moreover, the digitalization suggests an evolution of the conventional construction organization towards a platform-based integration of planning and construction phases.