Life cycle assessment of building envelopes manufactured through different 3D printing technologies

The advent of 3D printing technology in the construction field, as for many other industries, represents a technological upgrade. It introduces a paradigm shift in the way we approach construction and architecture, opening up new horizons and unprecedented possibilities. Indeed, due to its ability for infill optimization and reduction in material consumption, additive manufacturing (AM) can represent a sustainable solution for high-performance construction. While there is a growing body of literature on 3D concrete printing (3DCP), several aspects related to sustainability remain unexplored. Systematic studies assessing the sustainability of various 3D printing technologies and techniques to achieve a building envelope are missing in related literature. The present study fills a crucial gap in the literature by focusing on the environmental impacts and thermal properties of building envelopes achieved using three distinct emerging AM technologies and techniques. These technologies include large gantry cranes, small gantry cranes based 3D concrete printers, and Fused Deposition Modelling (FDM), applied in monolithic construction, prefabrication, and 3D-printed thin formwork for cast concrete components. The novelty of the proposed research is twofold. Firstly, it explores how different technologies and techniques can achieve target thermal performances for building envelopes through parametric modelling and thermal simulations. Secondly, it conducts a Life Cycle Assessment (LCA) analysis to identify the advantages of various 3D printing technologies and techniques in the context of building envelopes. The results showed that the investigated 3D printing technologies have low energy consumption and can represent a sustainable alternative to traditional structures. The impacts of different technologies can vary significantly depending on the configuration and internal infill; this is mainly due to the quantity of concrete used, which can account for up to 95 % of the total impacts. Hence, the sustainability of envelopes can be improved using configurations with thinner wall thickness (i.e., obtained with prefabrication or FDM-based formwork technique). By providing a better understanding of the sustainability aspects of these technologies, the study provides valuable insights for future developments in the field, guiding the construction industry towards more sustainable and innovative practices