A Global Snapshot of 3D-Printed Buildings: Uncovering Robotic-Oriented Fabrication Strategies

This paper aims to provide a global snapshot of concrete 3D-printed buildings and to uncover robotic-oriented large-scale fabrication strategies. Therefore, an extensive internet search and literature review was carried out to investigate 3D-printed buildings. In this study, 154 construction projects with 204 buildings were systematically recorded and evaluated from 2013 up to 2023. Using an exploratory mixed-methods approach and a comparative case study analysis, a total of 88 3D-printed buildings were first evaluated descriptively. Thereafter, different existing printing strategies for in situ, on-site, and off-site production were identified, using an iterative approach. In addition to the geographical distribution, the descriptive evaluation also showed the key players as drivers for the spread of the 3D-printing technology and the correlations between printer type, fabrication strategy, and the building size. With regard to the printing strategy, three different approaches for in situ and off-site fabrication can be defined, depending on the printer types and their characteristics (work size and mobility): print-in-one-go, horizontal or vertical segmentation, and the multi-element vs. full-scaled wall strategy. However, the study showed that the data quality was sometimes difficult due to a lack of information and essential details of the printing process and segmentation.