Lessons Learned of Project Milestone (2023-06)¶

Project Milestone consists of a series of five 3D printed residential houses in the Netherlands, of which the first was opened in 2021 and is currently inhabited. The structural principle is based on 3D printed load-bearing concrete wall elements, which are curved in- and out-of-plane. This demonstrates the freedom in design enabled by printing, and simultaneously provides structural stability both during manufacturing and in the final use phase. In this contribution, the results of 3D printing experiments and structural tests are presented, which provided the basis for the structural analysis and building permit of the printed house. Two wall types are considered: one consisting of relatively straight elements with a printed inner- and outer-leaf, with insulation in between, and one strongly inclined wall with a double layer and infill pattern. Both wall types have been printed successfully and were subsequently structurally tested in two configurations: centric and eccentric in-plane loading. The results of the printing experiments and structural tests were satisfactory and resulted in the successful production and assembly of the first house of Milestone. The lessons learned during the testing phase, as well as the final production and assembly phase are discussed. These are the starting point for improvements of the next houses of project Milestone, which are currently in their design and testing phase.