Embodied carbon and energy of offsite 3D-Printed concrete walls

Construction 3D printing (C3DP) has emerged as a potential solution to the urgent need for housing around the world due to its promised advances in productivity. Similarly, offsite construction has gained traction for its ability to condense housing construction timelines and budgets. Combining these approaches could accomplish these improvements in tandem; however, the following case study shows that 3D-printed concrete walls have 54-99% higher embodied carbon and 33-45% higher embodied energy in comparison to the evaluated conventional methods (except for concrete block/brick exterior), largely due to material quantity and composition. Additionally, the transportation of C3DP wall panels can increase the offsite scenario’s total embodied carbon and energy beyond the on-site’s, depending on the number of truckloads, the material weight, and the shipping distance. Therefore, the sustainable adoption of offsite C3DP requires development of low-impact printable materials and the evaluation of these transportation metrics on a project-to-project basis. • 3D printing buildings offsite does not significantly increase embodied carbon and energy compared to on-site 3D printing • 3D-printed concrete walls have higher embodied carbon than the concrete masonry and wood-framed wall assemblies evaluated • Masonry walls including brick have the highest embodied energy • Transportation of wall assemblies 3D-printed offsite does not significantly impact the embodied environmental impacts at minimized shipping distances