Evaluation of Gaps in Life Cycle Sustainability Assessments of 3D Concrete Printing: A Systematic Literature Review and Recommendations

: The construction industry significantly contributes to global carbon emissions, resource depletion, and environmental degradation, necessitating sustainable innovations. 3D concrete printing (3DCP) has emerged as a transformative technology offering design flexibility, reduced material waste, and improved efficiency. However, sustainability assessments of 3DCP remain fragmented. This study systematically reviews 23 articles published between 2010 and 2024, revealing that Life Cycle Assessments (LCA) predominantly focus on carbon footprint and energy consumption, while other impact categories are underexplored. Life Cycle Costing (LCC) is often limited to material costs, excluding long-term economic factors. Social Life Cycle Assessment (S-LCA) is notably absent, with only one study addressing social implications. Methodological inconsistencies in functional units and system boundaries hinder comparability. The study calls for harmonised frameworks integrating LCA, LCC, and S-LCA under standardised guidelines. These findings contribute to advancing robust sustainability methodologies and support the adoption of 3DCP as a viable solution for sustainable construction.