Quantifying embodied carbon reductions through mixed reality integration in prefabrication: A Monte Carlo-enhanced life cycle approach

The construction industry produces a large amount of carbon emissions, with a significant portion attributed to embodied carbon (EC). Prefabrication has the potential to reduce EC through streamlined workflows and controlled production environments. However, inefficiencies such as rework, material waste, excessive labor input, and quality issues can offset these benefits, necessitating a flexible digital technology approach. This study proposes the integration of mixed reality (MR) into prefabrication workflows to mitigate these issues and reduce EC emissions. A hybrid input-output (I-O) life cycle assessment (LCA) model combined with Monte Carlo (MC) simulation was employed to evaluate EC emission under uncertainty. Four prefabrication scenarios representing increasing levels of MR integration, ranging from conventional methods to high-level digitalization, were analyzed across several life cycle stages. Results emphasize that EC emissions were reduced by 8.5%, 14.9%, and 21.2% in the Lower, Medium, and Higher MR scenarios, respectively, due to significant reductions in rework, rejections, labor hours, and energy use. MC simulation confirmed the robustness of the results, showing decreased variability and tighter confidence intervals with higher levels of MR integration. While the experimental context focuses on precast panel production, the proposed approach is generalizable to broader prefabrication systems with appropriate adaptations to the MR model. This study contributes to the body of knowledge by introducing a novel integration of MR with hybrid I-O LCA for EC accounting in prefabrication and by demonstrating how MC simulation enhances the reliability of environmental impact assessments under uncertainty. The proposed hybrid I-O LCA approach offers a replicable and data-driven method for sustainable decision-making in construction engineering and management.