Toward Low-Carbon and Cost-Efficient Prefabrication: Integrating Structural Equation Modeling and System Dynamics

Against the backdrop of the ongoing implementation of the “dual-carbon” strategy and green building policies, this study concentrates on the production stage of precast concrete (PC) components. A composite analytical framework that integrates the structural equation model (SEM) with the system dynamics model (SD) is developed, through which a systematic and dynamically responsive model for the joint optimization of carbon emissions and costs is proposed. The results demonstrate that (1) when investment in green policies is maintained within the range of 10–20%, a 4.2% reduction in carbon emissions can be achieved by 2030, while costs remain optimized; (2) under the scenario of moderate green policy investment (10–20%) combined with a carbon tax of CNY 100/ton, carbon emissions can be reduced by 7.52%, with costs also reaching an optimal level; and (3) among the multi-path emission reduction strategies, the technology optimization pathway and energy structure optimization pathway achieve reductions of 9.68% and 8.97%, respectively. These findings provide theoretical support for the coordinated control of carbon emissions and costs during the production stage of PC components, while also offering empirical evidence and practical guidance for governments in formulating green building policies and for enterprises in advancing low-carbon transitions.