Towards synergistic effect: spatiotemporal evolution and convergence of construction waste and carbon reduction efficiency

The spatiotemporal evolution and convergence of construction waste and carbon reduction (CWCR) in the regional construction industry can optimize the spatial allocation of production factors among different regions and promote sustainable development in the construction industry. The three-stage SBM-DEA model was used to measure the CWCR efficiency in construction industry, we analyze the spatial differences, decomposition, and dynamic evolution on CWCR efficiency. The overall CWCR efficiency of the construction industry showed a gradual increase, with a pattern of “Central-Northeast-West-East”. The Gini coefficient of CWCR efficiency was lower, with an average of 0.141. The highest degree of intra-group differences was in the eastern region, and the lowest was in the central region. The inter-group density difference was the main source of the increase in CWCR efficiency. The interaction between inter-regional and intra-regional differences increased over time. The phenomenon of multi-polarity in CWCR efficiency patterns weakens overall; all regions exhibit β absolute convergence and β conditions convergence except the Northeast. The Central region shows a positive spatial spillover effect, while the Eastern region has a negative spatial spillover effect. The difference in the number of scale construction enterprises was the fundamental factor. The findings provide valuable insights for the sustainable development of the construction industry and offer a scalable framework for regional sustainable development strategies.