BIM Reverse Modeling and Performance Optimization for Low-Carbon Retrofitting of Existing Buildings Powered by Smart Construction

Driven by the dual objectives of carbon peaking and carbon neutrality alongside technological innovation in smart construction, low-carbon retrofitting of existing buildings has emerged as a pivotal pathway for the construction industry’s green transformation. As a digital platform, Building Information Modeling (BIM) provides essential support through its reverse modeling technology for precise reconstruction of physical information in existing structures. However, current challenges in modeling accuracy and performance optimization coordination have constrained the enhancement of retrofitting efficiency. This study focuses on smart construction technology, integrating 3D laser scanning and point cloud processing into BIM reverse modeling to establish a closed-loop system encompassing “intelligent data collection—BIM reverse modeling—low-carbon performance simulation—intelligent optimization decision—solution output.” Through a multi-technological integrated reverse modeling process and dynamic linkage between BIM and energy consumption simulation, empirical research was conducted across existing building retrofit projects in Shenzhen, Beijing, and Guizhou. Results demonstrate that following this technical approach, building energy intensity decreased by 15%-25%, while carbon emissions per unit area dropped by over 18.7%. The Guizhou project achieved net-zero carbon emissions through passive design and photovoltaic system integration, validating the methodology’s feasibility. These findings provide technical support for precision and intelligent retrofitting of existing buildings, offering significant practical value in advancing carbon neutrality goals within the construction sector.