Optimizing sustainable retrofit strategies for a heritage complex through multiobjective optimization and Space Syntax analysis: a Suzhou case study

Abstract This study addresses the sustainable retrofitting of heritage buildings, balancing modern efficiency with heritage preservation. Using a Suzhou case study, this research integrates multiobjective optimization and Space Syntax analysis to tailor sustainable retrofit strategies for a heritage complex. The framework balances energy efficiency, historical value, and architectural integrity by customizing measures for individual buildings. The proposed solution reduces energy consumption by up to 37% with lower negative historic impacts and initial costs compared with solutions proposed by conventional optimization methods. These results demonstrate that advanced optimization combined with spatial analysis provides a robust, quantitative basis for harmonizing energy performance with heritage conservation.