Research on Energy-Saving Renovation and Energy Consumption Correlation of Historical Residential Districts under the Background of Urban Renewal: A Case Study of Hehua Tang District in Nanjing City

Abstract

Amid rising global energy demands and China’s shift toward urban stock optimisation, this study investigates low-carbon renewal strategies for Nanjing’s Lotus Pond Historical District using parametric modelling and energy simulations. Integrating Rhino/Grasshopper with a simulated annealing algorithm, multiple building height schemes were generated and evaluated for solar potential. Results demonstrated optimised schemes reduced energy use intensity (EUI) by 5.6–25 kWh/m² versus baseline. Shape coefficient strongly correlated with EUI (r=0.997), while floor area ratio (FAR) showed inverse correlation (r=-0.989). Vertical building distribution critically influenced solar gains, with self-shading reducing potential by 22%–28% in select cases. Balancing heritage preservation with energy performance, recommendations advocate limiting heights (1–2 stories), optimising shape coefficients (≤0.55), and integrating solar systems. The methodology offers data-driven insights for sustainable historical district renewal in stock-optimisation contexts.