Building Performance Simulation and Climate-Adaptive Green Retrofit of Jingzu Jiashu, a Historic Chaoshan Residence in Lingnan Under Hot–Humid and Disaster-Prone Weather Conditions

Historic residential buildings in Lingnan are affected by hot–humid and disaster-prone weather conditions, including high temperature, high humidity, intense solar radiation, monsoon winds, and typhoon-related climate stress, which challenge indoor thermal comfort, daylighting, natural ventilation, and adaptive reuse. Taking Jingzu Jiashu, a historic Chaoshan residence associated with overseas remittance culture, as a case study, this study develops a simulation workflow for climate-adaptive green retrofit. Digital documentation, architectural survey, material investigation, and climate data were integrated to establish a baseline model. PMV, DA300, and ACH/ACR were used to evaluate thermal comfort, daylighting, and natural ventilation. The baseline results show summer overheating, insufficient daylighting in deep rooms, and inadequate ventilation in representative rooms. Comfortable hours accounted for only 7.29–7.78%, thermally uncomfortable hours reached 42.84–51.53%, and the maximum PMV reached 4.65 in the rear hall and 3.54–3.65 in representative rooms. The effective daylight areas of the front and rear rooms were approximately 40% and 31%, while baseline ACH values ranged from 1.06 to 1.89 h−1. An integrated retrofit strategy was proposed, including functional reorganization, envelope optimization, opening adjustment, ventilation-path organization, and courtyard/transitional-space improvement. After retrofit, comfortable hours increased to 32.00–42.45%, thermally uncomfortable hours decreased to 17.25–21.28%, maximum PMV values decreased to 1.82–1.86, daylight areas increased to 81% and 74%, and ACH values rose to 2.97–4.49 h−1. The results indicate that building performance simulation can provide quantitative support for climate-adaptive green retrofit of historic Chaoshan residences in Lingnan, offering a methodological reference for healthier, lower-carbon, and more resilient reuse of similar historic dwellings.