Climate Adaptability and Energy Performance in the Greater Bay Area of China: Analysis of Carbon Neutrality Through Green Building Practices

China has committed to carbon neutrality by 2060 by necessitating a comprehensive transformation of its building sector, particularly in rapidly urbanizing areas such as the Greater Bay Area (GBA), where subtropical climates, urban heat island effects, and extreme weather events present distinct challenges for achieving carbon reduction objectives through green building practices. The goal of this study is to establish an analysis method for green building success in the GBA’s subtropical environment, paying attention to the challenging goals of reducing carbon and making buildings more climate-resilient. Research techniques involved performing building energy simulations with EnergyPlus and DesignBuilder, applying LightGBM models for machine learning, using case studies from 32 buildings in Shenzhen, Hong Kong and Guangzhou and carrying out an evaluation of the policy using a PEI. Energy usage in green buildings was 45.3% less than in conventional structures, with Energy Use Intensity ranging from 65.1 to 72.4 kWh/m2/year, while traditional buildings used between 118.5 and 124.2 kWh/m2/year. Also, the carbon footprint during the life cycle of buildings was decreased by 38.4% and they became more resilient to typhoons, giving residents 72.4 h of power during storms, while conventional buildings gave only 8.3 h. HVAC system efficiency was the leading factor, accounting for 24.3% of the difference in energy performance. A detailed approach is developed for optimizing subtropical green buildings, based on unique design features and helpful policy ideas to promote carbon neutrality in swiftly growing metropolitan areas around the world.