Research on Green Roof Design Strategies for High-Density Old Residential Areas Based on Thermal Environment Optimization

With the rapid development of China's cities, the urban heat island effect has intensified, and the habitat environment problems of old residential areas are becoming increasingly severe, unable to meet the residents’ demand for a healthy and comfortable life. Rooftop greening, an important initiative to improve urban habitat, can effectively alleviate the urban heat island effect and reduce energy consumption simultaneously. According to the characteristics of old residential areas, this paper focuses on extensive green roof strategies by taking Tongji Workers’ Village in Shanghai as an example. It quantitatively simulates and analyzes the regulating effect of extensive green roofs on the indoor and outdoor thermal environment of old residential areas with GBSWARE, which is a building environment and energy consumption simulation software. The HVAC load for energy-saving is compared and analyzed before and after implementing green roofs. The results show that by greening 90% of the roof of Tongji Workers’ Village, the overall average heat island intensity of the settlement decreased by 20%; the heating and cooling energy consumption of the building units decreased by 3.05% and 3.09%, respectively. This paper integrates domestic and international green roof technologies to explore the potential of photovoltaic power generation in green roof implementation, simultaneously achieving the goal of optimizing the thermal environment of old residential areas and reducing heating and cooling energy consumption. The results of this analysis demonstrate the optimization effect of lightweight, extensive green roofs on the indoor and outdoor living environment of old residential areas through multi-dimensional visualization mappings. The results of this paper provide a design basis for promoting green roof technology in high-density old residential areas.