Renovation of old communities for public health and resilient environment based on greenery optimization and wind deflectors

Due to the global urbanization, the stock of older communities has been increasing drastically over time and living conditions have continued to deteriorate. Specifically, narrow building spaces and unreasonable community layouts would easily lead to the accumulation of air pollutants, which is more critical to public health as the recurrence of infectious diseases continues to be a threat to elderly residents. Thus, the need to improve and renovate the outdoor environment of old communities is urgent. This study proposes an environmental renovation strategy which explores the optimization of greenery and the application of wind deflector to improve the global and local wind environment. An old community in Suzhou, a national historical city in China, was selected as the case study. Based on field investigations, data measurement and comprehensive simulations, problematic areas were identified and renovation strategies were designed. As a result, the renovation achieved about 60% reduction of the vortex area and 40% reduction of the wind-free area, while also improving the green space ratio from 24% to 40.2%. The selection of greenery was also discussed regarding the antibacterial effect, carbon sequestration and air purification. A working flow chart has been synthesized for improving the outdoor environment of old communities.