AbstractWith large-scale urbanization globally, the world is facing environmental problems brought about by high-density cities. To achieve sustainable development in Hong Kong, especially for the heavily loaded Cross Harbour Tunnel district, The Hong Kong Polytechnic University proposes a Green Deck over the Cross Harbour Tunnel to enhance the neighboring environments. Green belts, buildings, and a new exhibition center are planned for this deck. This will require an increase in the guest capacity of nearby hotels in the Tsim Sha Tsui East (TSTE) area. This study, therefore, investigated the development potential of the 23 existing buildings in TSTE and the environmental impact brought about by the increase of plot ration (PR)/building height (BH) in that area. Spatial analyzes of solar exposure, wind ventilation, and air temperature were conducted based on four different scenarios with various PR/BH; human thermal comfort brought about by PR/BH changes were also measured. A comparison of different scenarios revealed no significant changes in the surrounding environment. The study concludes that there is potential for PR/BH relaxations in TSTE to increase spaces to meet increased population flow.