Numerical evaluation of the use of vegetation as a shelterbelt for enhancing the wind and thermal comfort in peripheral and lateral-type skygardens in highrise buildings

Skygardens or skycourts are a unique architectural intervention in the built environment, enhancing the social, economic, and environmental values of the building. It allows occupants to connect and experience outdoor freshness within a semi-enclosed environment. However, skygardens located on a highrise building may generate intense wind gusts, endangering the safety of occupants. Using a validated computational fluid dynamics model, this study investigates the potential of various vegetative barriers or shelterbelts in attenuating the high wind speeds encountered in such spaces and the impact on wind and thermal comfort. Three skygarden configurations were investigated with and without vegetative barriers, simplified and modelled as porous zones, and their effect was studied on the velocity and temperature profile at the occupants’ level. The results indicate that while hedges and trees can offer resistance to airflow, trees provide higher temperature reduction. However, a combination of vegetative and geometrical barriers provides the most optimal condition in the skygarden. The study has identified the importance of assessing wind attenuation characteristics of tree plantations on highrise skygarden, and the results can be used in designing intervention strategies. Moreover, vegetation can attenuate pollutants and mitigate poor air quality by surface deposition, and future studies should investigate in that direction. ELECTRONIC SUPPLEMENTARY MATERIAL (ESM): The Appendix is available in the online version of this article at 10.1007/s12273-022-0943-7.