Re ECF Project: 2010-24

Project Title: The contribution of vertical greening on human bioclimate and carbon footprint in built environment

Applicant: Prof. CHU Lee Man of The Chinese University of Hong Kong

Total Approved Grant: $1,500,400

Duration: 15/10/ 2011 to 14/06/2014

Project Status/Remarks: Completed

The project aims to explore and evaluate the efficacy of vertical greening in reducing CO2 emission and improving human bioclimatic conditions. The project objectives are:

  • to develop a vertical greening solution that is economically attractive for massive deployment;
  • to evaluate the effect on indoor and outdoor human bioclimate at the proximity of vertical greenery surface;
  • to assess the capability of vertical planting in CO2 sequestration and urban carbon footprint; and
  • to enhance the public awareness and acceptance to vertical planting as an urban greening solution.

Summary of the Findings/Outcomes:
Although the carbon debt of vertical greening systems varies according to building materials, the results show that VGSs could offer positive environmental impacts, assuming the service time is long enough. The potential of vertical greening on insulation and cooling vary under different climates. This study demonstrated the thermal performance and energy saving of two VGSs in Hong Kong. The use of vertical greening in tropical and subtropical cities has greater environmental benefits in energy saving due to high average temperature. This study suggests that VGS is not only capable of energy saving and UHI mitigation, but also alleviating global warming. Apart from carbon sequestration and energy saving by vertical greening in its service life, other ecological benefits such as biodiversity conservation and dust removal for air improvement, though not quantified in this study, warrant further examination.