Vertical Greenery Systems: A Review of Thermal Performance

Facade greening has been extensively used in several buildings worldwide. The benefits of Vertical Greenery Systems (VGSs) have been well-documented and researched; however, studies on the thermal performance of these systems have identified a number of gaps that need to be addressed. To address this issue and conduct further studies in this direction, this paper presents a comprehensive review of the high-impact research conducted in this domain over the last 2 decades. A literature review was conducted to examine the current standing in this research area and to identify potential knowledge gaps. This review establishes that the thermal performance of VGS is the most commonly studied aspect; however, these studies lack cohesion and replicability. The appropriate application of VGS to a building envelope has proven to be advantageous in terms of energy savings, while significantly enhancing and managing the microclimate surrounding the built environment by neutralizing the solar influence. It is clear from the research that the thermal performance of these systems depends on a variety of factors that are specific to the climate zones and microclimates of the sites in which they are installed. A brief bibliometric analysis was also performed to identify potential knowledge gaps and scope for further research, showing the crucial need to study these greening systems in the Indian context because of the lack of context-specific studies for the region.