Depending on the type of system and the climate, our research indicates that vertical greenery systems (VGS) can reduce surface temperatures by 2.5–7.3°C. In dry regions, modular systems are roughly 30 % more effective at cooling than felt-based systems. A major sustainability issue can be addressed by using smart irrigation techniques, which can cut water use by 38–59 % while preserving thermal advantages. According to the biodiversity evaluation, groups of native plants support 2.3 times more biodiversity than only decorative plants, and having more plant species—from 5 to 20—can result in a 175 % increase in pollinator visits and a 240 % increase in arthropod populations. Regional differences exist in implementation issues; technical difficulties are 40 % more significant in tropical countries than in temperate ones, while economic barriers are ranked highest in North America and Southeast Asia. Compared to prescriptive methods, performance-based policies had 65 % higher implementation rates, indicating a potential avenue for more successful incentive schemes. This study makes three novel contributions: (1) first systematic comparison of irrigation strategies for VGS water sustainability, demonstrating 38–59 % water savings while maintaining > 90 % of thermal benefits—resolving a critical sustainability tension previously unquantified; (2) first linkage of VGS plant diversity to pollinator activity, showing 175 % increase in pollinator visits with diversity increase from 5 to 20 species; (3) first multi-climate, multi-typology comparative assessment in China. The research agenda highlights cost-cutting measures, drought-tolerant plants, and climate-resilient systems as top priorities for further study. For designers, legislators, and property owners looking to optimize the environmental advantages of vertical greenery in various urban contexts, these findings offer evidence-based recommendations.
Bi et al. (Wed,) studied this question.