Sustainability, Vol. 11, Pages 4579: Green Facades and Living Walls--A Review Establishing the Classification of Construction Types and Mapping the Benefits (Sustainability)

The green facades and living walls of vertical greenery systems (VGS) are gaining increasing importance as sustainable building design elements because they can improve the environmental impact of a building. The field could benefit from a comprehensive mapping out of VGS types, an improved classification and nomenclature system, and from linking the benefits to a specific construction type. Therefore, this research reviews existing VGS construction types and links associated benefits to them, clearly differentiating empirical from descriptive supporting data. The study adopted a scoping research review used for mapping a specific research field. A systematic literature review based on keywords identified 13 VGS construction types—four types of green facades, nine types of living walls, and ten benefits. Thermal performance, as a benefit of VGS, is the most broadly empirically explored benefit. Yet, further qualitative studies, including human perception of thermal comfort are needed. Improvements in air quality, reduction of noise, positive effects on hydrology, and visual benefits need much further empirical testing, as the current supporting data is mostly descriptive and based on the similarities with green roofs. The educational benefits of VGS has no supporting empirical evidence, while the social benefits have only been empirically evaluated through one identified study. Future progress of the field depends on the adoption of a clear VGS nomenclature system and further qualitative and quantitative empirical testing of VGS benefits, which should be clearly linked to a specific VGS construction type so that cross-comparison of studies is enabled.