Drag Coefficient Limitations as Reference Parameter to Estimate Tangential Wind Load Affecting VGS

Vertical green systems (VGS) are emerging as an alternative to curtain wall for the design of building envelopes for retrofitting or new projects, since they are implemented to reduce and mitigate the Urban Heat Islands phenomenon and enhance biodiversity. The research opens with a reflection that raises questions and looks forward: if vegetation will assume a fundamental role as response of urban space threats, it will be necessary to manage all related aspects, including its design and consequently structural verification to comply with in the building field. However, currently no design guideline supporting designers addressing the structural response under wind actions is available. A more accurate estimation of tangential wind action affecting VGS might be considered at least as a baseline guide for designers, but a severe lack of studies about drag coefficient is highlighted. The author demonstrates after a literature review analysis, the limits if this aerodynamic coefficient would be implemented as design parameter and the gap of knowledge in the research existing.