Towards Climate-Resilient Vertical Green Façades: A Review of Emerging Shading Technologies and Design Challenges

This study investigates shading technologies used to protect vertical green façades (VGF) from excessive solar exposure and climate-related stresses. A scoping review of 176 publications from the past decade was conducted, focusing on innovative materials and components applied in adaptive and passive shading systems relevant to Central and Southern European climates (BSh, Csa, Csb, Cfa, Cfb, Dfb). Only technologies that reached at least the prototype or small-scale trial stage were included. The review identifies several categories of emerging adaptive solutions—such as smart materials, pneumatic systems, PCM-integrated, PV-integrated, algae-based, hygromorphic, electro-optic, fluidic, and mechanical or mechatronic devices—which show potential to improve microclimatic regulation and user comfort, though their long-term durability and integration with VGFs remain insufficiently documented. Advances in digital fabrication and optimisation support the development of high-performance passive elements, while experimental and simulation studies indicate that dynamic shading can offer promising outcomes across diverse climatic contexts. To strengthen the plant-centred perspective, each shading category is evaluated through four criteria: PAR transmission, microclimatic regulation, evapotranspiration behaviour, and integration constraints. Climate projections suggest that radiation and heat stress may increasingly challenge certain VGF species in warmer regions, highlighting the need for shading strategies aligned with plant requirements, local conditions, user needs, and long-term maintenance.