A Conceptual Framework for the Design of Energy-Efficient Vertical Green Façades

Abstract

This research aims to develop a conceptual framework for a design support model for energy-efficient vertical green façade systems with a focus on their thermal and shading performance. The model applies forecasting and backcasting methods based on an extensive literature review and analysis by the authors, with a particular focus on the energy efficiency parameters of vertical green façades. The key parameters are related to the location (climate, surroundings, orientation of the façade), system type (air gap dimensions, irrigation, structure, and substrate type) and plant characteristics (leaf area index, leaf absorptivity, foliage thickness, stomatal resistance, typical leaf dimensions, leaf emissivity, transmission coefficient, radiation attenuation) determined from actual data collected from buildings. This holistic approach changes the perception of a user and an architect while facilitating the design process. The method’s limitations result from the scarcity of comparative experimental studies. However, the proposed model can be customised for specific conditions, with an increasing number of studies testing energy efficiency parameters comparatively. The article emphasises the vital importance of vertical green façades for built environment decarbonisation and links it to a new conceptual framework to encourage designers to make greater use of vertical green systems that are fully integrated into building energy strategies.