Lessening the energy usage of buildings: an exploration into green walls’ practicalities

The article provides insights into green walls’ potential and energy-saving mechanisms in Melbourne, Australia. The use of vegetation on a building’s façade has been shown to positively affect the building’s demand for heating and cooling and a range of additional benefits. A mixed research study has been developed to explore and quantify using vegetated façades as a feasible option for reducing energy usage in commercial buildings. These results show that a green wall of building construction holds a similar level of thermal resistance as a 2.5 cm layer of expanded polystyrene building insulation, at an R-value of 0.38 m²K/W. Combining this calculation with speculations as to the benefits of shade, evapotranspiration, and wind production has produced data showing a typical green wall can reduce the energy usage of a commercial building by up to 12%. This figure supports the use of vegetated façade systems to reduce energy usage in the built environment. This study can be instrumental in raising awareness for building and property professionals, as well as occupants, of the positive effects of green (vegetated) walls on the façades of buildings as a viable option for reducing heating and cooling loads and, consequently, reducing spending on energy usage.