Modular green walls: A sustainable architectural solution for energy efficiency in oceanic climates

Recently, green walls have increasingly been incorporated into building designs. They present a sustainable solution for both new constructions and retrofitting of existing buildings by reducing cooling energy requirements and enhancing overall thermal performance. However, there is limited information on the impact of living wall systems on building environments and their thermal performance in oceanic climates. This study fills this gap by assessing the thermal performance of modular living walls in La Rochelle, France, characterized by an oceanic climate. A prefabricated modular wall was installed on a house-like rectangular block, while a similar block without plant cover was used as a reference. External surface temperatures were measured to assess the effectiveness of the green wall in providing thermal insulation and its potential as a passive design strategy. The results revealed that the green wall significantly reduced surface temperatures by up to 15 °C compared to the reference wall during peak hours. Additionally, a numerical analysis was performed on a three-story building to compare its energy demands with and without green walls. The results indicate that incorporating green walls on the east and west façades notably enhances indoor thermal conditions, achieving a reduction in cooling load of approximately 64.38 %.