Green façades and climate resilience: A comparative analysis across retrofit scenarios for an Italian building archetype in two representative climatic contexts

Accounting for 32% of global energy consumption, buildings not only impact climate change but are also affected by it. To address these challenges, in addition to decarbonising the building stock, there is a need to implement climate-resilient solutions that enhance climate adaptation. The proposed study explores the energy efficiency and climate resilience of non-traditional solutions like green façades for a representative Italian residential building archetype in two distinct climate zones, Rome and Turin, under current (2020s) and projected (2050s and 2090s) climate scenarios. The green façade is analysed using a detailed calculation tool implemented within the EnergyPlus (version 23.2) energy simulation software. The analysis covers both existing buildings without insulation and buildings retrofitted with insulation, solar shading, and ventilative cooling. Results indicate that green façades—particularly when applied to multi-orientations of the building—can significantly reduce cooling need and overheating in pre-retrofit buildings, with reductions of up to 59% and 85%, respectively. In retrofitted buildings, green façades offer additional benefits beyond standard retrofit packages, with further cooling need reductions of up to 24.7% and decreasing overheating by up to 54.8%. Although their relative effectiveness generally declines with climate change due to rising temperatures and reduced plant evapotranspiration, green façades continue to provide relevant benefits even under the 2090s scenario. A comparison between the two climate zones reveals greater cooling reductions in Rome due to higher summer heat loads and lower winter heating penalties. These findings underscore the green façade potential as a passive design strategy to support the transition towards more sustainable and climate-resilient residential buildings.