Ensiyeh Farrokhirad

The rise in energy-efficient building strategies, driven by the intensifying energy crisis, has encouraged the development of the passive house (PH) approach. However, existing research highlights a potential downside, the perception of the overheating risk in hot periods, particularly when design and construction methods fail to incorporate adequate mitigation strategies. This study examines the pressing necessity of addressing overheating risks in PHs through a systematic review. The aim is to identify key factors reported as contributing to overheating, to evaluate recommended solutions across diverse global regions, and to identify methods to reduce the risk. This review indicates that PHs are considered at risk of overheating in the hot periods of the year across many climatic regions, exacerbated by the impacts of climate change. Architectural features, climate conditions, inhabitants’ behaviors, and perceptions of the quality of indoor spaces are important factors affecting PH overheating and should be considered at the design stage. It is concluded that the urban context, building envelope characteristics, and their impacts require greater attention. Based on the knowledge gaps identified, green walls are proposed as a nature-based solution with good potential for mitigating overheating in PHs. More integrated consideration of all factors and solutions can minimize current and future risks.

Living walls are a nature-based strategy to enhance climate resilience in urban areas. There is a need to study the possible influence of living walls on the thermal performance of building façades, given the rising temperatures in 2022 across the UK. This study aims to analyze the impacts of living walls on façade temperature based on orientation variation through simulation Envi-met 5.0.3. software. The living wall studied is attached to a multistory building located in Manchester city center consisting of seven evergreen plants. An environmental simulation was carried out linked to the 2022 climate, including extremely hot and cold days. Four scenarios of façades with and without greening on the northwest and southeast orientations in summer and winter were analyzed. The results highlighted the living wall’s ability to reduce the surface temperatures on both the northwest and southeast façades on a hot summer day. There is no significant evidence of improvement for the northwest façade in the winter climate, but a modestly increased temperature is shown in the southeast compared to the bare wall. These findings indicate that living walls provide measurable advantages in the building envelope, leading to energy saving.