Human-centered insights into outdoor thermal comfort adjacent to green walls: a systematic literature review

Purpose Recently, studies on the effect of green walls (GWs) on outdoor thermal comfort (OTC) have received more impetus, and there is an increasing demand for systematic analysis to comprehend this strategy and pinpoint any shortcomings. The aim of this study is to understand how GWs affect thermal comfort, identify gaps and expedite the exploration of novel research paths by presenting a conceptual model. Design/methodology/approach This study conducts a systematic literature review, following the PRISMA guidelines, regarding the effect of GWs on OTC conditions. By elucidating the dynamic interaction between subjective thermal perception and environmental parameters, this review offers valuable insights for advancing research and practice in climate-responsive design. Findings Findings indicate that, of the 162 studies reviewed – originally identified from 1,014 articles retrieved through keyword searches in the Web of Science and Scopus databases – only 23 specifically addressed the OTC effects of GWs. Despite individuals being principal users of outdoor spaces, their thermal experiences, sensations, preferences, satisfaction and acceptability are rarely taken into account in these studies. Accordingly, this review emphasizes the need to integrate psychological analyses alongside physical-physiological assessments to achieve a comprehensive understanding of thermal comfort in the context of GWs. Originality/value To date, no study has specifically examined the fundamental parameters required to assess human thermal comfort in proximity to GWs. While previous research has primarily focused on physical measurements, a critical gap remains in understanding how individuals perceive and interpret thermal conditions in such environments. This systematic review addresses this gap by synthesizing existing evidence and proposing a conceptual model. Additionally, a proposed questionnaire is suggested to support future human-centered investigations.