On the role of historical transitional spaces in counteracting urban heat island effect

Climate change is affecting cultural heritage sites globally. Despite progress, obstacles remain in adapting historical transitional spaces to present and projected climate hazards. Adaptation policies have emphasized the importance of built spaces and suggested mitigation measures for buildings. However, open and transitional spaces such as courtyards, cloisters, and porticoes are often neglected or underestimated. Transitional space is an area that acts as a connection between outdoor and indoor environments, serving as a buffer zone and a physical link. This study explores how these archetypal buildings can mitigate overheating in historical urban contexts and their impact on the Urban Heat Island (UHI), in comparison to the dense urban texture where they are located. The analysis focuses on building forms, proportions, and height-to-width ratios. The objective of this study is to investigate the thermal resilience of historical transitional buildings to withstand the effects of climate change, considering their typology, including spatial configuration and Height to Width (H/W) ratio, and the potential influence of urban form on the thermal performance of open spaces. Three different transitional spaces are selected according to their typology, geometry, and function. The research here presented integrates a typological analysis with a thermal microclimatic assessment conducted via Ladybug's tools to evaluate the ability of three selected case studies to withstand extreme temperatures and other environmental stressors. Parma, Italy, is a case study.