The Role of Urban Morphology and Pedestrian Movement in the Perception of Thermal Comfort in Historic City Centres: Spatial Sequences in Rome and London

Walking in the city affects the sensory realm of the pedestrian. Streets and squares in spatial sequences form a complex environment that enriches the thermal experience of pedestrians in movement. The variations that the latter perceive are not only spatial, but also microclimatic. The impact of microclimatic variations on thermal perception is challenging to measure. In particular, the link between the complexity of spatial sequences, the act of walking and the perception of thermal comfort in dense urban environments has not been studied sufficiently.

The present thesis has developed a new methodological tool that helps to fill this gap. This methodology starts from the process of ‘thermal walks’. These consist of a sense-walking technique that analyses the urban climate, the morphology of spaces and the way people perceive their combined effect, through a series of structured walks with simultaneous environmental and human monitoring. This new process is based on point-to-point evaluation of the thermal perception and spatial variation. Its particularity is the combination of objective microclimatic and spatial data with subjective responses by pedestrians at street level.

This methodology has been tested on site during fieldwork in the historic core of Rome and London during 2012 and 2013. This made it possible to compare results obtained from two spatial sequences in different climates in the temperate zone. Climatic mapping and design of a questionnaire for thermal walks helped to document the microclimate and variations in its perception. The resulting data was interpreted with statistical analysis and complex graphic representations of thermal variation in each spatial sequence. Findings reveal the role of streets and squares as spatial systems of thermal diversity, and shed light on some unknown characteristics of two of the most successful spatial sequences in Europe. The understanding of the thermal implications of spatial diversity is essential to develop site-specific design guidelines towards an evidence-based practice of sensory urbanism.