Outdoor living. The impact of urban materials and morphology on pedestrians thermal and visual comfort- a state of the art review and discussion

While urban areas expand both in terms of population and built/paved surfaces, cities are facing growing challenges. In particular, the wellbeing and comfort of urban population is of primary importance, and has to be pursued together with other objectives, such as the reduction of energy consumptions and emissions. These issues are all related, since energy consumptions lead to higher emissions, which translate into higher temperatures in cities, thus reduced thermal comfort for pedestrians, and air quality deterioration. While solutions to reduce energy consumptions in buildings have been widely studied, in terms of both technological solutions and urban morphology, their effects on the outdoor areas have been often neglected. In this preliminary work, the purpose is to investigate thermal and visual comfort of pedestrians living the outdoor areas of the city, by taking into account the effect that (i) materials, (ii) morphology and then (iii) materials and morphology together has on it. The state of the art on each of these topics is considered, and then a comprehensive overview, analysis and discussion are carried on. Outdoor thermal comfort indicators and standardization issues and possible future developments are finally discussed. This work aims to highlight that, while energy consumptions reduction and indoor thermal comfort are of fundamental importance, solutions and strategies cannot leave aside their effects on the outdoor areas, which are where the large part of mankind social life and living takes place and for this reason need to be safeguarded.