The effect of planning design on thermal comfort in outdoor spaces

Urban outdoor spaces are considered essential elements of cities, where the greatest amount of human contact and interaction takes place. That is the reason why there is increasing public interest in the quality of open urban spaces as they can contribute to the quality of life within cities, or contrarily increase isolation and social exclusion. There are a lot of factors influencing the success of the outdoor spaces; one of the principal factors is the microclimatic comfort. In the hot areas, the outdoor thermal comfort conditions during the daytime are often far above acceptable comfort standards due to intense solar radiation and high solar elevations. The variation of the urban spaces' configuration can generate significant modifications of the microclimatic parameters. Design decisions such as street and sidewalk widths, shading structures, materials, landscaping, building heights, and inducing air flow have a significant impact on the pedestrian thermal comfort and subsequently on the use of the urban environment. Although it has been established that the vegetation elements should be considered as one of the main tools that can be used in improving the thermal comfort in outdoor spaces, the integration of the climate dimension in the planting design process in urban spaces is lacking because of insufficient interdisciplinary work between urban climatology, urban design and landscape architecture. The primary aim of this research is to study the influence of some of the design decision for the plantation elements in outdoor spaces on the thermal comfort of its users. This will provide landscape designers and decision makers with the appropriate tools for effectively assessing the development of urban environment while considering the microclimate of outdoor spaces. A special emphasis is put on summertime conditions in Egypt. Findings of this research will contribute to sustainable urban design of outdoor spaces.