Effect of Street Design on Outdoor Thermal Comfort in an Urban Street in Singapore

Outdoor thermal comfort in urban spaces is an important indicator of the quality of life in an urban environment. This paper attempts to investigate the effect of street design on outdoor thermal comfort in an urban street in the central business district in Singapore, focusing on the design variables of street orientation, height-to-width ratio (H/W), and vegetation. A comprehensive field measurement with multiple points is presented and used to validate a widely used computer software holistic microclimate modeling system. The significance of the research is that real field data from multiple measurement points on microclimate parameters are produced and the effect of street design parameters on outdoor thermal comfort is quantified. It is found in the paper that the NW-SE oriented street is more stressful than the NE-SW street in the afternoon in terms of thermal comfort in Singapore, and that a H/W of 3 can be considered a threshold with respect to outdoor thermal comfort. The paper concludes that the results presented can provide guidance for urban planners and designers to achieve optimized outdoor human thermal comfort. (C) 2015 American Society of Civil Engineers.