Impact of Urban Block Typology on Microclimate Performance in a Hot-Humid High-Density City

Abstract

Because of their structure, urban areas induce very complex climate phenomena while notably impacting pedestrian safety and comfort in the urban microclimate. This paper presents the results of an investigation into the influence of urban block typology and building intensity on environmental performance in the context of the urban microclimate of a hot-humid high-density city. Qualitative and quantitative characterization of the building geometries used in this study was conducted to compare an existing block typology scenario with five new block typology scenarios in an area of 350 x 350 x 150 (L x W x H) meters. The scenarios investigated were composed of different settings for floor area ratio (FAR) and building coverage ratio (BCR) and different configurations of building elements (tower, podium, and courtyard). They were simulated and analyzed using the ENVI-met software. The simulation results indicate that the five new scenarios all improved the environmental thermal parameters and that the FAR has a greater influence than the BCR. FAR has the strongest correlation with air temperature, followed by solar radiation and relative humidity. The influence of BCR on humidity and wind speed is not as significant as that of FAR. A tower strongly influences wind speed in proportion to the height of the building. Open courtyards correlate with higher temperature and lower humidity than closed courtyards. The combination of a closed courtyard with a hybrid block consistently outperformed the other configurations in thermal performance. Within this framework, the proposed scenarios can provide recommendations for city design regulations and input for urban design methods to further improve microclimate performance.