The impact of densification and orientation manipulation on outdoor thermal comfort at social housing in arid regions: a sensitivity analysis

Abstract

Many developing countries are experiencing rapid urban growth, resulting in a high demand for social housing schemes. In Egypt, newly built communities and potential extensions are incompatible with its hot climate due to low aspect ratios, high sky view factors values (SVF) and less shaded areas, which negatively affect outdoor thermal comfort at the pedestrian level. This study aims to find a relationship between density (represented in SVF), Physiological Equivalent Temperature (PET) and orientation through a sensitivity analysis to improve the thermal comfort of outdoor spaces in new cities. The research was held on the peakiest summer day using a validated ENVI-met simulation model for a residential area in New October city. The simulation results of 36 scenarios with a total of 37,138 spatial grids were examined through sensitivity analysis to quantify the impact of densification parameters like building coverage ratio, floor area ratio, building height variation, and orientation on PET. PET was found to be more sensitive to densification in cardinal directions. With Higher mid-range densities PET at cardinal orientation reached up to 10℃ higher than in diagonal. Also, the results revealed that optimizing density and building heights could improve average PET (08:00 to 18:00) in diagonal orientation with up to 8℃ in the mid-range densities. However, orientation is insignificant in low densities. Out of the tested parameters, densification was found to be the most impactful strategy than height variation. These results can aid in developing public and private housing schemes that are more climate responsive.