The influence of building form variables on the environmental performance of semi-outdoor spaces. A study in mid-rise and high-rise buildings of Singapore

Abstract

This study delved on the role of semi-outdoor spaces (SOS), as form-based strategies, in providing enhanced, thermally comfortable environments in highly dense urban contexts. A sample of sixty-three (63) SOS was studied, within four different mid-rise and high-rise buildings located in the warm-humid tropical city of Singapore. It was found: (i) that SOS may act as thermal buffer spaces; (ii) that microclimate creation in SOS is linked to form, specifically to geometrical variables such as void-to-solid ratio, height, height-to-depth ratio, height from ground level, green plot ratio and open space ratio, which influence significantly the environmental factors of air temperature, mean radiant temperature, air velocity and relative humidity; (iii) that some aforementioned geometrical variables (height-to-depth ratio and open space ratio) are linked to thermal comfort when estimated with SET* and PMV* thermal indices; (iv) and that thermal comfort (between −1 and +1 PMV*) can be achieved in SOS considering a typical Singaporean outdoor CLO of 0.3, especially for 1 MET (85.7% of SOS). In the context of Singapore, this study demonstrates that incorporating SOS to mid-rise and high-rise building forms promotes the creation of thermally comfortable microclimates suitable for human activity, even during the hottest hours.