Impact of post-socialist vertical extensions of buildings on outdoor microclimate in collective housing areas: A study of Niš, Serbia

Abstract

Extensive transformations of large housing estates in postsocialist cities have been the subject of many studies. However, the effects of transformations resulting from urban densification, upon local microclimate, have not been fully determined. This paper addresses this issue by investigating the implications that vertical extension of residential buildings had on microclimatic parameters of thermal comfort (air temperature, mean radiant temperature, wind speed, relative humidity, solar radiation) in three large housing estates in the city of Niš, Serbia. By using ENVI-met software, outdoor microclimate is simulated in two scenarios: (1) original urban setting and (2) current urban setting, after the upgrade of existing buildings with additional floors. For the scenario with upgraded buildings, results indicate a small decrease in daytime air temperature, and small increases in mean radiant temperature and nocturnal air temperature. The effects on air temperature, relative humidity and solar radiation are more visible when upgrading low-rise structures, while the upgrade of high-rise buildings mostly affects wind speed. Research identifies tools and strategies of urban design that help in adapting inherited urban settings to temperature increase, such as positioning vertical extensions to exploit the effects of shading, conceptualizing open space in regard to building form, wind speed and solar radiation, and capitalizing on the cooling potential of trees.