The efficacy of roof-based adaptations to reduce heat stress exposure in informal dwellings

Abstract

While climate change represents a universal threat to the sustainable growth efforts globally, its impacts are not experienced equally with marginalised population groups, especially informal settlement residents, being highly exposed to its negative effects. Despite being widely acknowledged that the built environment is a major driver of inhabitants’ exposure to climate change-related hazards, limited research has been undertaken on developing heat stress adaptation measures for informal settlements in Southern Africa. Furthermore, Africa’s projected rapid urbanisation and limited adequate housing provision point to a significant growth of informal settlements, particularly within the Southern African context. The dearth of available information on household level climate change adaptation in informal settlements prompted this study to investigate the efficacy of roof-based adaptation strategies to lower heat stress exposure in informal dwellings in Tshwane, South Africa. As an explorative study with a quantitative focus, the study uses a digital simulation research design to assess the efficacy of four climate change adaptation strategies to lower heat stress exposure in two typical informal dwellings as case studies. While informal settlements have diverse building typologies, informal dwellings – frame structures cladded with steel sheeting without any thermal insulation – are widely used and highly vulnerable. In contrast to typical adaptation measures proposed for informal dwellings, the main findings highlight the benefit of high thermal mass coupled with shading strategies to lower thermal amplitudes and lower excessive heat stress exposure. Consequently, the article contributes to the current climate change adaptation discourse, in particular its application in informal settlements.