Opportunities stemming from retrofitting low-resource East African dwellings by introducing passive cooling and daylighting measures

This paper models the retrofitting of traditional rural dwellings in Uganda by introducing passive cooling and daylighting measures. With climate change, outdoor temperatures in parts of the Global South will become unbearable. Communities will be forced to spend more time indoors and thus require further cooling and daytime lighting for thermal and visual comfort. Passive measures can address this while also attenuating energy consumption and diversifying energy use. For the first time, these measures are combined and modelled for those purposes in a rural developing country context where there is limited access to electricity. Using SketchUp and EnergyPlus™, we simulate 15 scenarios of passive cooling and daylighting measures for two baseline scenarios: electrified mud hut and semi-permanent dwelling. Those are also feasible scenarios for similar greenfield unelectrified architectures. The results from the simulated scenarios on electrified dwellings include energy savings, and from these, payback periods are calculated. Two cost-effective scenarios are identified. For mud huts, combining shading (through vegetation) with a centralised fibre optic solar concentrator enables an annual reduction of 31 % of energy consumption. For semi-permanent dwellings, painting rooftops white combined with the integration of solar water light bulbs reduces energy consumption by 47 %. In terms of payback periods for the selected scenarios, the former is four years and nine months, while the latter is two months.