ZEMCH 2015 - International Conference Proceedings | Page 616

1. Introduction Located in East Africa, Uganda occupies an area of 241,038 square kilometres (Byakola 2007) and has an estimated population of around 39 million (UNDESA 2014). The climatic conditions in Uganda vary greatly from hot arid climate to tropical equatorial uplands. Local climates also vary greatly depending on the altitude and rainfall (EMI 2012). Overall, Uganda has a tropical climate, moderated by an average altitude of 1100 meters above the sea level (ACTwatch Group and PACE/ Uganda 2013), with two rainy seasons and mean annual rainfall of 750-2000mm (Byakola 2007; UBOS 2006). The mean annual temperature of the most parts of the country varies between 16 °C and 30 °C; however, Northern and Eastern parts of the country may experience temperatures higher than 30 °C and the temperature in South Western part may get below 16 °C (UBOS 2006). The average temperature in East Afr ican countries is estimated to increase by 3-4 °C during the next 70 years due the global warming (EMI 2012). The current situation has raised concerns over thermal comfort conditions of Ugandan low-income populations the majority of whom live in overcrowded and poor quality houses with very limited or no access to basic facilities. In fact, due to their vulnerable living conditions, low-income people will be hit the worst by the consequences of climate changes. Around 38% of Uganda’s population live below the international poverty line of $1.25 a day and more than 60% of the country’s urban population live in slums (Malik 2014; EPRC 2013). Furthermore, only less than 15% of Ugandan households have access to electricity. The situation is much more critical in rural areas as only around 5% of rural households have access to electricity compared with around 55% in urban areas (UBOS 2012). This is while around 85% of the population lives in rural areas (UN-HABITAT 2009). In fact, considering the negligible operational energy (space heating and cooling) of low-income housing sector, embodied energy is currently the key factor in evaluating the environmental impacts of low-income houses (Hashemi et al. 2015). However, the gradual replacement of sustainable locally available construction methods and materials, such as adobe, mud and poles (wattle and daub) and thatched roofs with environmentally harmful and low thermally resistant materials such as concrete and iron sheet roofs may not only increase the embodied energy but also deteriorate thermal comfort conditions in low-income housing sector. This situation in addition to imminent thermal discomfort caused by the global warming as well as defective design, inappropriate construction methods and poor workmanship may considerably affect the health and wellbeing of low-income people. To this end, this paper intends to assess the effects of various construction methods and materials on the risk and the extent of thermal discomfort in low-income naturally ventilated tropical housing in Uganda. 2. Housing types, conditions and construction methods Detached houses are the most common housing type in Uganda (58%) followed by huts (21.5%) and tenements (18.4%) (Table 1). According to the national surveys in 2002, 27% for Ugandan families lived in “room/rooms” dwelling types. This figure was 62% in urban and 21% in rural areas of the country (UBOS 2006). In 2005/06, over 50% of Ugandan families lived in single-roomed houses (NPA 2010). 614 ZEMCH 2015 | International Conference | Bari - Lecce, Italy