According to the United Nations’ medium-scenario projections, Africa’s population will rise to 2.5 billion in 2050 and to more than 4 billion in 2100, which is the fastest population growth rate in the world. This population growth in tropical Africa results in a large and unmet demand for appropriate housing, which contributes to insecurity, poor health, and migration. Nevertheless, sub-Saharan Africa is predicted to have the second fastest growing regional economy by 2020 , which would be an opportunity to invest in healthy house designs that help meet targets on disease and well-being. There is a notion that the rural population in Africa is stable or even shrinking due to urban migration.

The mud house, a basic wattle and daub construction with a thatched roof, is the most common housing type throughout rural Africa. While wattle and daub is increasingly replaced by burnt brick and concrete and thatched roofs are replaced with metal sheets, the overall house design, including the pounded earth floor, remains unchanged. Heavy, poorly ventilated single story buildings are the norm. The resultant design with its thick walls and heavy roofs provides a high thermal mass that can provide comfort in arid African climates, where temperatures are high during the day but drop at night. Heat is absorbed by the thick walls and floors during the day, then radiates into the house during cold nights. By early morning, the building has cooled down and trapped cool air, and cooled walls stabilize temperature as the outside temperature rises. Radically different building designs are needed for thermal comfort in hot-humid climate zones, typical of much of Africa ( blue zones).