Existing formal low-cost houses in South Africa have been shown to be very thermally and energy inefficient. This could be problematic for the country since the government has promised to build roughly 3 million more of these houses in the near future. Inefficiency in these houses can be effectively addressed by installing ceilings, but the cost thereof is unfortunately too high to be affordable to the applicable sector of the population. New options need to be considered to reduce costs. Research has shown that practically any material can be used as a ceiling if it provides a barrier to heat flow and eliminates infiltration. The material should ideally possess good thermal properties and comply with standard building regulations, but most importantly, it must be very cheap and easy to install. The low-cost ceiling proposed in this paper has all of these attributes, and installation thereof could result in substantial energy savings, improved indoor comfort, and a better quality of life