In 1994, South Africa implemented a development programme to rectify the shortage of housing in the country through building subsidised housing for the low-income bracket. The low-cost nature of these buildings exposes them to potential poor thermal performance and occupants often resort to problematic ways of maintaining comfort, such as burning fuels to stay warm. This study presents a thermal analysis of a typical Low-Income Housing (LIH) building across the six climate zones of South Africa using DesignBuilder software with the EnergyPlus solution engine. The thermal performance and comfort of a typical LIH building was investigated by means of the extended PMV thermal comfort model and makes use of the seven-point thermal sensation scale as well as the predicted percentage of dissatisfied (PPD) index. For a representative climate zone, the reference building exhibited an annual mean PPD value of 30.35% with winter months exhibiting higher values (e.g. June exhibited a mean PPD value of 45.76%). These values exceed the ASHRAE specified upper limit of 20% PPD and indicate that the building is thermally uncomfortable for large periods of time. The addition of an Isoboard ceiling, and a more comprehensive building insulation intervention were investigated and shown to offer measureable improvement in thermal comfort. The study highlights the need to reconsider the nature of subsidy housing, with a specific focus on thermal performance, in order to fully realise the social upliftment aims of the housing programme.