The CSIR Housing Research Group in collaboration with a number of partners has been investigating the concepts of sustainable building transformation in the South African housing sector. These studies have relied heavily on a number of theories, including Habraken’s Supports, Open Building levels as well as concepts of material/component re-use. All of these theories provide approaches with regards to the way in which materials, building components and the buildings themselves are re-used or salvaged, based on life cycle analysis. There are numerous terms used to describe this approach to the design of the built environment and these are sometimes confusingly interchanged. Thus, this paper presents descriptions of concepts and working definitions and then proceeds to carry this investigation further by analysing housing case studies with regards to sustainable building transformation. In this process it is attempted to assess if the approaches are relevant and applicable in the South African context. While it is acknowledged that these approaches to design and delivery need to be considered for the whole housing market, there is a pressing challenge to government to deliver low-cost and affordable housing. We also saw an assessment tool for existing buildings as an important way to try and influence thinking, design and planned delivery approaches at the conceptual stages, before future projects proceed in the typical manner which we perceive to be unsustainable. The capacity for sustainable building transformation will be rationally assessed by studying the internal planning, construction methods and material selection of the selected projects. The paper presents a tool for assessment and comparison, studies the possible changes in the existing projects and also makes some basic recommendations for new projects.