A paradigm shift is evident in recent research on comfort, energy efficiency, and building sustainability. Initially, studies relied on population-based data, which constituted static prediction models such as the PMV model and dynamic models like the adaptive model to predict comfort for a population. However, new personalised models are emerging, based on individuals or small groups with similarities, such as the cohort comfort models, or entirely personalised comfort model. These developments are likely to be the focal points of research and development in the coming decade. This study shows an example of how comfort retention can be analysed to see the sustainability of decisions in buildings.