This chapter explores the energy justice nexus, drawing on Sen and Nussbaum’s concept of capabilities. Our contribution operationalises most of the ten capabilities defined by Nussbaum (2000), and examines them for all households of Belgium in relation to household access to energy and especially to affordable warmth. We argue that inequities regarding access to affordable warmth are more evident when posed contra the range of differences between energy-poor households and other types of households of a country. Thus, we propose a five-group typology of households that also takes into account the social aid granted in the country. This typology is used to compare across these five groups the extent to which energy poverty is associated with other difficulties of daily life beyond just housing and health. A new simple statistical index is developed to summarise these comparisons. The approach of the energy justice nexus is thus systemic rather than causal between access to energy and potential capabilities’ deprivation. The data used is a large-scale quantitative survey that is part of the Generation and Gender Programme (GGP), and it enables to proxy most of Nussbaum’s capabilities with several questions asked in this GGP survey. As these GGP surveys are standardised and realised in 16 countries, our approach is transferable to other nations/regions as well. Results show that energy poverty in Belgium is associated with deprivation of several capabilities, in more areas than expected: not only regarding housing, health, and mobility, but also regarding access to culture and recreational activities, as well as the feeling of fulfilment and ontological security. A special interest is dedicated to gender and generational aspects of energy poverty in Belgium.