In this presentation, I will build upon a recent publication to propose a brief account on how to think more just energy transitions by complementing the capability theory with input from Cornelius Castoriadis, a Greek-French thinker (1922-1997). To this end, an analytical and quantifiable framework on energy justice and capability is first proposed to study most of the ten capabilities defined by Nussbaum (2000), by examining them for all households of a single country (Belgium) in relation to household access to affordable warmth. Results show that energy poverty in Belgium is statistically significantly 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. To fight these inequalities in our era of climate change, energy-justice policy should not aim at equalising energy consumption across all households but should rather equalise capability deployment.