In the last ten years, the development and implementation of measures to mitigate climate change have become of major importance. In Europe, the residential sector accounts for 27% of the final energy consumption [1], and therefore contributes significantly to CO2 emissions. Roadmaps towards energy-efficient buildings have been proposed [2]. In such a context, the detailed characterization of residential building stocks in terms of age, type of construction, insulation level, energy vector, and of evolution prospects appears to be a useful contribution to the assessment of the impact of implementation of energy policies. In this work, a methodology to develop a tree-structure characterizing a residential building stock is presented in the frame of a bottom-up approach that aims to model and simulate domestic energy use. The methodology is applied to the Belgian case for the current situation and up to 2030 horizon. The potential applications of the developed tool are outlined.