Abstract The renovation of existing buildings represents a major challenge towards the transition to sustainable cities, as these edifices were built according to principles far from the current standards, especially in those urban areas where the poor quality of structures often determines social conditions of hardship and unlivable spaces. For refurbishment planning, suitable tools are required for the choice of more recommended interventions. For this purpose, the cost-optimal analysis represents a reliable way to promote the energy requalification of the existing building stock, identifying the best compromise between the energy demand reduction and the cost of the intervention. In this paper, a cost-optimal analysis was conducted on a reference building (RB) representative of a typical Italian social housing building, widespread in disadvantaged areas, strongly energy-inefficient and requiring urgent renovation. The influence of different energy efficient measures (EEMs) was considered by locating the RB in two different climatic zones, to evaluate how weather data also influence the obtained results. The economic analysis was carried out as a financial projection rather than a macroeconomic evaluation, in order to increase the stakeholder awareness for targeted routes addressed to the achievement of social and environmental advantages, while respecting a sustainable economic frame.