In the EU, buildings consume 40% of the final energy and are responsible for one- third of the CO2 emissions. Since new buildings account just for 1% of the stock, the largest opportunity to implement energy efficiency comes from the renovation of existing buildings. However, renovation projects address particularities that make the selection of suitable options a complex process. Developing tools to support this process requires to get a better understanding of who participates, what criteria stakeholders consider, how they assess alternatives, and what methods they implement. Therefore, this paper studies how the decision-making process was performed in two residential case studies: An apartment building in Spain, and a set of dwellings in The Netherlands. The main goal is to identify stakeholders, objectives, criteria, alternatives assessment methods, and the sequence of the decision-making process. Findings are contrasted with concepts presented in the related literature. Results show that not only energy-related activities are considered in the decision- making process, but also additional renovation tasks that are performed simultaneously. Social criteria play an important role in the process. Moreover, renovation deals with stakeholders' interactions related not only to the landlord/tenant dilemma, which may impact the process and final solution.