An eight-page building simulation explaining the aim of the European SSHORT (Sustainable Social Housing Refurbishment Technologies) project, which is to increase and promote rational and efficient use of energy in the retrofitting of social housing buildings. In this scope, one step was to develop a specific multi-criteria decision-making tool to support decisionmakers in choosing the most adequate energy technological solutions for refurbishment in Europe. The tool (System Selection Tool) is based on a method for multi-criteria evaluation of combinatorial systems. The tool aims at an energy system as a combination of technical solutions. Different possible technical solutions are positioned in an output and compared with existing configuration of the project according to a multi-criteria profile. This paper will present the methodology, the structure, the assessment and setting preference methods included in the tool. Refers to specific software tools that may not be available.