Living Labs (LL) are complex multi-stakeholders ecosystems of innovation. When co-creating a service, each actor has his own strategic agenda. Finding a common ground for co-creating a service is not an easy task and requires tools to facilitate and structure the reflection. This paper examines how “service blueprinting” techniques can contribute to improve the co-creation process in a living lab setting and develop a common ground. To our knowledge, this service development method has never been tested in a living lab process and no integrative analysis of this case has been conducted so far. The aim of this paper is to test this tool, thus creating bridges between service design (SD) science and Living Labs. To test this process, a first generic blueprint of the existing service has been designed, before organising a multi-stakeholder focus group, based on the Quadruple Helix Model, in order to develop the new service. The context of the case study is to develop a service to facilitate the energy transition but it could be tested in different sectors as well. The main findings are that the combination of these two approaches (LL and SD), launches the dialogue, contributes to set a common vision in a multi-stakeholders' ecosystem and forces the participants to integrate implementation constraints right from the beginning of the co-creation process. Even though Living Lab approaches are employed rather upstream of the innovation process and blueprinting methods more down-stream, top-down planning and bottom-up participation could be complementary when combined.