This article raises the question of how to develop student engagement in activities for sustainable development in schools. It presents a case study in France resulting from a collaborative research involving the authors of this paper and a design team composed of two coordinators and two teachers, from elementary school and from the beginning of the college respectively. The project, designed by the teaching team, was carried out in two classes. Students had to design a new living space, one that remained fictitious, but which involved radically transforming their territory in order to make it pleasant and sustainable. After having imagined this new neighborhood, then transformed it by introducing constraints (related to energy, transportation, food, leisure…) and asking themselves questions, they then met, during a forum, experts in their area. The final stage of this process was a role-play during which the students were invited to take on the role of these experts and develop arguments about the construction of an amusement park in their neighborhood. From a scientific point of view, this article analyses the different levers mobilized by the design team to promote students' engagement and the importance of the creative character of the project.