This research paper presents a project in environnemental education to sustainable development in elementary school. The project, initiated with children around ten years old, begins with the assumption that a project in education to sustainable development would allow children to enhance disciplinary skills but also gain moral and civic values (solidarity, mutual aid or cooperation) through a project oriented approach. This experimentation is based on research showing that citizen is a deeply involved actor in the protection of the environment. Applying this principle, my pupils have followed the scheme « Builders of possibilities » and decided together what problem they wanted to solve, the solutions to apply, the actions they wanted to implement and finally the sharing of experience. The results show that the project had positive effects on the atmosphere in the classroom. However, the implementation of a caring framework and cooperation within the classroom should be introduced at the very beginning of the school year.