The children’s urban council of Metz (Culture and Heritage Commission) has designed a model of its dream city of the future. In their vision, this city is green, sustainable and solidary. This model comes with a leaflet which transcribes the children’s words during its design, as well as the sketches that were made for this purpose. All the constructions were primarily made of recycled materials (paper, cardboard), and the leaflet’s texts were written based on the transcription of the children’s audio recordings. The model has been exhibited on several occasions, at the Metz Pompidou Centre or during the Ecology Festival organised by the European Institute for Ecology, as well as during the 2017 Heritage Days, where it proved very successful. The special feature of this eco-action was the consultation of inhabitants within the project, which led to the release of a document: “the 300 proposals of Metz residents in terms of sustainable development”. Let’s hope that these models will be a source of inspiration to build the city of tomorrow!