This article aims to contribute to the characterization of the city production in the beginning of the twenty-first century. For this purpose, we model urban project under construction as a mediation process between the representations of its designers and receptors (inhabitants). Our goal is to understand how they are formulated and how they influence each other in order to comprehend why they do not join. This dialectical approach emphasizes the multiplicity of meanings that can be given to material and symbolic properties of a territory. Through the analyze of the representations of the designers and inhabitants of the ecological neighborhood Bottière-Chénaie in Nantes, we will show the relationship between them and the need to go over the simplistic vision of the urban project as a linear process - design, realization, reception - and to incorporate models including the influences of effects on causes into the field of urban research.