To understand the complexity of modern cities and anticipate their expansion, experts from various fields conceive simulation models that can be very different. Those simulation models work with a variety of data with their own organization. Furthermore, because the urban objects are studied in the context of the evolution of a city or urban area, they carry temporal and spatial information. In this paper, we present the base classes of a common data model robust and flexible enough to serve the identified use cases. We then introduce a mechanism that allows to add thematic information to those classes. We also present some possibilities of the use of the data model. We end this paper by evoking the future improvements of the data model.