The standard urban economics model of Alonso, Muth, Mills, describes analytically an equilibrium location of households in urban areas. We present an agent-based model, using simple interactions between agents, and able to reach this equilibrium in a dynamic way. The agent-based model allows us to simulate the development of a city by combination of heterogeneous agents and the introduction of several work centers. This tool allows the addition of a wide variety of features to the standard urban economics model to study their effects. We focus here on the study of the polycentric city.