The purpose of this paper is to present a new modelling approach which deals with the spatial spreading of built-up areas, on a local or regional scale. Our spatial modelling is similar to cellular automata but differs in the use of image processing method and mathematical morphology algorithms. In this model, the spatial spread process depends on both proximity and morphology of the built-up areas located in a space whose configuration also determines the shape of the spatial spread. These features explain the “spatio morphological” qualifier given to this model. This paper firstly presents the spatio-morphological modelling approach and the steps used to simulate the spatial extension of built-up areas. Secondly, this model is applied to the coast of Languedoc in a Southern region of France subjected to a strong residential pressure.