In order to enable designers to envision the behaviour of pedestrians with reference to specific environments, computational models of crowds and their movement become indispensable tools of evaluation as well as tools of creativity. In this paper, the model under development constitutes a generic model which incorporates ideas about agent-based systems. The simulation program comprises a support system for the designer to place virtual users in a context that bears analogous environmental traits of the area under study. The design problem which is addressed by the implementation deals with public squares for which the programmatic demands involve a broad spectrum of users of diverse idiosyncrasies. Our study attempts to elucidate how the variation in preferences of pedestrian movement which depend on various personal, situational and environmental factors, may influence the current use of a selected public space and underpin qualitative alterations compared to its initial design. The intent of the methodology is not to create a predictive tool of naturalistic human movement but to explore how spatial configuration can be assessed and developed through a simulation model of pedestrian behaviour.