In this paper a novel technique is presented for representing a building façade's visual appearance in a large virtual urban environment. A fully automatic modelling system is utilised, capable of generating both the terrain and buildings for a 500m x 500m urban environment composed of over 120 K triangles. Applying the procedural texture generation approach permits the realisation of a large variation in the building façade's appearance, whilst remaining within the time constraints of an interactive simulation. The approach is efficient in terms of its memory usage and exploits the recent advances in graphics hardware. By procedurally generating the wall textures, the technique opens the possibility for interaction between various elements of a virtual environment, such as its inhabitants. This is evident in the rendering engine developed, which brings reflections of both the static geometry and the dynamic virtual humans for all window panes into the real-time domain. Height and navigation maps are automatically created, allowing the virtual humans to be automatically populated within the scene. From a dynamic human model cached animations and static billboard impostors are created efficiently on load, allowing for complete model flexibility.