What the GIS community calls ``building topology'' is to establish the ordering information for a planar subdivision-determining the edges (arcs) around faces (polygons) and vertices (nodes). This task is complicated by the fact that the input data may be huge, imprecise, and occasionally erroneous; it is usually seen as an expensive batch computation process. Gold [57] has further advocating Voronoi diagrams as way of maintaining topology as a map is constructed. Because of the increase in data and computational effort, this will work best with smaller maps. What is the best way to combine these ideas with tiling ideas to operate on large amounts of data?