In this paper, we shall be dealing with the problem of space layout planning. We present an approach based on an intermediate topological level with a dynamic space ordering (dso) heuristic. Our software ARCHiPLAN proceeds through a number of steps. First all the topologically different solutions, without presuming any precise dimension, are enumerated. Next, we may evolve in this topological solution space, and than refine some of them to form consistent geometrical solutions. For each topological solution chosen, the optimising geometrical solution is determined from a cost, useful surface or wall length. By using a dynamic space ordering heuristic in the topological level the enumeration time has been reduced.