In this paper, we explore the route beyond the conventional, linear attitude within planning and its rationality debate. We combine our theoretical reasoning with a multiscale approach and with fractal-like argumentation which results in a frame of conditions which is supported by the outline of a theoretical conceptual simulation model which would also allow non-linear, iterative simulations of the urban space. The understanding of autonomous non-linear spatial development has a direct impact on planning. Addressing the underlying thinking behind Haken’s synergetics we develop a framework within which the interdependencies between different levels of scale are key. We are aware that bottom-up and top-down processes often have a mutual influence on one another. We therefore propose a conceptual simulation model for planning where conditions have an impact at various levels of scale. In coherence with the idea of the ‘dynamic behaviour of the system after a planning decision was made’, this feedback gives us information on the surviving and non-surviving planning scenarios and decisions and is reminiscent of systems which are open to self-organizing pattern formation. Our reasoning with regard to planning and decision-making and their multilevel consequences is strongly influenced by the arguments presented in complexity studies.