Whereas in the pre-industrial times the physiognomy of occidental towns was characterized by high persistence, there had been more degrees of freedom between radical transformation and adjoining regulation in the further development of urban cores. In a heuristic manner the model of a cycle theory has been tested for a change of paradigm since the beginning of industrial times. The fundamental result is the identification of almost two synchronic cycles, which started with a period of overcoming and changed into a period of acquisition. In analogy of both cycles the idea arises whether a change to a third cycle will gradually take place, nowadays.