The architect that is given the opportunity to design urban space, needs to take into account as much data as possible as well as his own unawareness. To do so, he needs the proper tools to handle the city complexity and when necessary, to control his lack of understanding. Modern theory of complexity developed in the region of hard physical or mathematical science can be used for a new fruitful extension of the architectural theory.For an architect, an urban designer, the final goal should always be the production of livable and vivid space within the city; Space that will satisfy the citizens' needs and reflect his own ideas expressed through his work, at the same time. While he tries to "decode" and understand urban space, conjectures are made by him, so as to create a simplified "image", a model representing in an abstract way a chaotic reality of infinite factors. His ideas, based on these "artificial" realities, represent an abstract approach to a desired goal. This procedure, even though seems the most logical or "sincere" approach, it always contains the risk of failure in the very primary conjectures made for the urban space. Concerning the urban dynamics the modern architect must be aware of their internal uncertainty of the urban dynamics produced by their non-linear character in accordance with the deterministic chaos included in nonlinear systems. An architect who seeks to reconnect his ideas, his personal theories, his beliefs with reality, while not becoming a mere facilitator of a fashion-style architectural approach at best, has to operate in the borderline between the two extremes. Moreover, establishing scale between them becomes crucial. Thus he will reach the golden ratio in the process of the production of space, choropoetics, and create high-quality urban space. Seeking the theoretical background that will answer how such a procedure could become possible, the theory of Complexity might be the proper tool that will define whether architecture is to be seen as an individual act, or an act of collective responsibility and involvement in which complex and infinite factors counteract dynamically.