The human building activity begins with the need to secure a living territory. If the outside of a building is a space for movement, the inside is for settlement. The architecture is not a concept separate from nature; it is integrated as one with nature.

Unlike in the past, where the objects present within the space were objectively recognized, the phenomenalistic view that they must be subjectively recognized is gaining weight. Thus, a continuity emerges across spatial boundaries, based on the belief that internal and external spaces are not mutually contradictory, but are the reaction to the same action. The method of implementing such a fluid concept of space was found in "Klein's bottle." The spatial flow and visual transparency render the separation between outside and inside space meaningless, creating a mutually flexible overlapping space that transcends the dichotomy of the two spaces.

All occurrences on the surface of Klein's bottle, where there are no boundaries between dimensions, flow through one surface. The outer and inner spaces, defined as contradictory (natural vs. artificial) in the modern era, have been virtually integrated applying IT technology on the surface. Seamlessly combining spaces of different nature (settlement vs. movement) it plays on the contradiction of the outside and inside existing together, and gives rise to another seeming contradiction, that there is no boundary separating between the two.

With the surface flow, people can overcome the concept of outside vs. inside, and feel the outside from the inside and display inside behavior at the outside. Perhaps what we believe as an "inside" or as an "outside" is a space that defies any such definition.