If a flat has got two private cores (one on each end) the space in-between can be used by both of them. The closer you get to one core the more private it gets. The common space will be divided without walls.

In Japanese tradition the room is defined by its surface. That is why you will recognize the genkan's surface as the one of street although it is already located in the building’s volume. One step above the living space begins with wooden planks on the ground that is meant to mark that space.

In our project the room changes its character by the integration of steps. These can be used in many ways, for example as kitchen-board, so you can eat on that level as well.

The whole building is organized in steps. That makes the house into one room that has the shape of a spiral. Within this space there are private cores that spread into the semipublic spiral-room. By the use of light and easy moveable walls singular units can be separated. The spiral then will be disconnected temporarily but also a reorganization of the units related to a new living situation becomes possible. On demand the living space is able to extend or shrink.

The building is organized in a way that the spiral becomes more public down to its bottom. A shop on street level with minimal space can extend onto the street. Its appearance fits into the street image.