This is a single-family house equipped with an OM solar system. A large shelf is placed in the center of the house, where the stairs that ascend to the second floor are located. When climbing the stairs, the magnificent scenery of Mt. Asama and the sky meet the eyes; when descending the stairs, the soil and vegetable garden are all that can be discerned. In this way, the central staircase is connected directly to nature. Our aim was to create the sense of an “open” house by reversing the notions of indoors and outdoors through spatial cognition.