Koshino House

Tadao Ando – koshino House, Ashiya, Hyogo Japan, 1980-1981

Tadao Ando’s design for Koshino House features two parallel rectangular concrete elements. The forms are partially buried in the sloping terrain of a national park and become a compositional addition to the landscape. Carefully positioned so as not to disturb the site’s existing trees, the structure responds to the adjacent ecosystem while the concrete forms address the larger nature through a playful manipulation of light. 
The northern volume consists of a two-story height containing a double-height living room, kitchen and dining room on the first floor with the master bedroom and study on the second floor. The southern container consists of six linearly organized children's rooms, a bathroom and a hall. The connection of the two spaces is a sub-level tunnel that is located under the external stairs of the courtyard.
Ando used the space within the two rectangular prisms to express the fundamental nature of the site. This space reveals a courtyard that covers and contours the natural topography.
A large series of stairs follows the sloping terrain into the enclosed outdoor space, light penetrates through the treetops into the courtyard. This autonomous space represents nature that has been delimited by the architectural structure and becomes artificial.
Narrow openings have been punched through the facades adjacent to the external staircase and manipulate complex passages of natural light and shadow into the interior spaces. The patterns provide the only amount of ornamentation to the simple rooms. Additional slots are cut from various planes of the two modules to produce the same effect of complexity throughout the house.
Four years after the original construction, Ando designed a new addition to the composition. Positioned to the north of the existing structures, the new cave-like space rests within the upwardly sloping piece of land. The study features a bold curve that contradicts the rectilinear organization, initiating a completely new rhythm.
Separated from the original courtyard design, the space between the addition and the original mass allows nature to remove the forms from each other. A patch of grass weaves between the concrete structures, while the curved wall extends from the building to define the outdoor space. Similar to the other boxes, a slice of the ceiling plane along the curved wall is removed to add a little complexity and ornamentation to the interior; however, the curved patterns of light differ significantly from the linear ones in the former building.