Text description provided by the architects. A house in Hyogo Prefecture, Japan. It is surrounded by a landscape of complex retaining walls and winding roads that have been created on a slope and are interwoven with lives. The site also contains a number of retaining walls of unknown origin and stairways that look like animal paths, giving the impression that this place is part of the transitional space of the city, and that in the past it was a place where roads intersected the retaining walls. From this situation, we wanted to think about the way in which a home should blend into and be connected to the flow of the city, using the streets of the past or present as a clue. We thought that by doing so, the house would be connected to the image of the city, and the perceived space would not be confined to the house but would expand into the city.
When we looked at the current road leading to the site, we found that it was a narrow road of about 2 meters in width that bent several times, making it impossible to transport building materials. Therefore, we started by considering a method that could be transported and assembled by hand. We focused on the arch as a form that can skip spans by combining small pieces. In the wood culture prone to earthquakes, we wondered if this shape could be assembled using wood and converting it to masonry.
We focused on LVL(Laminated Veneer Lumber) material that can be disassembled and assembled into small, light pieces, and came up with a mechanism that allows easy transportation and assembly by hand by assembling one arch with six 30 mm-thick LVL parts. The materials are cut from LVL boards using a laser, and the two pieces are stacked and connected by shifting their connecting positions so that they do not overlap, resulting in a relaxed arch structure made of small LVL units. This is a primitive system in which only compression and tension forces flow along the grain of the wood cut out along the fiber direction.
The wooden arches created in this way are held back to back and combined into a cruciform column shape, which is developed into a structure that stretches and repeats.
Next, the roofing of the structure was studied, and it was decided to make a series of vaulted roofs at 45 degrees diagonally from the grid of cruciform arches. By doing so, the coordinates of the cruciform columns and the diagonal vault overlap at the top and bottom, creating a multiaxial flow that responds to the flow of the surrounding spiral path, and at the same time, the openness of the house can be extended in multiple directions.
The form of the structure, which creates an expansive space through the assembly of small components, becomes a multiaxial coordinate that connects the flow of the road, extends the space in the perception into the expanse of the city, and aims to create a home that blends into the landscape of stretchy slopes.