Located in the Hyogo Prefecture of Japan, House in Koyoen by Tomohiro Hata Architect and Associates is surrounded by a landscape of complex retaining walls and winding roads. The building’s orientation and structural concept take the best advantage of this context by displaying a perception of expanded space that extends into the city.
The location’s narrow access road of 2 meters made it nearly impossible to transport building materials to the site. The architects thus began by considering construction methods that could be transported and assembled by hand. They ultimately focused on the arch as an efficient form, working with LVL (Laminated Veneer Lumber ) materials that can be disassembled and assembled into small, light pieces. A mechanism was developed allowing for easy transportation and assembly by hand with one arch comprising six 20mm-thick LVL parts.
The parts are cut from LVL boards using a laser with two pieces stacked and connected by shifting their connecting positions so that they do not overlap. The result is an arch structure of small LVL units. It is a simple system in which only compression and tension forces flow along the grain of the wood and the fibre direction.
The wooden arches are held back to back and combined into a cruciform column shape, which is then developed into a repeating structure.
It was decided to make a series of vaulted roofs at a 45 degree diagonally from the grid of cruciform arches. The result is a multiaxial flow that responds to the flow of the surrounding paths, and at the same time opens the interior space up in multiple directions.
