Kansai-Khan National Library
Tokyo, Japan

The design concept for the Kansai-Khan National Library uses paper as
the model for the development of its structure. A single sheet of paper is fragile and free-flowing, but together sheets of paper gather strength and form a book. Planes of lightweight steel sheets form the roof of the library, a structure that allows light to penetrate into the reading areas on the main floor, yet provides protection from the environment. The books are stored below the main level in four separate stacks made of reinforced concrete to carry the heavy load. The concept is to store the numerous volumes of information in a safe environment much like pages stored in a book when it is closed. Yet when the volumes are brought to the main level and read it is much like opening a book.

The stack system is built completely underground with reinforced concrete to increase the resistance to seismic forces. Placing the building's center of gravity below ground level allows the building to have an up righting capability during lateral movement of the earth. Above the base of the stack structure the materials change to lightweight glass and steel. The roof covers the entire structure in a single curved plane and consists of three layers of steel sheets connected by rows of tetrahedrons. This creates a sandwiched plane of incredible strength, stable in all directions. Water is directed away from the building through a perimeter drainage system and the concrete
exterior walls are waterproofed to prevent water infiltration into the stacks. Each floor is isolated to prevent the spread of fire. The core towers in the four corners of the building allow the basement levels to be safely evacuated, while additional exits provide for the evacuation of the most concentrated areas.

The mechanical systems developed are straightforward and efficient. Temperature and humidity below ground level provide ideal conditions for the storage of books, as they remain constant. Piping systems to the boilers and air-handling units travel vertically through the four cores in each corner of the building. A/C units are fed by a four-pipe system between the main chillers and the reflecting pool that acts as the condenser. The design concept places the mechanical rooms along the southern wall allowing for future expansion. The stacks can be
mirrored and reproduced on the southern side using the same footprint as the existing stacks. The expansion stack floors will be level with the current stacks, easing circulation between phases one and two.