Kitakyushu Central Library
1973 - 1974
Building Area: 3,612 sqmTotal Floor Area: 9,212 sqm
Official Web Site
In Kitakyushu Central Library, the barrel vault was isolated and developed as the building's primary tectonic elements. As the program entailed grouping together, as a whole, completely independent cultural facilities - the city's central library, historical museum and audiovisual center - on a single site, the integrating role of an architectural system capable of bringing forth the necessary unity was assumed by the barrel vault.
The complex consists of two vaults running parallel to one another for a short distance before one of the pair turns 90 degrees, continuing in its extruded path for a considerable distance before turning back on itself and retreating along its original track. The other vault remains straight expect for the truncated "hook" at the end. While the historical museum and library are housed one in each of the two vaults, the audiovisual library, sharing the library's continuous vault, occupies the truncated "hook" at the farthest tip. The floor of the section devoted to the library raises progressively in a step-like fashion, with a ramp running parallel. The approach and front plaza paralleling the natural slope of the site also rises in a series of broad and gentle steps. The resulting L-shaped configuration with the long side corresponding to the library's rear elevation facing a large park also offers, as a backward glance, the impressive sight of Kokura Castle.
Structural methods used to create the unique form of the barrel vaults include the manufacture of two precast concrete sections to be joined at the highest point of the arch, forming, in structural terms, a three-pin arch. Three different profiles were required to complete the bending and continuous vault, one for the straight runs and another two fan-shaped sections for the barrel vault's curved regions. In order to successfully link the arched segments, the roof line must remain absolutely level. The floor-to-ceiling height of the interior rooms is adjusted to various levels through cast- in-place concrete platforms. On the building interior, the precast ribs are left exposed producing a rhythmic articulation of the vaulted ceiling. The vault is sheathed with copper sheet on its exterior surface.
While the function of the library museum is to reflect and explain the cultural history of the region by exhibiting the remains of ancient dwellings and artifacts, the pattern of the stained glass rose window illuminating one end adds a philosophical dimension. Color enlives the cosmological diagram as conceived by the highly original, locally born philosopher, Baien Miura and conveys a conception of the universe and of nature based on the oriental theory of Yin-Yang. By contrast the contours of the restaurant directly opposite describe a Marilyn Monroe curve, thereby releasing an element antagonistic to the regular curve of the vaults and the carefully regulated lines of the rose window.