Expression of Concrete Eaves in Public Buildings of Postwar Japan

Abstract

Introduction Background and Aim of StudyDeep projecting eaves as the skirt of a large roof, known from temples and shrines, are one of the most significant expressions in traditional Japanese architecture. 1) Initially serving as a device to protect the wooden structure from precipitation and light, Japanese carpentry developed sophisticated techniques to project and decorate eaves 2) incorporating representative purposes as well as environmental concerns. Hence, eaves have become a characteristic element that provides a reference to Japanese architectural tradition. According to the historian Siegfried Giedion, a monumental expression addresses an eternal need of the people who want their buildings to be representatives of their social, ceremonial, and communal life. 3) Against this backdrop, the architectural expression of eaves in the postwar period gains relevance. With the Treaty of San Francisco, which came into force in 1952, Japan's rapid modernization took command. The imposed new democratization caused a widespread reconstruction of residential, cultural and political facilities. 4) Especially public buildings, such as government buildings and city halls, which had been destroyed in the war and needed to be reconstructed, and emerging building programs and types, such as congress and concert halls, were implemented and required an appropriate architectural expression. Responding to the new modernization, Japanese architects attempted to continue tradition in their design practices. Known as dento ronso, the debate on tradition focusing on aesthetic and historical identity in architectural expression flourished in postwar Japan. At this critical point, the expression of a large, monumental roof seemed to be adequate neither from a symbolic viewpoint nor considering the manifestations of modern architecture and nearly disappeared in public buildings. On the other hand, the deep projecting eaves extending the horizontal line of a flat roof became the traditional expression applicable for public buildings (Fig. 1).At the same time, reinforced concrete became the predominant material for public buildings in Japan. Then, horizontal eaves and concrete construction were both demanded in public buildings.When the rest of the world was taken up the possibilities of lightness offered by concrete -especially shell structures -Japanese architects went the opposite direction towards weight and solidity. 5) This contradiction that eaves were executed of a material that opposes the idea of a cantilever challenging gravity resulted in a ＊1 ＊2