EFFECTS OF CLIMATIC FACTORS ON THE ORIENTATION OF KUDO-ZUKURI HOUSES IN NORTHWEST AREA ALONG ARIAKE SEA

Abstract

Kudo-zukuri is a vernacular house the roof of which is U-shaped in plan. The purpose of this study is to investigate what is behind the fact that the roof gaps of most kudo-zukuri houses in Kashima and Shiroishi of Saga prefecture face north-northeast. The wind roses derived from AMeDAS(Automated Meteorological Data Acquisition System) and AEROS(Atmospheric Environmental Regional Observation System) data show the prevailing winds come from northwest in winter and west-southwest in summer, and the northeast wind rarely blows. According to the survey materials with regard to the vernacular wind names by Sekiguchi(1985), the residents in Kashima recognize that west, northwest and south winds are strong or chilly. Thus for enduring the winds, the most appropriate direction of the roof gap is northeast. The mean depth of direct sunlight area into each main room at twenty-two kudo-zukuri houses, however, is longest in winter and zero in summer when the roof gap faces due north. When the gap faces the actual north-northeast direction, the depth in winter is shorter all morning, but is kept at 1.4 meters and above. In the cases of the northeast and east, the depths are much shorter in winter and the direct sunlight enters the room in summer. Consequently, the kudo-zukuri houses have good balance between wind enduring performance and sunlighting control due to their proper direction.