shiwari 枝割

Rafter interval system. A measuring method begun in the mid-13th century used to determine the proportions of a building's structural materials. The unit of measure was based on the sum of the height and width of one rafter said to equal *isshi 一枝. This measurement was used to determine the distance between rafter centers, the distance from the center of one pillar to the center of another, the depth of eave projection, outside measurements gaihō sunpō 外法寸法, the width of frog-leg struts *kaerumata 蟇股 and other building measurements. The oldest extant example of a building employing this system is the Rengeōin Hondō 蓮華王院本堂 (1267; also popularly known as the Sanjū sangendō 三十三間堂) in Kyoto.