1 The direction of the purlins or plates *keta 桁 in a building, often at right angles to the main transverse beams *hari 梁 and parallel to the roof ridge *mune 棟. A structural member that runs in the direction of the keta, ketayuki hōkō 桁行方向, thus longitudinally through a building is called a ketayuki hōkōdanmen 桁行方向断面. At times ketayuki may be used to refer to the direction of structural members irrespective of their direction relative to the roof.
2 The aggregate distance spanned by the longitudinal purlins or plates of the main frame *jōyageta 上屋桁, as measured from the center line of the support posts *hashira 柱 or struts *tsuka 束 at either end. The figure may be expressed as a metric measure, Japanese feet, shaku 尺 or bays *ken 間. If a building has pent roofs or aisles *hisashi 廂, *geya 下屋 at one or both ends, the ketayuki is less than the overall length of the building.
3 The overall length of a building (measured either in metric in bays), irrespective of the aggregate span of the main longitudinal purlins or plates.