What ketayuki means
Ketayuki is the direction parallel to the ridge of a building, or the length of the building measured in that direction. The word comes from keta, the horizontal members that run along the building in line with the ridge, and it is paired with Harima, the direction at right angles to the ridge. The structure line of a designation record gives the two together, as three bays ketayuki by two bays harima, to state the size of the plan.
The distinction depends on the direction of the ridge, not on which side is longer. In most buildings the ridge runs along the longer side, so the ketayuki figure is the larger, but in a near-square building or one that runs deep from the front, the harima figure can equal or exceed it. The commentary on the main hall of Kamosu Shrine, for example, notes that the building is slightly longer in the ketayuki direction than across it and reads this as a sign of an old form.
Two units are used. The first is the number of bays between posts: three bays ketayuki means three intervals between posts along the ridge. The Ken here counts intervals and is not necessarily the length unit of about 1.8 metres that shares the name. The second is a measured length, and records for registered buildings often give figures such as 11 metres ketayuki by 4.0 metres harima.
Reading the records and the building
Start with the direction of the ridge. The record for a rice storehouse of the Iida family gives nine bays ketayuki, three bays harima and adds that the ridge runs north and south. Once the ridge direction is known, it is clear which faces are the ketayuki sides and the plan can be pictured on site. On a gabled building the bays counted along the eaves side, where the slope of the roof is visible, are the ketayuki bays.
Records for townhouses and storehouses sometimes use maguchi, the frontage on the street, and okuyuki, the depth back from it. These follow the street, not the ridge. In a townhouse entered from the gable end the frontage corresponds to harima, and in one entered from the eaves side it corresponds to ketayuki, so the ridge direction should be checked before one term is exchanged for the other in an article.
Shrine records sometimes count the bays of the front and the side instead. That is also a different system; in a shrine whose ridge runs parallel to its front, the bays of the front are the ketayuki bays.
References
- 飯田家住宅米蔵｜国指定文化財等データベース（文化庁）
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00005174
- 神魂神社本殿｜文化遺産オンライン
- https://online.bunka.go.jp/heritages/detail/146648
- 田中家住宅長屋門｜国指定文化財等データベース（文化庁）
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00007648
- 波多腰家住宅味噌蔵｜国指定文化財等データベース（文化庁）
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00001700
Last verified: 2026.09.26