Yosemune-zukuri

What yosemune-zukuri means

Yosemune-zukuri is a Japanese roof form that slopes in four directions from the ridge, giving trapezoidal surfaces on the long sides and triangular ones on the short sides. English usage calls it a hipped roof.

No triangular gable wall rises at either end. The roof covers all four faces of the building instead. With no exposed gable, water runs off cleanly and wind passes over the whole form, which is much of the reason the shape recurs in farmhouses, storehouses, and in the offices and schools built during Japan's modern period.

The corners take work. A hip rafter has to receive the rafters from two directions at once and hold the eaves line level as it turns, so the framing is more involved than a gabled roof. The top is a single ridge with hip ridges running down from each end of it.

Put a gable on the upper half of a hipped roof and the result is irimoya-zukuri, the form Japanese temple and shrine architecture has long treated as the more formal of the two. Yosemune-zukuri stayed with houses and working buildings. Heritage records pair the shape with its covering, as in yosemune-zukuri teppanbuki, a hipped roof clad in sheet steel.

Telling it apart on site

Stand at a corner of the building. If the roof plane folds around that corner and carries on down both faces, the form is hipped. Walk to the short end: if no triangular wall appears beneath the eaves, you can settle on yosemune-zukuri.

Western-influenced buildings of the modern period often put sheet metal or tile on a hipped roof and keep the eaves shallow. A traditional thatched farmhouse under the same roof form swells into something quite different in outline. The shape is one thing; the covering and the depth of the eaves decide how it reads.