Irimoya-zukuri

What irimoya-zukuri means

Irimoya-zukuri is a roof form that is gabled in its upper part and hipped in its lower part. Two slopes fall from the ridge, and beneath them a further set of slopes wraps around all four sides of the building.

Seen from the end of the building, a triangular gable appears near the top of the roof, with the eaves running horizontally below it. In Kirizuma-zukuri the triangle continues all the way down to the eaves; in Yosemune-zukuri no triangle appears at all. This form stacks one over the other.

In the structure field of the National Cultural Properties Database the roof shape and the roofing material are written in sequence. The main hall of Hazu Shrine in Aichi Prefecture is recorded as a single-bay shrine, irimoya-zukuri, entered from the gable end, with a front canopy and a Hiwadabuki roof. The gate of Sakurai Shrine in Fukuoka Prefecture is recorded as a three-bay gate, irimoya-zukuri, with a copper-sheet roof.

At Higashi Honganji in Kyoto one building is recorded with a floor area of 353.56 square metres, a single roof tier, irimoya-zukuri, and Sangawara-buki. The reference to a single tier distinguishes it from buildings with a pent skirt roof or with two full storeys of roofing.

Recognising it on site

Stand at the end of the building, where the ridge points towards you. If a triangular wall surface sits near the top of the roof with eaves running level beneath it, the roof is irimoya-zukuri. If the triangle reaches down to the eaves the roof is gabled, and if there is no triangle at all it is hipped.

Temples and shrines use the form for main halls, gates and reception buildings, and it appears on larger farmhouses as well. Storehouses and small ancillary buildings are more often gabled, since every additional slope makes the junctions harder to build and more expensive to maintain.

Shape and material are separate pieces of information in the record. The same roof form appears with cypress bark, with pantiles and with copper sheet, so a phrase such as irimoya-zukuri with a copper roof should be read as two facts rather than one compound term.