An irimoya style roof is composed of a kirizuma-zukuri style roof in its upper part (which inclines backward and forward when viewed from the longer side of the roof) and a yosemune-zukuri style roof in the lower part (which inclines in each of the four sides of a rectangular house).
入母屋造の屋根は、上部においては切妻造（長辺側から見て前後二方向に勾配をもつ）、下部においては寄棟造（前後左右四方向へ勾配をもつ）となる構造をもつ。