The structure commonly had size of hashirama (bay, space or distance between two pillars) of 1 ken (unit of distance between two pillars) x 2 ken, and some had different variations such as 1 ken x 1 ken or 1 ken x 3 ken.
主な形態のものは柱間が1間×2間の規模のもので、これに1間×1間、1間×3間などのバリエーションが加わる。