Most of them are made by a method called 'hanchiku' in which columns are built on a stone wall foundation and a frame with rails is built and then encased in a wooden frame and mud is poured in and rammed with a stick.
石垣の基礎に柱を立てて貫(建築)を通した骨組みを木枠で挟み、そこに練り土を入れて棒でつき固める「版築」という方法で作られる物が多い。