It is clear that the Imanishi-ke Jutaku was built in 1650 because of a long and narrow board referred to as munafuda bearing the year when the framework was completed, name of the client and the other people concerned with the construction including the master carpenter written in ink as well as an inscription referred to as onigawara-mei that was carved on the onigawara (Japanese gargoyle roof tile) that are used to decorate the ends of the roof ridges.
今西家住宅は、棟札と呼ばれる上棟時の年号や施主名や大工棟梁を初めとする施工関係者の名を墨書きした細長い板や、屋根の棟の端部を飾る鬼瓦に刻まれた鬼瓦銘と呼ぶ刻銘によって慶安3年の建立年代が明らかである。