However, research at the time of demolition for repair shows that it was a reconstruction of the former hall built in the beginning of the Heian period (about the ninth century) and that a part of material of the building in the Nara period was also diverted.
が、解体修理寺の調査の結果から、平安時代初期（9世紀頃）に建てられた前身堂を改築したものであり、さらにさかのぼる奈良時代の建物の部材も一部転用されていることがわかっている。