It has been archaeologically proved that the roofs of the palaces such as Daigokuden (Council Hall in the Imperial Palace) were covered with Kawara tiles in the Fujiwara Capital, which was constructed at the end of the 7th century, therefore it is believed that Kawara was first used for the buildings other than temples at that time.
7世紀末に建設された藤原京では、大極殿などの宮殿は瓦葺きで建てられていることが考古学的に確認されていることから、初めて寺院以外で瓦が使用されたとみられている。