The construction period of the ondol (Korean floor heating system) at Hoeamsa Temple Site is known as Joseon. The main reason is that a large number of remains in the Joseon era were excavated from the ondol floor with an all-around ondol method. This article partially accepts the theory of the creation of Ondol at Hoeamsa Temple Site during the Joseon Dynasty and suggests a new argument that some Ondol remains were built during the Goryeo Dynasty. The grounds for them are as follows. First, through the building sites consistent with the arrangement of the Cheonbosan Hoeamsa Sujogi (天寶山檜 巖寺修造記, Record of Repair and Construction of Hoeamsa at Cheonbosan Mountain), it is highly likely that the ondol remains as a basic floor was maintained during the reconstruction period in Goryeo. Second, the all-around ondol method of the Monastery Site has already been widely used since the Goryeo Dynasty. Third, some ondol remains consist of "Mingaejari" and "Dunbeonggaejari," which were the methods of the gaejari (which dug deeper and stayed in the smoke) in the pre-Joseon Dynasty. Based on the above evidence, this study argues that the building sites such as Dongbangjangji, Seobangjangji, Ipsilyoji, Sijaeyoji, Susewaryoji, Seogiyoji, Seoseungdangji, Jijangryoji, and Hyanghwaryoji were constructed during the late Goryeo Dynasty.