This style originated in the Asuka (538-710) and Nara period (710-794), when Japanese studied Buddhist architecture of the Tang dynasty, and was improved in the Heian period (794-1185) to suit the Japanese climate and aesthetic sense.
After the Kamakura period, the Wayō developed into the Shin-wayō style by combining it with the Daibutsuyō, and further developed into the Setchūyō by combining it with the Zenshūyō, and pure Wayō architecture decreased.
[4] It was characterized by simplicity, refraining from ornamentation, use of natural timber and in general plain materials.
Structurally, it was distinguished by a main hall divided in two parts, an outer area for novices and an inner area for initiates, a hip-and-gable roof covering both areas, a raised wooden floor instead of the tile or stone floors of earlier temples, extended eaves to cover the front steps; shingles or bark rather than tile roofing; and a disposition of the shichidō garan adapting to the natural environment, rather than following the symmetrical layouts prevalent for example in Zen temples.
[5][6] During the Heian period temples were built using only non-penetrating tie beams (nageshi (長押)) made to fit around columns and pillars and nailed.