En (architecture) - En

Japanese: 縁（建築） - えん

...The foundations of the Asuka and Nara periods were generally high, some of which were double-layered like the Golden Hall and five-story pagoda of Horyu-ji Temple, and some of which had a raised platform like the Yumedono Hall, but they gradually became lower and were usually single-layered. During the Heian period, when floorboards were laid inside Buddhist halls, a veranda was created around the perimeter, and the foundation was hidden underneath, and a turtle-like base made of piled earth and painted with plaster was used (Figure 2). In the early modern period, the veranda disappeared, and it became common to place the foundation stones at ground level. ...

From [Japanese Architecture]

…In Japan, the Nara period architecture adopted the Tang Dynasty style as it was, but in the Heian and Kamakura periods, eaves gradually became deeper. This was to protect the walls and edges from rain, and was also necessary in hot seasons and when it was raining so that doors could be kept open. A floor was laid inside the building. …

*Some of the terminology explanations that mention "en (architecture)" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

Japanese:

…飛鳥･奈良時代の基壇は一般に高さが高く，なかには法隆寺の金堂，五重塔のように二重に築いたり，夢殿のように壇上に高(勾)欄を巡らしたものもあるが，しだいに低くなり，普通は一重である。平安時代に仏堂内部に床板を張るようになると，周囲に縁（えん）ができて，基壇はその下に隠れ，土を盛って周囲を漆喰（しつくい）などで塗った亀腹（かめばら）が用いられる(図2)。近世にはさらにこの亀腹もなくなり，地表面の高さに礎石をすえるのが一般的になる。…