Early Japanese houses were pit-dwellings or pit-houses. The foundations of which are routinely unearthed during large scale renovations or construction projects. The construction of ancient dwellings began with a mound of raised earth.
The floor, which varied from circular to rectangular, was dug out a foot and a half deep, upon which pillars that supported the rafters and beams used to construct the frame for thatching the roof were erected.
The exterior of the dwelling was surrounded in grass. Elevated wooden structures were also used to store grain and other provisions away from the heat and humidity. These elevated wooden structures, unlike pit-houses, are said to have their origins in Southeast Asia.
Pit-houses, thought to have been common beginning in the late stone age, and into the Jomon and Yayoi era were not the only housing structures. Humble huts and other walled buildings were also believed to be in use, however, the latter were largely reserved for leaders of local communities, as symbols of authority. It is those houses, researchers believe, that form the basis for the traditional Japanese house that we know today.
Yoshinogari Ancient Ruins Saga Prefecture 
The Toro remains in Suruga ward, Shizuoka 
Archaelogical work during WWII 
Ancient dwelling under a rice field 
Ancient Pit House reconstruction 
Ancient Pit House Frame 
Storehouse said to be of Southeast Asian origin 
Re-enactment
