In ancient times, the Vikings had two popular methods of building houses. In warmer climates, they would choose to construct all their buildings with wooden boards.
On the other hand, in colder areas, when building their residential rooms, the Vikings would first dig a shallow pit and pile up thick stone walls around the pit.
Following that, they would stake wooden piles on the inner side of the stone wall and build a wooden structure of the house, finally layering the outside of the wooden structure with a layer of grass turf mixed with mud for insulation.
As a result, due to the thick layer of mud and stones, the whole room would become much warmer than a room built entirely out of wood, preventing the cold wind from seeping into the house through gaps in the wooden boards.
The remnants of the walls that Leonard and others have excavated now look almost identical to the photos of wall ruins excavated from Northern Europe, strongly corroborating the builders of these structures.
