What are houses made out of in Greenland?

Answer 1

Rocks, sod, flotsam. Not trees, there aren't any.

Answer 2

Houses in Greenland are typically made out of a combination of traditional materials such as sod, stone, and wood. The walls are often insulated with thick layers of turf or sod, which provide excellent insulation against the cold climate. Modern houses also incorporate contemporary building materials like concrete and metal in their construction.