Fro the company’s site:

The base of the Wikkelhouse is ‘virgin fiber paperboard’, which is made from Scandinavian trees. This so called goldboard, is wrapped around a huge mold, with a method patented by RS Developments, while environmentally friendly glue is added. This creates a tough and insulating sandwich structure. By this wrapping process a heat insulation and construction method are integrated in a sustainable way. Afterwards each segment is finished with a protective film and a shell of wooden slats.Wikkelhouse meets the criteria for temporary or permanent housing. It is about eight times more durable than traditional construction.