The roof of Sesseljuhus is clad with a new, environmentally friendly roofing fabric from the Norwegian company Protan. The bulk of the roof is insulated on the outside, with compressed wool applied directly onto the fabric. On top of the wool is laid a layer of turf, which also adds to the insulation value. This is actually a traditional roofing method and insulation material. What was unusual, in terms of insulation, was the use also of recycled paper, free of irritants or fibrous materials.
Icelandic rock wool is the only kind in the world produced without combustion of coal. Furthermore, raw materials for the Rock Wool Factory Center are found on the beach and in the sea, but returned immediately after use to maintain the sand. Therefore, there is no visual pollution resulting from the processing of raw materials after 18 years of operations, unlike many other places.