High-efficiency insulation

[HBK]

Is there any type of insulation that can be used in housing instead of the traditional stone/glass wool & styrofoam? What I'm looking for is an insulation that is thinner but still insulates just as well. Since I am only looking for a few square meters, the price is of little importance. Anyone with knowledge?

 

[sthe]

Well, there are no wonders here, the best that is somewhat easy to get is polyurethane foam (PUR) insulation used mainly for refrigerator insulation. It often has a lambda value lower than 30. You can find it at refrigeration companies. Next best is extruded polystyrene (XPS), available in well-stocked building supply stores. Lambda down towards 30. Compared to mineral wool which has a lambda around 40.