Masonite (light beam) is great for building. Several advantages due to low weight = easy to handle, long spans in flooring (similar load-bearing capacity as glued laminated timber), dimensionally stable, can be precisely cut and bevel-cut, fewer thermal bridges. They are built with 8 mm construction board and withstand weather and wind well.
Hmmm, custom-made 45*225*12210 
http://www.familjenlindstrom.se/images/byggahus/stomme/bjalklag_smal_1.jpg
http://www.familjenlindstrom.se/images/byggahus/stomme/bjalklag_smal_1.jpg