We make use of almost all types of wood approved for window construction. Our standard repertoire consists of pine, spruce, Siberian larch, oak and sipo mahogany. Softer woods such as spruce or pine are known for their excellent insulating qualities (U-values), whereas harder woods such as Siberian larch or oak are known for their durability. You can find a detailed description of the respective U-values for the various wood species listed under „profiles“.