The durability of wood regards the natural resistance of the heartwood against wood-destroying fungus and is defined according to EN 350-2 in Europe. The European larch is currently rated between Class 3 and 4. Experts from local companies define the local mountain larch from South Tyrol as very strong and durable. Equating it with the European larch, which mainly grows in lowlands (Germany and Czech Republic), is therefore unjustified. It is expected that EN 350-2 is amended in the coming years. Accordingly, timber of the durabilty classes three to five may only be used in the outdoor areas when treated with chemical wood preservatives in Germany. The aim of this project is the registration of the larch in the durability class two to three according to EN350-2.