constructive wood protection! The facade must be properly ventilated - avoid waterlogging. Everything there is in terms of coatings either doesn't bring much (transparent UV protection), washes off to varying degrees (staining), peels off, is toxic and/or has to be renewed every few years. If you don't want the Swedish red and don't want to paint the facade every few years, I would leave it natural. The transparent UV protection that lasts 20 years and makes your wood look like new does not exist. Whoever paints once, paints forever - so don't even start that. Tip: In the Alpine foothills, larch is usually used for this instead of spruce, at least for residential houses.