Dense, well-insulated wooden house without plastic? (Vapor barrier)

Hello Alex,
yes, you are right that the foil doesn't make a huge difference now. It mostly gets installed once and then stays in the house for decades.
That raises the next question. How long is the lifespan of such a foil? Does it have to be replaced every X years? That wouldn't be so good either.

I just find it a bit unappealing, which is why I want to find out if it can be done without it. And if yes, how?

Regards
Specki

You are right about the leakiness; especially when building with wood, this is one of the main disadvantages

According to our energy consultant who performed the blower door test, airtightness is almost unattainable in well-constructed timber frame buildings compared to solid houses.

More and more suppliers are presumably moving away from the sheet, especially regional carpentry companies. In our case, the OSB board is also sealed airtight and thus serves as the vapor barrier. However, the OSB board also contains adhesive, which again does not quite fit with eco-friendliness. But completely eco was personally too much for me; I think one has to find a compromise. We also have a timber frame house, which is blown with wood fiber. On the outside, wood fiber insulation boards and in the installation level also wood fiber insulation. But even the wood fiber insulation is not pure wood, but treated. So also not 100% eco in my opinion. And the solid wood ceiling is glued.

Because on the one hand I would like to avoid plastic as much as possible.

Depending on the requirements, OSB boards are not uncritical either. Would a solid brick construction be an option? In my opinion, its wall structure can also be "without plastic" if mortar is used (no adhesive).

But mostly because it is always a potential problem area.

As far as I know, a separate pre-wall as an installation level practically solves all problem areas here.

I don't find solid wood so good, I was rather thinking of a timber frame construction with insulation.

Solid was just my first silly thought. If you look at the mentioned provider, you will see that they also build multilayered and insulated there. Instead of OSB, they use gypsum boards.

According to our energy consultant who conducted the blower door test, the airtightness in well-crafted timber frame construction for solid houses is nearly unattainable.

It is not about the airtightness of the entire building but about the airtightness of the foil. Even just a wrongly driven nail, as an example, is enough to let moisture into the insulation and to the wood.

There are wall constructions without foil as a vapor barrier. There are also house providers who do without assembly foams and install tested and environmentally friendly materials. Just google [Wir-Leben-Haus].

I also think there is an association or something similar.