Wall and Ceiling Work - Decision Aid

Uh... interior plaster is not a special request! You’re not telling me that a 10k€ plus item is simply not included? Or are the interior walls of the exterior walls covered with gypsum boards?

Under woodchip wallpaper it should at least be Q2, but maybe this preparation is included in the "woodchip package" and if you say "leave out the woodchip," you might really only get Q1... that’s up in the air.
The problem is more that if you say leave it out and then do it yourself, you’ll likely only be allowed to do that after handover by the developer, meaning when floors are in, tiles on the walls, sockets and switches installed, doors in place, etc... Then it no longer makes sense.

Literally, it says in the construction description:
"All interior wall and ceiling surfaces will receive joint filling by the painter to prepare for the woodchip wallpaper. The ceiling and wall surfaces will be wallpapered with medium-grain woodchip and coated with a white dispersion paint."

In the related passage about self-performance, it says:
"All filling work inside the house. This includes filling the interior wall and ceiling surfaces (concrete, sand-lime bricks, drywall components). ... Furthermore, the buyer must take appropriate measures to prepare the substrate and bridge hairline cracks before applying their wall coverings."

Unfortunately, there is no mention anywhere about plastering itself...

I've thought about that too... that's why I would at least like to have the filling done by the executing company (if possible) – otherwise it definitely makes too much mess. I think I first need to get concrete details from the builder before bothering you further with it. Too bad... but thanks already!