Interior walls: gypsum board or OSB board?

Hello everyone,

at some point we still need to make a decision about our interior walls.

Our home builder presents to us how (Q-)selection to choose the interior walls as follows:

• 12.5 mm gypsum fiberboard + 12.5 mm gypsum board
or
• 13.0 mm wood-based panel + 12.5 mm gypsum board

As for the load, both variants should be comparable, do you believe that? I could actually (gut feeling) imagine that the variant with the OSB board somehow carries more. On the other hand, I’m not quite sure what I would need more load-bearing capacity for, I think a hanging cabinet in the kitchen is the benchmark here and both should easily manage that (even the new desired TV only weighs 35kg).

Since we are planning a controlled residential ventilation and you sometimes hear that the air is supposed to be a bit drier with it, one might now say that the double gypsum cladding might also be able to store and release twice as much moisture. But that is a far-fetched theory of mine...

What would you do?

I’m grateful for your opinions, because at some point we probably have to decide :).

Since we are planning a controlled residential ventilation system and you occasionally hear that the air is supposed to be somewhat drier with it, one might now say that the double gypsum board cladding could perhaps store and release twice as much moisture. But that is a theory of mine that's far-fetched...

Yes, that is far-fetched. The air is at 30-40% in no time in winter if you don’t plan an enthalpy exchanger. It doesn’t matter what walls you have. Unless you spray them daily with the garden hose.

Great idea! I also have one of those pump spray bottles lying around here, it will surely do for the beginning :p.

EDIT:
But I will take a closer look at the enthalpy exchanger... (Does that make sense if you already have problems with dry eyes?)

Does it make sense if you already have problems with dry eyes?

Not only then, always! If you already have problems anyway. Then the question doesn’t even arise. Without enthalpy exchangers you won’t be happy.

Yeah, that's far-fetched. The air drops to 30-40% in no time in winter if you don't plan an enthalpy exchanger. Doesn't matter what kind of walls you have there. Unless you spray them daily with the garden hose.

So-so, here is our recording from January 2021 - without enthalpy exchanger:

Masonry heater, large room volume, clay plaster walls, quite a lot of unsealed wood (acoustic ceiling, gallery, stairs)

Just like with you, Hampshire, it actually always looks like that for me too! On average between 50 and 55%...

If I'm not mistaken, you also don't have a [Kontrollierte-Wohnraumlüftung], right? Well, we currently don't have one either, and therefore a basically good middle ground. But it is supposed to be really problematic with a [Kontrollierte-Wohnraumlüftung]... As I mentioned, I need to inform myself about [Enthalpietauscher]...

I don't really want to focus the discussion so much on humidity now, but rather on what you think about the different wall constructions.