House inspected, what’s the next step?

I’ll take a bit of a guess here, they could be Eternit panels. How does it sound when you tap on them?
If they are Eternit panels, there is quite a possibility that underneath is a timber frame in weathered original post-war condition; the window size and how deep they sit in the reveal could fit. However, that would not necessarily be a deal-breaker, the ventilated (because of the battens) often preserves the timber frame.
If Eternit panels are pulled down far and have been on the wall for a while, they often have damage spots at the base where someone has bumped into them roughly. Sometimes there are also narrow spots where the craftsman couldn’t get in. At such points, one can often take a look at what’s "underneath." But normally there is no timber frame at the base, even if it is built in further up.
I would consider a specialist necessary.
Best regards
Gabriele

I would have also guessed Eternit. It is often like that.

I’ll take a bit of a guess here, those could be Eternit panels.

In the thumbnail I would have guessed that too, it looks like roughly square individual panels – at least if you imagine you can actually see anything on it. But in the larger picture it looks like these are not panels, but rather plaster with decorative grooves. More pictures – please no tightly cropped shots and no gigapixels – could bring clarification.

And if it really is fiber cement (brand name "Eternit"), it is interesting to know when it was installed on the house. Older models may contain asbestos.

Yes, we honestly have that concern too. However, during the viewing we didn't think to ask what the facade is made of or if there are any records about it. The problem is simply that we have to submit an offer by next Thursday. I will try my luck with the realtor to find out something. Isn't there usually a second viewing appointment? I've attached a picture again. Unfortunately, it can't be any better. Regards, Alex

If it is Eternit, there is a table on their homepage that shows which products were manufactured with asbestos until which period.

Unfortunately, a direct link to the table is not allowed here, but using Google, "Eternit Asbest bis wann" quickly leads to the desired *.pdf document.