Damp basement wall?

I agree. He has to prove that you knew about it.

1. we could not have known that there was a moisture problem in the basement, among other things because we stored boxes, rolls of wallpaper, and drywall sheets in one room (hobby room, second picture), which in no way were moldy. In the other room (laundry room, first picture), I regularly hung up laundry and it was usually dry in less than 24 hours.

These are all not real arguments. Better don’t entangle yourself in statements that could come back to bite you later. Aka "in dry rooms laundry should already be dry after 19.5 hours, so the basement must have been wet."

2. I doubt that there is even a problem with moisture in the walls.

But the photos (especially the second one) unfortunately tell a different story. And known construction defects must be disclosed when selling.

We will write a response over the weekend and possibly report back here.

Don’t do that. As I said, you entangle yourself in things that sound good for now but will be legally dissected by the opposing lawyer later. A clever lawyer can quickly construct proof from something like that that you actually knew something and concealed it, etc.

Only respond if the buyer demands something from you or has set a deadline. The letter should have come by registered mail. Respond only briefly and concisely: "Objection. Herewith we object to the allegations made by you." and then react to his demand, e.g. "We reject any assumption of costs. Best regards." No explanations, no stories about dried laundry, wallpaper, or anything else. You don’t have to justify that.

No matter what, a lawyer can handle this better in any case and can nip such a looming legal dispute in the bud early on.

Thanks for the answers. We also think the buyer is going too far and of course we will immediately involve a lawyer if necessary.

The whole matter has two aspects for me. 1. We could not have known that there was a moisture problem in the basement, among other things, because in one room (hobby room, second picture) we stored boxes, rolls of wallpaper, and drywall panels, none of which were in any way moldy. In the other room (laundry room, first picture) I regularly hung laundry and it was usually dry in less than 24 hours.

2. I doubt that there is even a problem with moisture in the walls. After all, the employee of a sealing company is a salesperson of his product and not an independent expert.

We will draft a response over the weekend and, if necessary, report further here.

One does not necessarily have to have the lawyer write it directly. But any words/response should at least only be given after legal advice. Unfortunately.

I assume the buyer did not send you the pictures and the report without reason, or just to make you feel guilty.

Regarding the 2nd statement. Um, that looks nothing like a dry wall to me. I definitely think moisture is measurable.

The whole thing came by email. There are no concrete demands in it, but the note that he obviously did not include this defect in his purchase price offer and that the interior sealing recommended by the company is supposed to cost about 26 thousand euros. And then the question of how we should handle the situation and proceed from our point of view.

It is probably really best to speak with a lawyer immediately.

And no, of course we do not write anything about laundry and wallpaper rolls, those are more indicators for me because I wonder if we should have noticed something. And I can clearly say no.

Thank you very much for all the responses.

Sorry, but the email ended up in spam, didn't it?

For me, every email that contains a € symbol ends up in spam :)

You mean, we shouldn't react to it at all?