Who is responsible for the following defects?

Hello We have a semi-detached house in financing. The result should come in the next [time period]. Now for your information; the garage is directly attached to the neighboring house (not to the semi-detached house) but to the other neighbor, built directly adjoining! Now I learned that the neighbor is insisting on his boundary and the garage should be moved forward because no boundary was observed! The new or current owner is supposed to do that according to the neighbor. He does not know that we are getting the house.... He is having a dispute with the current owner and we are supposed to say nothing. For 20 years this was not a problem but now he wants it done because the garage of the semi-detached house is encroaching and pressing against his wall. Now: the notary contract is not signed: should we sign it like that and say afterwards what about the garage? Who has to pay for it???? Thank you for your help

Record in the notary contract that the seller is responsible for it. Disadvantage: you may have to sue for it. Better: price reduction Alternative: have the building authority come to assess the whole thing

Now: the notary contract is not signed: should we sign it like this and afterwards ask what about the garage? Who has to pay for that????

The owner. So the current one. If you sign without a note, then you are the owner. So, agree with the current owner: get an offer on how much it costs and then reduce the price accordingly.

I wouldn't sign anything at all at first, but insist that the property/garage be surveyed. At the expense of the current owner.
It must also be checked whether there really are problems with the neighbor's house. Because that would have to be paid for as well.

Once you have signed and the formalities are completed, all claims from the neighbor are directed against you. That means you will not only pay the many thousands of euros for the demolition of the garage, but also damages to the house, provided the garage was the cause.

You can try to negotiate the price of the house. But keep in mind that it involves the demolition and rebuilding of the old garage. I would roughly estimate about 30-40k€ for that. Plus any possible damages. And probably the unfavorable redesign of the property.

So proceed with caution.

From a human perspective, I would do everything to ensure that the trouble sticks to the old owner + everything is settled to the satisfaction of the neighbor before the purchase, etc.

There is also the suspicion that the garage was built without a building permit. Whether it may be rebuilt at all is still up in the air.