Is a letter of intent to purchase binding?

We intend to give up and sell our house in xxx and buy a condominium in xxxx. The seller has presented us with a letter of intent to purchase which we are both supposed to sign. Question: Is a letter of intent to purchase binding? For example, it could be that financing does not go through. In my opinion, a letter of intent to purchase is a "pure letter of intent" and as long as it is not notarized neither the buyer nor the seller is forced to carry it out. Correct?

Question: Is a letter of intent to purchase binding?

It does not constitute a purchase contract. That is only possible with a notary.

Perhaps something can be derived privately from the declaration – for example, if you then do not buy and the seller declines other interested parties and thereby incurs costs which he wants to recover from you. Of course, the same applies vice versa.
I have not seen this yet – but I am not a lawyer either.

Yes, that is just a written handshake.

However, if costs are incurred during the contract preparation, they will be passed on to you. Because you have implicitly triggered them with your declaration.

In my opinion, it should be understood as a preliminary contract. You sign a contract for the execution of the property purchase. If the property purchase does not take place because of you, you have broken the preliminary contract and must live with the contractually agreed consequences (penalty, assumption of already incurred ancillary purchase costs, or something else).

In my opinion, it should be understood like a preliminary contract. You sign a contract for the execution of the property purchase. If the property purchase does not take place because of you, you have breached the preliminary contract and must live with the contractually agreed consequences (contractual penalty, taking over already incurred ancillary purchase costs or something else)

I strongly doubt that. Without notarization, claims can hardly be enforced. Even with a fee-based reservation agreement, the customer can demand their money back if they no longer want to buy, because according to the Building Code, every contract without a notary is invalid. There are many rulings about this on the internet.