In that case, I would then make a private preliminary contract (there are plenty of templates available online) and make a down payment. Every non-notarized contract is worth nothing at all. Have fun proving it and suing for compensation, but you still won’t have the apartment. Definitely no down payment, the money could be gone. A pre-emptive right doesn’t help either, because then you step into the new purchase contract and price. If in 6 months someone pays 20% more, you can either follow or let it go. Completely circumventing it is also easy with a sale to the children at a very high price and an independent cash gift. Apart from higher notary costs, this has no disadvantages.