Buy land and then have it developed

Oh man, damn ... Why does it always have to be so complicated. The problem is, the development, re-surveying, trees, access road, notaries ... Altogether I currently estimate it at about 75,000 euros. And the money is of course not just there, but comes from me. And I would have also liked to avoid an appraiser. As far as I know, however, the appraiser has to come if the property is transferred at a reduced price within the family. Otherwise, it would be quite simple. We pay the standard land value - development costs.

Oh man ey ... That this always has to be so complicated.

I don't think so at all.

We pay the standard land value - development costs.

Yes, that would be the easiest, right? I haven’t understood yet what speaks against it? However, I’m not a tax expert. You first set the price for the property yourselves. If you can credibly convince the tax office that price X = standard land value - development costs, that should in my opinion not be a problem. Usually, a value that is not more than 20% below the real value (standard land value - costs) is still accepted or is only examined more closely starting from this threshold. Especially among relatives. Therefore, I would aim for a notarial contract here, where the standard land value is undershot by maybe 10% and also all costs are deducted.

Oh man ey ... Why does it always have to be so complicated.

You're making it difficult for yourself.

Theoretically, you could simply give both a loan, they handle the development, etc., and you buy regularly at the BRW. The two loans would then be offset in the notarial contract.
But you wanted to buy under BRW and keep the tax office out if possible.

Since you apparently don't want to post any numbers, no one can say whether you'd even have a problem with the gift or not.