Is the standard land value for a building plot in a private sale binding?

Hello, I would like to know to what extent one has to orient oneself to the [Bodenrichtwert] when selling land. I would like to buy a building plot (750 sqm) from my wife's uncle, which is not developed and overgrown with large trees. The [Bodenrichtwert] in the neighboring town is €220/sqm. There is no value available for our village. Her uncle would like to sell us the plot very cheaply because he does not need the money. How far can one deviate downward from the [Bodenrichtwert] without having problems with the tax office?

The land reference value is, as it already says, merely a reference value. In addition, it always refers to a standard parcel! Your property may differ in terms of size (possibly oversized) and of course location. Also, it may be undeveloped, but you have to check what the LRW is defined for. The tree population can certainly be considered as depreciating.

Basically, I can also sell the property to the uncle for a euro, but the fees will probably not be calculated based on this "euro", instead the LRW will be used. So, with regard to property taxes and the tax office, a gift might be involved.

Is there really no separate LRW? Because actually these must be published nationwide. Otherwise, you can take the €220; if this applies to a developed property, you can deduct the development costs. Then possibly make a deduction for the trees (clearing costs) and depending on that, also for the size or shape of the property.

I would be interested to know to what extent one has to orient themselves to the standard land value when selling a plot of land.

Not at all. That is a benchmark from the past for a predefined plot (e.g., for an average size/utilization/street frontage).

As already mentioned: The standard land value is not binding. However, authorities may, in the worst case, assume "fraud" if the sale price is too low and suspect that there is an official and an unofficial purchase price component to save taxes & fees. Therefore, as always, the advice: consult with a specialized lawyer about the project. An initial consultation does not cost much and ultimately saves a lot of money and trouble.

For how much does he want to sell it? If the difference is not too big, the tax office will usually just accept the purchase price... however, if the difference is quite large, it can look different

If it sounds right, he would theoretically even give it to them for free. So the question is more about what the lowest possible price they can set without getting "problems."