4 years after construction, the office also demands land acquisition tax on the house

Thank you. I found the following on the internet: “Important: Both contracts must be separated in time and content. There should be at least half a year between them. And you should not buy the land from the company that builds your house.”

What is stated on the internet is not always correct. Your quote is simply wrong in terms of content. ONLY if the purchase of the land is tied to a specific home builder does the real estate transfer tax apply to both. Then both contracts are considered connected/coupled contracts, as with a property developer (who also sells land and house together). It may happen that the tax office contacts you and demands payment. However, you can simply counter this by presenting the purchase contract and the independent construction contract, and the issue is settled.

Thank you for your feedback, that sounds reassuring. I will double-check with my tax advisor to hear his assessment.

Can something like this also happen due to the temporal connection of two otherwise independent contracts? Even if it is a municipal plot with free choice of developer? I once read something of that kind somewhere.

Out of interest: what I believe was not considered in any answer is "municipal" – is there actually a case where a plot is sold by a municipality as a linking transaction?

"Municipal" - is there actually a case where land is sold by a municipality as a tied transaction?

Never seen it. But Germany is big.

Can something like this also happen due to the temporal connection of two otherwise independent contracts? Even if it concerns a municipal plot of land with free choice of developer?

And it is also important here not to speak of the developer, but of the general contractor, because a developer sells house and land together.

Exactly. "Free choice of developer" is a contradiction in terms: if you can freely choose the general contractor, he is at least in this case not acting as a developer (= commercial builder for the purpose of creating developed plots).

Out of interest: what I think has not been considered in any answer is "municipal" – is there actually a case where a plot of land is sold by a municipality as a tied transaction?

Municipal settlement companies typically do not act as developers, as in the production of multi-family residential buildings they only operate for their own rental purposes, and never as general contractors for third parties (except their parent company) (based on municipal economic law). When municipalities sell previously undeveloped plots, they practically never do so bundled with developer activity. Anyone who at the tax office would suspect a tied transaction here would have to be a trainee in their first year of apprenticeship; otherwise, they would be familiar with the basics of public sector economics. It is more likely for a camel to pass through the eye of a needle or for a rich person to enter heaven than for a municipality to first improve building plots by development before selling them. Also, I have at least never heard of a municipality selling the plot and awarding the development contract to its settlement subsidiary. And I have been doing housing planning for over 40 years, although only involved in municipal politics since 1993. Occasionally, municipalities steer a development area so that WA1 is exclusively marketed through Huberbau and WA2 exclusively through Meierbau. However, regularly these companies, and not the municipality, are the sellers in the purchase contract. This is at least appropriate and reasonable for semi-detached or terraced housing development – unfortunately, the mayor of Schilda of neglected this. For single house plots (E, not E/D), such steering would be absolutely unusual.

Thank you very much for the additional explanations, that reassures me.