I also have doubts about the lawfulness of the remaining useful life. My house is quite new, commissioned in the year 2000. My parents' house is almost 100 years old and at some point probably only demolition remains, because it cannot be economically renovated. They simply form an average value from both houses...
I think that is not correct. In my opinion, each building is assessed separately and then depreciated over 80 years according to the respective year of construction.
The whole property tax issue annoys me a lot anyway, especially since it ties up huge amounts of lifetime. For me it is added that the tax assignments get diluted because my parents as landowners will in the future only have one single property tax number under which my house is then listed. Until now, we had four different property tax numbers. I don't want to eventually have to pay inheritance tax on my self-built and self-financed house because it is attributed to my parents' assets...
If I remember correctly, you had a structure worked out by a tax advisor and a specialist lawyer where the civil law owner is different from the tax owner. From my point of view, it would be especially important now that a tax advisor reviews your assessment again.
I can only really advise everyone to file an objection against the foundational assessment notice now and, if necessary, sue in order not to be cut off from legal recourse later when the property tax notice arrives. This two-stage procedure alone, where people now have to fill something out and cannot yet see what kind of property tax it will ultimately lead to, in my opinion violates the constitutional principle of legal certainty.
By the way, it was already like that with the two notices now. A foundational assessment notice based on the values from 1964 or 1935 was issued and then the property tax notice. Even then, one would have had to file an objection against the assessed value notice.
By the way, one can now nicely see in principle what would come out if a wealth tax were introduced. Real estate assets are only a small part of what has to be assessed.