Why not? Why do I find something like this in front of you? It is your property after all. The general contractor will not hold your hand. You have to provide him with all the information. You will have to ensure the buildability and obtain permits.
It also says there...
Public Display
The draft of the 1st amendment to the development plan No. 48 "Am Felsenkeller" and the draft justification are available in accordance with § 3 para. 2 of the Building Code
during the period from 10.07.2018 to 10.08.2018 inclusive during opening and consultation hours in the office and administrative building of the Samtgemeinde Rodenberg, Amtsstr. 5, 31552 Rodenberg, publicly displayed......
Based on the mentioned period, one can already see that the amendment must be very recent.
Well, be that as it may, all the better with the 2 full floors, right?