With the eaves height of 5.5 starting from the original ground level, we are also having our trouble, so next week we need to ask the building authority again exactly what is meant. We want 2 full floors - so nothing unusual. That has to be feasible.
The additional regulations with m carport and storage at the boundary are stated in the Bavarian Building Act. That is all known so far. We just have to investigate again how the neighbor is planning, or who submits faster.
We definitely do not want to build the house into the ground, since we are not planning a guest room or anything like that and it would only make it more expensive. According to the development plan, you are allowed to fill up and dig down 1.25m each. That should be enough everywhere, shouldn’t it?