Retaining wall 2 m high without static report?

On the one hand, "other things had to be submitted later" doesn't exactly sound like you made it easy for the caseworker to happily stamp the approval; it also somewhat smells like a rejecting neighbor with connections who might have encouraged nitpicking; and besides, I've frequently had the impression in homebuilder forums that the layperson's idea of (freely after Johanna von Koczian) "a little earth pressure" suggests that a closer look would be advisable.

My architect told the building authority that no static analysis is required because up to 2 m is exempt from approval.

That is a strange justification. Dividing a construction project that is temporally and/or functionally connected into parts that require approval and parts that do not is not permissible. Then you would have to tackle the terrace and the retaining wall after completing the house, although the functional independence could still be disputed. In any case, the architect's statement sounds like an excuse to me.

What is actually correct?

The authority must, at the latest upon inquiry, state the legal basis for its demand. Have you spoken to the caseworker yourself? If you are lucky, you will get an explanation. Just keep in mind that this explanation might shake your trust in your architect.

Well, we are just young and inexperienced or rather somewhat naive when it comes to building a house. The lady at the building authority neither communicated a letter nor anything else. There was only contact through the architect, who is also known as the construction manager. I am trying to reach the building authority further and then we'll see.

Thank you all.

Hello, just ask about the passage in the Landesbauordnung or look it up yourself and talk to the colleague about it. On the other hand, if you are building with L-blocks, for example, the static supports from the manufacturer are enough. At least that's the case for me...

Just to finally close the topic. We actually hired a structural engineer who assessed the stability of the L stones with a height of 2 meters (which only cost 250 euros). This was then rejected again with the reference that a fire protection report was missing. The structural engineer then called the office and explained that L stones do not really pose a fire risk. Two days later, there was the red dot.