Architect wants their own structural engineer

Hello,

there is always something new ...

The architect insisted on using "his" structural engineer.

Now I have the structural report, but without a green approval stamp, instead with the remark "This structural report may only be used for execution after approval by the building authority or a state-certified inspecting engineer."
How is that supposed to work? I thought I was paying a lot of money for it to be okay.

He recommends a lot of things for the old house, half of which I still need to have explained to me. In addition, the builder only shook his head about some things. Since he has already renovated several old houses, I am inclined to also rely somewhat on his experience.

Does the structural engineer have to approve it himself in the end or does the building authority do that?

I'll assume Germany.
Which would then be federalist,...;)

Depending on the [Bundesland], such things are regulated differently.

Putting statics aside, wouldn't a permit-free procedure have been sufficient for a renovation, for example if it’s just an attic conversion?

The statics are handled internally in my office, but you usually do something like that to have as few problems as possible during planning and implementation.

Best regards