Do I need a building permit for roof renovation?

Hello forum,
we have bought a semi-detached house.
We need to renew the roof and the cladding of the dormer.
The roof will be doubled up with 10cm beams and a black covering will be installed (the roof structure will be raised by about 20cm), additionally the roof overhang will be widened to 15-20cm.
The dormer is to be clad with slate.
Nothing will be changed in the statics.
Now to my question: do I need a building permit for this or is the measure exempt from approval?
There is no development plan in the area.

I look forward to your answers.

Best regards from Neumünster in the far north.

Without knowing the legal situation exactly. I would do it and not ask anyone, because no one will care anyway.

You have to report the construction site anyway. On that occasion, you will find out.

Who indicates where such construction sites are? This is not construction, but maintenance.

No construction sign with a red dot during a roof renovation? Then I have just learned something new and hereby withdraw my comment. So just ask the building authority.

Ok thanks already for the answers.
Hope for a reply through a short channel :D
Has anyone somehow already had experience regarding this?
My building authority is extremely hard to reach.