Single-story construction - is it possible to plan a dormer on the upper floor?

No, between 1.0 and 2.0 m it is counted as half.

That is not correct!
The area that has a height of 2.30 counts.

Thank you.
So, from 1m to 2.3m, half is counted.
Under 1 m, how is it counted further?

No, nothing is calculated at half for the number of floors. The area that has a floor height of 2.30 m or more counts; everything lower does not count. Half credit belongs in the calculation of living space. A completely different matter.

Thank you. So from 1m to 2.3m, half is counted. How is it counted below 1m?

Delete the answer from 11ant. It is wrong. Forget it! See mine and

Delete the answer from 11ant.
It is wrong. Forget it!

It is not wrong, these are just two different things:

Living space)
the calculation is uniform nationwide. Under 1m room height not at all, between 1m and 2m half, only from 2m full.

Full floor definition)
this calculation differs depending on the state building code. Where the states, as far as I know, agree is 2.3 m floor height regarding which area in the attic counts at all, and 1.4 m average projection from the ground regarding whether a basement counts. Differences exist in the relation of this attic room area in the 2.3 m or higher range to the area of the floor below. One state building code can say two thirds and another three quarters.

And – without having read all sixteen state building codes – I think in some it may also play a role to only partially count the low areas – otherwise, why else have we here already discussed several times how much knee wall and/or dormer opens the full floor trap?

Regarding Schleswig-Holstein, the quote here in post #1 says that the local state building code does not consider this aspect.

Huh? Maybe you should just answer the question of the OP and not come up with floor area calculations.... even though the story height also depends on the KS, nothing here is "halved or added like that." Gibberish only confuses and does not become more correct with many sentences.