It is 2.46m in the ground floor from the finished floor to the ceiling plus 22cm concrete ceiling and 16cm floor construction in the upper floor. So the staircase has to bridge a height of 2.84m.
@ TE: some objections have been raised that you probably want to check first.
Nevertheless, it is nice and helpful for those answering if you also address the questions.
Here in this section drawing you can see it clearly:
254 cm room height from finished floor to ceiling below
280 cm story height, including the ceiling ... and that is the height the staircase has to overcome.