Reopen floor slab for new staircase. Support ceiling in the middle?

And again make a ceiling breakthrough to have a staircase installed. My doubts can no longer be dispelled or answered by the previous owners as to whether I have to make a support for the beam directly next to the breakthrough.

I still don’t understand the question. There was an opening in the ceiling for the old stair access. If there was a staircase there before, it should be possible today as well, right? Only drawings and photos as well as information about what kind of new staircase is to be built will really help. As it stands, your post is completely incomprehensible.

Here is a sketch. My question is whether something needs to be supported or not. I don’t know if the ceiling was supported at the time of the old stairs.

And the staircase should be it then

The staircase should be back where it is drawn

Then just do it. That is how it is planned anyway. The stair builder should build a staircase as originally planned. Maybe the load capacity is not sufficient for a concrete staircase, but other than that, I don't see what other beams or supports would need to be installed ;-)

All right, then I thank you very much. And have a productive day.