Floor plan optimization, renovation of a two-family house into a single-family house, built in 1957

please describe what the staircase currently looks like. So material, appearance, walkability, etc. I would actually tend to just beautify it if necessary.

Between the basement and the ground floor there is a bright tiled concrete staircase, from the ground floor to the upper floor a wooden staircase from the year of construction, boarded white from below (and wallpapered). Photos will follow. We thought of leaving the concrete staircase with a new floor covering, but we are still undecided about preservation. On the one hand, the underfloor heating with its construction will probably be a problem, on the other hand the 60s staircase does not really suit our taste. The question is also whether it is sufficient (to get rid of the two-family house character) to open the stairwell wall on the ground floor from the new WC wall and to install a glass element with glass door for thermal and fall protection reasons, or whether the door should perhaps be moved further inside, into the extension of the wall between the wardrobe and kitchen in order to basically add the hallway to the stairwell.

My dad separated the ground floor from the attic with a glass door, just as you described. I don't know if it's due to getting used to it, but we don't notice it at all. However, energetically the door is immediately noticeable. So from that perspective, a clear yes to the glass door from me in an old building. I think a nice staircase is very important in my house. Everyone has their own priorities there. If underfloor heating is going to be installed anyway and then has to be adjusted, I would treat myself to that. ;)