Planning stair treads and beams

Hello,

we have the following problem.
We are currently renovating an old building and are now in the final stages of planning the staircase.
I have attached the drawings.
The problem is that we wanted a staircase that is not too narrow and with the largest possible tread depth.
But since we have a beam in one spot, which our staircase builder apparently did not fully take into account, I am not sure which version we should choose.
We would like the 26 cm tread, but then the staircase would not comply with DIN and from the second step it would be quite close to the beam.
The beam is at 231.9 cm. The second step has a height of 39 cm. But since it is under the beam, it should just fit. However, I am afraid that it might look too cramped and rather like a cellar staircase.


With the shorter tread of 25 cm, I am afraid that it might feel too short. But it would comply with the standard and, unlike the other staircase, it would meet the DIN requirements.



Until recently I was absolutely sure that we would take the 26 cm tread. But after the staircase builder remeasured after the screed, unfortunately the step dimension rule no longer fits and it would no longer be DIN compliant. However, the staircase would still be very comfortable to walk on.
I am confused right now and don’t know what to do. I think I’m just overthinking it, aren’t I?

In any case, all steps should be the same height, otherwise there is indeed a risk of tripping. A tread of 25cm is also OK, the difference is hardly noticeable compared to 26cm, and you can also choose steps with a small overhang, making the tread slightly larger.

But another idea - the stairwell opening is there. Would it be structurally possible to simply turn the staircase around? So that it doesn’t go up from the back right to the front left, but from the front left to the back right? Then the problem with the beam would resolve itself, since it is on the right side. Then the 90° bend would be at the bottom instead of the top. You would just have to make sure that you can access the staircase from the front left at the bottom, and there should be no load-bearing wall in the way, for example.

We have a size 25 fitting and my shoe size is 46/47. That's okay but a bit more (I think 1cm would definitely be noticeable) would be better. --> Without knowing your shoe size, I would advise you to go for 26 if possible, although 25 hasn't been a big deal for us so far, literally speaking. However, if this increases the step height (which seems to be the case for you), I really can't help you.

I wear size 47 shoes
Turning the stairs around is not possible because there is a cellar staircase below. We also specifically removed a piece of the ceiling so that the staircase would fit. The staircase was previously reversed But this way it fits exactly into the concept.
I recalculated with a staircase calculator and it will probably be 25.5 tread. It slightly misses the DIN standard with 65.3 in the stride measurement rule. But the rest fits. With 26 cm it gets too tight with the beam. But this way it could work.

We do not find the 19.9 rise to be bad, since at my in-laws we have almost a similar staircase with 19.9 rise and 25.8 tread.

The staircase builder also proposed a staircase with one more step and only an 18.68 rise and a 25 tread. But we find that staircase too narrow at 85 cm.

Well, with an old building renovation you cannot have everything