Staircase in the floor plan okay? What does the number 18.3/28 mean?

Oh dear, that sounds again as if the staircase was not well planned by the architect. Although we just measured the step length in our current apartment. We come to 28.2cm which is very comfortable for us. The 28cm in the floor plan would therefore be good in my opinion. Smaller we would not find so great, but we are also people with shoe sizes 41 and 43...

I have now also read up a bit. Based on the values, one can apparently draw conclusions about the steepness of the staircase and accordingly how comfortable and safe the staircase can be used.

What do you think, should I bring this up again with the architect or is the step height still tolerable?

Thank you all for the information.

Architect: 18.3/28
Floor height should be 292.8 for you

From my profile:
Step measure = 2x rise + 1x tread - IDEAL: 63 cm for you so 2x18.3 + 28 = 64.6
Comfort = tread - rise - IDEAL: 12 cm for you so 28 - 18.3 = 9.7
Safety = tread + rise - IDEAL: 46 cm for you so 28 + 18.3 = 46.3

To adjust the comfort factor, at least one more rise would have to be added (staircase will then be longer).
It would then be 17.2/28

Step measure = 2x rise + 1x tread - IDEAL: 63 cm for you so 2x17.2 + 28 = 62.4
Comfort = tread - rise - IDEAL: 12 cm for you so 28 - 17.2 = 10.8
Safety = tread + rise - IDEAL: 46 cm for you so 28 + 17.2 = 45.2

This would probably be somewhat more comfortable, but the staircase will be about 28 cm longer.

Architect: 18.3/28
Your floor height should be 292.8

From my profile:
Step measure = 2x rise + 1x tread - IDEAL: 63 cm, for you it is 2x18.3 + 28 = 64.6
Comfort = tread - rise - IDEAL: 12 cm, for you it is 28 - 18.3 = 9.7
Safety = tread + rise - IDEAL: 46 cm, for you it is 28 + 18.3 = 46.3

To adjust the comfort factor, at least one more rise would need to be added (the staircase would then be longer).
It would then be 17.2/28

Step measure = 2x rise + 1x tread - IDEAL: 63 cm, for you it is 2x17.2 + 28 = 62.4
Comfort = tread - rise - IDEAL: 12 cm, for you it is 28 - 17.2 = 10.8
Safety = tread + rise - IDEAL: 46 cm, for you it is 28 + 17.2 = 45.2

That would probably be a bit more comfortable, but the staircase would be about 28 cm longer.

Huge thanks for the calculation. I could follow your calculation very well. Thanks :)

According to our architect, another step would not be easily feasible. The discussion about this was a long time ago, unfortunately I don’t remember the reason anymore, but it was plausible at the time. Do you think we could live with the current values? Regarding the safety calculation, we are very close to the ideal value. Safety is the most important thing for me personally when it comes to stairs, or more important than comfort.

The current comfort value deviates from the ideal value by 2.3 cm. Unfortunately, I really can’t tell whether this value is so badly off that every time we use the stairs it will be a misery, or if the value of 9.7 cm would still be okay. Do you think we could leave the staircase as it is without regretting it later?

I think so, but take a tape measure in your pocket for a while and "rate" stairs you are currently using with comfortable etc. And then measure the dimensions each time. Keep in mind how the tread depth is measured for overlapping steps.

should I bring this up with the architect again?

I tend to say no, but without knowing the stair layout, it is difficult to judge. For straight stair flights, this dimension seems certainly well chosen to me.

I tend to say no, but without knowing the staircase floor plan, it is difficult to judge. For straight stair runs, the dimension certainly seems well chosen to me.

Then I’ll post the staircase...