1. First, the number of steps is determined by the height of 2.8 meters. Generally speaking, if there are old people and children at home, the height of the steps should be between 140- 160mm, which is too high and steep to walk.
2. So this staircase should be set to 18-20 steps. As can be seen from the fact that the central column is only φφ 140mm, you are not going to make the clear width of this staircase too large, otherwise the central column can't bear it.
3. The width of the ladder should be within 800mm. If calculated by 800 mm and rotated 360 to the top, the widest part of each step will be 273-303mm (corresponding to 20- 18 step), and the width of the step center is not very generous, but it is still possible to walk. After all, indoor space is too precious.