1– The ramp slope of more than 5% should not be designed as it will be difficult for people with physical disabilities to move.⠀
The optimal slope of the ramp is no more than 5% (about 3°).
2- The slope of the stairs should be no more than 33 °.
The optimal staircase slope is 26-33 °
3- The inconvenient size of the steps is less than 280-300 mm in-depth and more than 150-180 mm in height.
To make it convenient to go up and down the stairs, the steps should be 300 mm deep (rise) and 150 mm high.
4- Standard depth range 1000 – 1500 mm.
Optimal dimensions of stair steps in public and residential buildings.