following are some of the general guidelines to be considered while planning a staircase:
• The respective dimensions of tread and riser for all the parallel steps should be the same in consecutive floor of a building.
• The minimum vertical headroom above any step should be 2 m.
• Generally, the number of risers in a flight should be restricted to twelve.
• The minimum width of stair should be 850 mm, though it is desirable to have the width between 1.1 to 1.6 m. In public building, cinema halls etc., large widths of the stair should be provided.(1.2 min)