The National Building Code on Stairs Provides that:

1. The minimum width of any stair slab and the minimum diameter dimension of any landing should be at least 110 centimeters.
2. The maximum rise of stairs step should be between 17 and 19 centimeters. A rise less than 16 centimeters nor more than 19 centimeters is not considered as ideal stair.
3. The minimum width of a tread exclusive of the nosing shall be 25 centimeters.
4. The maximum height of a straight flight between landing is generally 3.60 meters except those serving as exit from places of assembly where a maximum height of 2.40 meters is normally specified.
5. The number of stairway in a building depends upon the number of probable occupants per floor, the width of stairway and the building floor area. The distance from any point in an open floor area to the nearest stairway shall not exceed 30 meters and that the corresponding distance along corridors in a particular area shall not exceed 38 meters.
6. In building of more than 12 meters high and in all mercantile buildings regardless of height the required stairways must be completely enclosed by fireproof partitions and at least one stairway shall continue to the roof.