Section 47 in Kerala Municipality Building Rules, 1999
47. Spiral stair fire escape.
(1)The use of spiral staircase shall be limited to low occupant load and buildings upto 9 metres in height unless they are connected to platforms such as balconies and terraces to allow easy exit.(2)A spiral staircase shall be not less than 150 cm. in diameter and shall be designed to give adequate head room.
