Stairs or steps used in a horizontal exit.

This applies:

• in buildings described in Sentence 1.3.3.2.(1) of Division A, to:
  • interior and exterior exits, as stated in Appendix Note A-3.4.6., and
  • exits serving floor areas that are intended for occupancy, including mezzanines as stated in Sentence 3.4.2.2.(1), and
• to horizontal exits in buildings to which Part 9 applies [see Sentence 1.3.3.3.(1) of Division A for application of Part 9], as stated in Sentence 9.9.2.1.(3).

This also applies to:

• stairways used by the public as access to exits, as stated in Appendix Note A-3.4.6., and
• tents and air-supported structures, as stated in Sentences 3.1.6.1.(1) and 9.10.1.2.(1).

To limit the probability that persons moving through a horizontal exit in an emergency situation will have difficulties in their movement, which could lead to delays in the evacuation or movement of persons to a safe place, which could lead to harm to persons.

To limit the probability that a person using a manual wheelchair or other manual mobility assistance device, or having other mobility limitations, will be unable to move through a horizontal exit in an emergency situation without assistance from another person, which could lead to delays in the evacuation or movement of persons to a safe place, which could lead to harm to persons.