International codes govern building of stairs.
The International Building Code (IBC) is a set of model ordinances that is available for adoption and use by any municipal governmental jurisdictions worldwide. It provides for minimum health, safety and welfare regulations for the general public.
Chapter 10 of the IBC is titled "Means of Egress" and covers the standards for stairways in two separate sections.
Purpose
The purpose of IBC Chapter 10 is to protect the occupants of buildings by giving them the means to safely relocate from one part of the building to another or to evacuate the building through the available exits.
Section 1009 (Stairways), Section 1026 (Exterior Exit Ramps and Stairways) and Section 1028 (Assemblies) are the parts of the chapter that deal specifically with stairs.
Definitions
Section 1002 (Definitions) sets the definitions for terms used in Chapter 10:
A "means of egress" is the ability to leave a building via an unobstructed passage.
A "stair" is a change in elevation consisting of at least one riser. Multiple stairs make up a stairway that can be either internal or external to the building. The code provides that exit stairways must have a clear width of at least 48 inches between the required handrails.
Stairways
Section 1009 consists of 14 separate subsections that address such topics as "Headroom," "Vertical rise," "Spiral stairways" and "Handrails."
Exterior Exit Ramps and Stairways
Section 1026 consists of six separate subsections that address such topics as "Exterior exit ramps and stairways" and "Exterior ramps and stairway protection."
Assemblies
Section 1028 consists of 15 separate subsections that address such topics as "Width of means of egress for assembly" and "Common path of egress travel."
