The “means of egress” requirements are part of the International Building Code (IBC) that refer to the ability to exit the building in the event of an emergency. The IBC is a set of requirements for the construction of new buildings and alterations or additions to existing buildings. The code requires at least two means of egresses for buildings with less than 500 occupants, three means of egresses for more than 500 occupants, and four means of egresses for more than 1,000 occupants. One of the few exceptions is for small buildings such as mercantile spaces that only require one exit.
Means of egress consist of three parts:
- The pathway to the exit
- The exit
- The exit discharge
There are many regulations concerning each part, including but not limited to emergency lighting, an unobstructed path, a compliant doorway, and the stair tower or ramp system that leads occupants outside and away from the building. The last part, which is the exit discharge, is typically the most common compliance issue. Check out detailed ADA and IBC regulations for steps, ramps, and handrails.
For first floors, ADA ramps and ADA stairs can serve as the accessible means of egress. *It is important to note that not all exit stairs are part of the egress path. If the stairs do serve as an egress path, there must be an “area of rescue assistance” either on the stair landing or directly inside the building by the door.
Any floor above the first floor must also be accessible by persons who are not able to use stairways, and ADA ramps are not typically the ideal solution for multi-story buildings. Therefore, there must be either an elevator equipped with standby power or a stair tower(s) with an “area of rescue assistance” where people can wait for emergency responders to help them.
Below are the specifications for above-ground and multi-story means of egress.
- Either a floor or landing is required at both the top and bottom of each stairway, and they must be at least as wide as the stairway.
- Landings should have a length, measured in the direction of travel, no less than 44”.
- A flight of stairs should not have more than a 12′ vertical rise between floors or landings.
- Stairways are required to be .3 inches wide per occupant but no narrower than 44”. If the egress serves more than one floor, only the occupant load of each floor needs to follow the width ratio.
- Stair riser heights should be between 4″ and 7″ while tread depth should be at least 11″.
- Handrail height, measured above stair tread nosings or the ramp slope, should be between 34” and 38”. The handrails must be continuous.
- Exterior exit stairways that are part of the accessible means of egress for the exterior area for assisted rescue should provide a clear width of 48” between handrails.
- Outdoor stairways and outdoor approaches to stairways should be designed so that water does not accumulate.
For more detailed specifications, visit the ICC‘s Means of Egress Chapter.
Engineered drawings for typical means of egress:
30″ ADA Step Riser Means of Egress
12′ ADA Straight Step Riser Means of Egress
14′ Switch Back Stair Tower Means of Egress
30′ Straight Ramp Means of Egress
30′ Switch Back Ramp Means of Egress