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Level of exit discharge

  • Thread starter Thread starter DwightB
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DwightB

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2006 IBC:

This has probably been covered before, but a search doesn't really find the info I want. I understand that the "exit" is the exterior door (and other exit enclosures) between the "means of egress" and the "exit discharge". Section 1002.1 says the "level of exit discharge" is the story where that exit door is located.

One question: If I have a sloping site and there is more than one level that can exit directly to grade, is each of those levels a "level of exit discharge"?

Second question: Suppose my exit door doesn't exactly match the surrounding grade and I need a few steps to get up/down to grade after I exit the building. Is that story still at a level of exit discharge? What if I actually need a half-flight or full flight of stairs to get up to grade? For instance, if there is an exterior stairwell down to a "basement" level, then is the exit from that level still considered to be a level of exit discharge if there is a flight of stairs still to climb (or descend, for that matter) while outside the building?
 
Welcome DwightB. Way to just jump into the pond with three quick questions. A building may have more than one level of exit discharge. An exit, such as a stair, would typically only have one level of discharge, although a really strange site could create more than one. The open, outside stairs that take you to grade would be part of the exit discharge.
 
The means of egress consist of three items; the exit access, the exit and the exit discharge. The exit access is that route you take to get to the exit. The exit could be an exit passageway, the rated exit stair or exterior door. The exit discharge is that point you are outside of the exit, usually the outside.
 
As for your second question, it seems reasonable that as upon exiting the building you are now in the exit discharge, so technically you could say that the landing of your outside stairs is defined as the exit discharge, such that the area within the building that you just left is at the level of exit discharge, provided the subject stairs could be considered to provide "direct access to grade" in accordance with IBC Section 1027.1.
 
DwightB, good questions.

I'm not sure where you're getting the definition for level of exit discharge, but the 2006 IBC defines it as "The horizontal plane located at a point at which the exit terminates and the exit discharge begins." If you go through an exterior door and you're on a landing that has stairs to grade, you are not yet in the exit discharge, you're still in the exit. I don't believe the exit discharge begins until you're at the bottom of the stairs.

EXIT. That portion of a means of egress system which is separated

from other interior spaces of a building or structure by

fire-resistance-rated construction and opening protectives as

required to provide a protected path of egress travel between

the exit access and the exit discharge. Exits include exterior exit

doors at the level of exit discharge, vertical exit enclosures, exit

passageways, exterior exit stairways, exterior exit ramps and

horizontal exits.

EXIT DISCHARGE. That portion of a means of egress system

between the termination of an exit and a public way.
 
Look up the definition of public way while you are at it, because the exit discharge does not end until you reach a public way.
 
1. Start with the assumption that if we have a simple slab-on-grade building on a level site, we egress through the exterior exit door and we are on the "level of exit discharge", right?

2. But what if, due to a gently sloping site on a larger building, another exterior exit door is 3 feet above grade, with stairs down to grade? Is that door still considered to be "at" the level of exit discharge?

3. What if instead, the building was partially set into the slope, such that the exit door opened onto a 5'x5' exterior concrete pad landing that was 3' below adjacent natural grade, with retaining walls + stairs to take us up to the natural grade? Is the door still considered "at" level of exit discharge? Is the 5'x5' landing considered to be the grade level of exit discharge?

4. Take questions #2 and 3, and instead of a 3' elevation difference, make it a 7' elevation difference... now we're starting to mess with definitions of what is the first story of the building.

I think these are the kinds of dilemna in trying to determine what constitutes THE level of exit discharge.
 
I'm with TJ on the public way is the end. So if both have to be accessable a whole bunch of stuff may come into play. Couldn't really say much more without a set of plans.
 
There are exceptions to the exit discharge ending at a public way. If a parking lot meets 1,2 and 4 i am not concerned with #3

2006 IBC 1024.6 Access to a public way.

The exit discharge shall provide a direct and unobstructed access to a public way.

Exception: Where access to a public way cannot be provided, a safe dispersal area shall be provided where all of the following are met:

1. The area shall be of a size to accommodate at least 5 square feet (0.28 m2) for each person.

2. The area shall be located on the same lot at least 50 feet (15 240 mm) away from the building requiring egress.

3. The area shall be permanently maintained and identified as a safe dispersal area.

4. The area shall be provided with a safe and unobstructed path of travel from the building.
 
Yikes, in response to your questions:

1. Start with the assumption that if we have a simple slab-on-grade building on a level site, we egress through the exterior exit door and we are on the "level of exit discharge", right?

Yes

2. But what if, due to a gently sloping site on a larger building, another exterior exit door is 3 feet above grade, with stairs down to grade? Is that door still considered to be "at" the level of exit discharge?

No. The exit is the exterior stairway. You don’t reach the exit discharge until the termination of the exit.

3. What if instead, the building was partially set into the slope, such that the exit door opened onto a 5'x5' exterior concrete pad landing that was 3' below adjacent natural grade, with retaining walls + stairs to take us up to the natural grade? Is the door still considered "at" level of exit discharge? Is the 5'x5' landing considered to be the grade level of exit discharge?

Same as answer #2.

4. Take questions #2 and 3, and instead of a 3' elevation difference, make it a 7' elevation difference... now we're starting to mess with definitions of what is the first story of the building.

The level of exit discharge would be determined the same way for a building reagrdless if it were one or twenty stories.

I think these are the kinds of dilemna in trying to determine what constitutes THE level of exit discharge.
 
elevation, or protection as defining characteristic?

1024.1 says "The exit discharge shall be [1] at grade or [2] shall provide direct access to grade." The second one seems to imply that an exit discharge can occur at other than grade level.

1023.6 exception 1 describes a situation in which (for example) a commercial building with its first floor floating 20' above grade on columns could have its level of exit discharge be at 20' above grade.

So it would appear that elevation of the path-of-travel alone does not neatly define the border between termination of exit vs. beginning of exit discharge.

1002 definition of "exit" implies that it has something to do with when protection is required from the interior of the building.
 
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The term "exterior stair" is found in the provisions of 1026, titled "Exterior Exit Ramps and Stairways" (emphasis added) which appear to be intended to address vertical features serving multi-story buildings where the code seeks to clarify that the occupants have not left the building while on an exterior stair, which is anticipated to be structurally supported by the building. Such an exterior exit stair is clearly an exit element, not an exit discharge element. I think the reference to exterior balconies, stairways and ramps in 1024.3 is misleading - the conditions of this provision should be in 1014.5 and 1023.

Consider: Due to the site constraints of high-rise construction, there is often at least one building exit that must utilize an outside ramp or stair feature to reach grade. Based on a strict interpretation of 1023.2, this would not be permitted if the outdoor ramp or stair were subject to the provisions for exterior exit ramps and stairways.

As for a terraced site feature outside the building intended for pedal evacuation (a stair), such as presented by the OP, it may be addressed as an "outdoor stairway" per 1009.5.2. Certainly such an outside stairway, also satisfying 1024.4, could be considered a part of the exit discharge (that portion of a means of egress system between the termination of an exit and the public way). Such a stair located outside the building, after the occupant has discharged to the exterior of the building, would be an exit discharge component, not an exit stair.

Thus, a vertical exit enclosure, exit passageway, or exterior stair could all terminate at the level of exit discharge where occupants then discharge directly to the exterior of the building (1024.1) and traverse the outdoor stairway in order to reach the public way.
 
Aegis FPE - what I hear ou saying is that there is a difference between the exit stairs and exit ramps described in 1002 defintition of "exit", vs. the stairs and ramps in 1023.6:

"exterior exit stair" (1002) vs. "exterior stair" (1023.6)

"exterior exit ramp" (1002) vs. "exterior ramp" (1023.6)
 
What I was trying to express was an apparent distinction between "Stairway, Exterior" (1002.1), "Outdoor Stairway" (1009.5.2), and an "Exterior Exit Stairway" (1023).

Apparently 1002 anticipates that there may be exterior stairways that are not specifically "exterior exit stairways," and 1009.5.2 appears to anticipate outdoor stairways that are not necessarily "exterior stairways."

It can be noted that Section 1023, in the title and every sub-section, uses the term "exterior exit ramps and stairways." I am suggesting that this seeks to clarify that these provisions are applicable where the exterior ramp or stairway is serving as the exit in the means of egress, where the means of egress has 3 distinct elements:

1. Exit Access

2. Exit

3. Exit Discharge

Upon leaving the building or the exit, the means of egress then consists of the exit discharge. In the exit discharge, exterior stairway and/or outdoor stairway provisions may be applicable in assessing access from the exit to the public way. By their very name, "exterior exit stairways" must be part of the exit, not the exit discharge.
 
Upon leaving the building or the exit, the means of egress then consists of the exit discharge. In the exit discharge, exterior stairway and/or outdoor stairway provisions may be applicable in assessing access from the exit to the public way. By their very name, "exterior exit stairways" must be part of the exit, not the exit discharge.
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I agree with AegisFPE on this comment, however I don't believe that there are three distinct stairways. The defintion in 1002.1 sets the parameters when it's an exterior stairway. If it doesn't meet the definition, then it's an interior stairway and may have to meet the provisions for vertical exit enclosures. The provion for outdoor stairways is for water accumulation and has nothing to do with exit or exit discharge but is applicable to all exterior stairs, whether they are an element of a required means of egress or not.
 
Thanks, High Desert, I had missed the definition of "Stairway, Exterior" in 1002.1.

So the methodology for determining whether an "outside stair" is part of the "exit" vs. "exit discharge" is:

1. Determine whether the stair is part of the means of egress path-of-travel to the public right-of-way or safe dispersal area. If "yes" then go to #2.

2. Determine whether it meets the definition of "Stairway, Exterior" in 1002.1, especially looking for the yard, court, or public way. If "yes", then go to #3

3. Determine whether the stair still requires separation from the interior of the building via fire-resistive construction and/or opening protectives - - including examination of applicability of 1023. If the answer is "no" (no protection) then that's probably NOT an "exterior exit stairway" within the "exit system", and therefore it must be part of the "exit discharge" system.
 
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