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» ICC Bulletin Board » Code Chat » Building and Residential Codes -- Non-Structural Issues » egress width AND travel distance (Page 1)

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Author Topic: egress width AND travel distance
LinnArchSJT
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Here's an interesting one...

I'm doing a preliminary review on an 360'x80' addition to a middle school. The "addition" is actually a new building connected to the existing school via a 6' wide link on all floors. The first floor is OK with egress but it is the second and third floors of the addition where it gets sticky...

There is a stairtower at either end of the new addition with an egress capacity of 300 per stair. Each floor has a calculated occupant load of 750. To get the additional 150 occupants out, the architect is counting on the link to the existing building. The egress capacity in the existing building is more than enough to handle that load, but here is my dilemma...

To use the link as required egress, the path of travel would exceed 250' BUT any occupants in the addition are still within the required 250' of an exit... those exists just aren't big enough to meet the egress capacity requirements.

Basically, the architect has written a detailed analysis stating that A) The building meets all egress capacity requirements (which it does) and B) any point in the building is within 250' of an exit (which it is). The grey area is that the 150 occupants that are above the required load for the stairtower are more than 250' away from their "dedicated" exit, but within 250' of the nearest exit (which can't handle their load). Can this issue be separated as the architect has done, or do all occupants need to be within 250' of an exit that can handle the load?

Sorry for the long post, but I don't know how to explain it in less words. This should be an interesting discussion.

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cda
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What code and edtion are you under???


I hope 150 people know to go the other way.

are you saying in the exiting building the additional load if allowed the exiting cannot handle it either??

If it could can you do a horizontal exit?? as long as all other provisions for horzintal are
met??
Also, if under the I code the second exit has to handle fifty per cent or 375 from the third floor, so it looks like there are mulitple problems.

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LinnArchSJT
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Sorry, I was trying to be concise and left out the code... it'll be under IBC 2003.

I brought up the horizontal exit idea with them and it would not work in terms of function and security as far as the school goes.

The existing building can handle the load, but anyone exiting thru the existing building from the addition would be traveling in excess of 250'.

I guess another way of putting it is that 150 people per floor in the new addition will be going to an exit in which the capacity cannot support them or is over 250' away. But if you look at the big picture, which the architect is doing, the entire building (exist+addition) meets egress capacity requirements, and every location in the building is within 250' of an exit.

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Walt
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All the occupants need to be within travel distance of an (one) approved exit. Providing you are meeting other requirements to consider the facility as one building, whether IBC or IEBC, there is no problem.
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AegisFPE
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I agree with Walt. You are describing that they meet the required number of exits and the required travel distance (albeit independently, not simultaneously).

Consider a 400-foot long hypothetical office building with one exit at each end, and a conference room requiring two exits at one end.

The conference room occupants have access to the required number of exits, and are within the required travel distance of an exit. The code does not specifically require all required exits to be within the specified travel distance.

As the intent of multiple exits, in part, is to provide for evacuation in the event 1 exit is blocked, it is reasonable to anticipate that where 3 exits are required, only 2 would be used by the occupants.

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cda
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I think I agree with you and the stairs need to be upgraded to handle the load.

normaly you do not want people going back into the building

if the end of the corridor leading into the exiting building is on fire or full of smoke the one stair is not designed to handle the load.

and once again the second exit is suppose to handle half the occupant load.


AegisFPE
I would agree with you if the required exit width is there, in the set up given the exit width is not provided in the first place.


" I brought up the horizontal exit idea with them and it would not work in terms of function and security as far as the school goes. "

Sounds like they need to rethink the entire set up.

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AegisFPE
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cda:

The information provided in the "set up" of the original poster includes 2 points which appear to indicate that the required egress width is present.

A) The building meets all egress capacity requirements (which it does)

B) any point in the building is within 250' of an exit (which it is)

My understanding is that the horizontal exit approach was in order to satisfy the travel distance within the new addition. We are not told that the "link" has insufficient exit capacity, just that the remaining occupants for which stair width is not provided would traverse this path. Most school corridors are relatively wide.

An issue that is unclear without plans, is the distribution of exits such that a single event does not compromise both the link as well as a stair from the new addition.

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cda
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AegisFPE


I am not a stair expert but it sounds like there is not enought stair width to begin with:

There is a stairtower at either end of the new addition with an egress capacity of 300 per stair. Each floor has a calculated occupant load of 750

side note: I like your cities appraoch to house sprinkler systems

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AegisFPE
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What we are not specifically told is that the total exit capacity of the stairs in the existing building can accommodate 1,000 occupants per floor, and that the occupant load served is only 850 per floor, such that there is "room" for 150 more occupants in the existing egress system. (I made these numbers up for purposes of discussion.)

It sounds like the completed project is considered one building, such that an occupant in the existing corridor and an occupant in the corridor in the new addition would be in the same corridor. Thus, they are not leaving a building/re-entering a building - there just happens to be a spot in the corridor that has no rooms on either side (where the "link" occurs).

Therefore, my understanding is that if we look at the whole building as a single structure, as if it had not been built in phases, we would see that there are 1,750 occupants, and exit width is provided for 1,750 occupants, and all portions of the egress system satisfy common path of travel for access to 2 exits, and travel distance to 1 exit.

P.S. I'll pass your compliment onto the city, as opposed to "my" city!

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cda
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AegisFPE
good answer good answer

I guess with out a full set of plans hard to say right or wrong

just does not sound right the salmon smells

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LinnArchSJT
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This IS a tough one to describe without drawings, but I'll take another stab...

I'll concentrate on just one floor to make it easier. The new addition has a calculated occupant load of 750 and a stairtower on either end with an egress width that can handle 300 occupants each. The addition is 360' long, so every spot in the addition is within 250' of an exit.

The existing portion of the building (exclusive of the addition) has a calculated occupant load of 2,000 and multiple stairtowers with a total egress capacity of 2,200. All areas of the existing building are within 250' of an exit.

What the architect is saying is, "I have a total occupant load of 2,750 and total egress capacity for 2,800. All areas are within 250' of an exit... I comply."

The issue I see for the addition is if it is to meet the required egress width, 150 people need to exit through the link, into the existing building. Yes, the existing building can handle the capacity, but those 150 will need to travel more than 250' to find an exit that has an egress width to support them, even though there is another exit down the hall within 250'... it just doesn't have the egress width to support them.

Is that any better?

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cda
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is the new additon connected directly to the existing building?? or is there a walkway between the buildings put there for some other code reason or so other code requirements would not kick in???

I keep going back to if you are at the far end or in a room 250 feet from the far end of the new additon and the corridor is blocked leading to the existing building are they trying to dump more than 300 people into the stairway that is not designed to handle it???

And once again not a stair expert but play one on tv How does the I code deal with upper floors dumping people into a stairway that other floors also have to use??? like in your set up the 3rd floor 750 people is using the same stair as the 2nd floor 750 people?????

Now maybe calculate the occupant load for the far end from 250 feet to the stairwell and if it is 300 and under good see his point.

Also are they meeting the fifty per cent 1005.1???

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NJFireMarshal(Ret)
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LinnArchSJT,

The first paragraph in your last description indicates the exits provided in the addition cannot handle the occupant load. That does not comply with the code for egress capacity.

The last paragraph of that description indicates that becuase the new addition does not have enough egress capacity 150 of the occupants may have to exit through the existing building and in doing so the travel distance will exceed the 250 feet maximum. That does not comply with the code for travel distance.

Have the architect provide an egress path analysis that show the intended path of travel for each area/occupant.

The analysis will visually depict the problem because it will either show that too many occupants are going to the exits in the addition, or it will show that 150 of the occupants are traveling too far.

When egress is designed/reviewed each room or space is analyzed along with the building as a whole for capacity, travel distance, common path of travel, etc. The individual rooms and spaces and the building as a whole must meet the code requirements. The designer is only looking at the building as a whole and is missing the room and space analysis portion.

The egress path analysis will provide the needed detail of the problem because it will show the intended path of travel, the number of occupants at each point along the path, the travel distance along each path and the increasing number of occupants along the path as you get closer to the intended exit.

--------------------
Borrowed comment: "Telling me your design meets the minimum requirements of the code just means it's one violation away from being illegal!"

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permitguy
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It seems like this is getting severely over-complicated.

As Walt pointed out, travel distance is measured to an exit, not every exit. Therefore they meet the required travel distance.

The contingencies for loss of an exit are already in the code. There is no reason to play out all the "what if" scenarios. If you did that, every exit would be required to supply the necessary width for the entire occupant load of the space. This is clearly not the intent of the code (1005.1).

Assuming the architects math is correct, this sounds perfectly compliant.

[ 03-02-2007, 08:46 AM: Message edited by: permitguy ]

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NJFireMarshal(Ret)
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Sorry permit guy, I disagree partially.

I agree you don't have to play out the 'what if' scenarios. In designing the egress components it is correct to assume they are all available when needed. That is not disputed in the description of the problem.

However, the 250 travel distance based upon the nearest exit being available has to take you to an exit that has the capacity to let you egress.

Based upon the description provided, the 'nearest exit path' in the addition indicates a shortfall of 150 occupants.

The code does not permit that.

Serving the addition by using a path through the existing portion of the building is also permissable to accomodate the 150 occupants in question, but the travel path must meet the maximum travel distance which the description indicates it does not.

Lets look at this in a more simple fashion.

The addition is the focal point of the review. The exits shown cannot handle the occupant load. So you ask the designer to indicate where the extra 150 people go to get out as required by the code.

The designer responds by indicating a path through the existing building which is allowed, but that path is longer than the code allows for the 150 occupants in question.

The code does not permit that. Each occupant is required to reach an exit of sufficient capacity within the maximum travel distance allowed assuming all exits are available when needed.
The design in the description does not do that.

--------------------
Borrowed comment: "Telling me your design meets the minimum requirements of the code just means it's one violation away from being illegal!"

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LinnArchSJT
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I'm thinking along the same lines as NJFireMarshal.

If an egress plan is drawn up, strictly adhering to egress width requirements, it will show 150 people in the addition travelling a distance greater than 250' to get to the nearest exit that can handle their capacity.

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jiano
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quote:
it will show 150 people in the addition travelling a distance greater than 250' to get to the nearest exit that can handle their capacity.
But does the code require that travel distance be tested this way? 2006 IBC says "measured...to an exit along the natural and unobstructed path". The travel distance section makes no reference to the capacity of individual exits.

I can see the logic in the argument. And if I were designing this building, I would rather meet this test than not. But is this a code requirement?

[ 03-02-2007, 10:07 AM: Message edited by: jiano ]

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jim baird
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Is the added wing, with its 750 occupant load, required to have three exits?

If so, then the exit out through the "connector" to existing building exits does not qualify as a third exit because it is too far away.

--------------------
IRC Combination, ICC Commercial Building, ICC Plans Examiner, SBCCI Housing Rehab

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NJFireMarshal(Ret)
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quote:
-------------------------------------------------
But does the code require that travel distance be tested this way? 2006 IBC says "measured...to an exit along the natural and unobstructed path". The travel distance section makes no reference to the capacity of individual exits.
-------------------------------------------------


From the 2003 IBC Commentary:

"The length of travel, as measured from the most remote point within a structure to an exit, is limited to restrict the amount of time that the occupant is exposed to a potential fire condition"

What good is there in making sure the travel distance meets the code if you can't get through the exit because it is too small to begin with?

All the pieces have to work together to have a successful outcome, i.e., a timely egress from the space and/or building. The code is written as a whole document to be appled as a whole, not line by line.

--------------------
Borrowed comment: "Telling me your design meets the minimum requirements of the code just means it's one violation away from being illegal!"

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AegisFPE
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I almost hear the discussion leading to "no exits can be greater than 250 feet apart."

This is based on:
- occupants on an upper floor are required to be provided with 2 exits.
- travel distance limitations must be demonstrated to be provided to required exits.

Therefore, an occupant at one exit would be required to be able to get to the second exit by traveling no more than 250 feet. I disagree with this interpretation.

The very first line of the commentary (1015.1) states, "The length of travel, as measured from the most remote point within a structure to AN exit..." (emphasis added).

The first line of the 2nd paragraph, "The travel distance is measured from each and every occupiable point on the floor to THE CLOSEST exit." (emphasis added).

IBC 1014.2.2 states, "exit access doorways shall be arranged a reasonable distance apart so that if one becomes blocked, the others will be available."

The code in 1014.2.2 is specifically anticipating that where multiple exits are provided, occupants will not be using 1 of the exits. Does that mean we need to make the available egress widths larger so that 100% of the occupant load can be accommodated if one exit is blocked? No. Does that mean we should make sure that at least 2 exits are within the travel distance of every occupiable location? No.

This is a perfect example of a safety factor that is built-in to the code.

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cda
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Do you have to design the stair width by just one floor or is it the addition of all the floors???

for instance in this case do you ad the 2nd and 3rd floor occupant load say 350 3rd floor + 350 2nd floor = 700 and divide by the stair factor to get the required stair width??????

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jiano
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quote:
...just one floor or is it the addition of all the floors???
Just one floor: IBC 2006 1004.4

[ 03-02-2007, 11:35 AM: Message edited by: jiano ]

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permitguy
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I agree with Aegis. It has never been a requirement for the entire required egress width to be placed within the required travel distance. The code says to measure travel distance to "an exit." What if everyone goes running through the corridor and ignores the new exits? What if everyone runs to one of the new stair towers and ignores the other? You can "what if" any egress scenario to death, it won't change the minimum requirements.
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NJFireMarshal(Ret)
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Nobody has played the 'what if' scenarios if you read the description of the problem presented by the poster or mine.

And nobody has called for increasing egress widths just in case one or more are unavailable.


I made my posts very clear that the comments are based upon ALL exits being available at the time they are needed.

The description is clear. The new addition holds 750 people, the exits that are designed into the new addition have a capcity of 300 each for a total of 600 people.

So, tell me where do the other 150 people go? The code requires that the exit capacity be provided to handle the occupant load for the area served.

If you tell me they will egress through the existing building I accept that. The code allows that. But they must get to that exit within 250 feet.

If you give me a plan that indicates area X is within 250 feet of the exit so you meet the travel distance requirement, the exit must have capacity for area X for the egress system to work.

The description provide does not do that.

You cannot sewriously argue that those 150 people are okay because an exit they cannot get through is within the required travel distance.

If this was a new building, not an addition, you would reject the plans and tell them to either increase the capacity of the two exits or install a third one within the required travel distance for the additional 150 occupants. The fact that this is an addition does not modify the basic requirement that exits with the required capacity be within the required travel distance.


And since we do not increase the capacity of the stairs based upon serving multiple floors with the exception of converging floor levels, the comment about safety factors goes out the window. We size stairs in the code as if only a single floor is using the stairs at one time and we know that is not the case in an emergency.

--------------------
Borrowed comment: "Telling me your design meets the minimum requirements of the code just means it's one violation away from being illegal!"

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zigmark
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If I am not mistaken this new and existing are considered two separate buildings? If that is accurate then there is not an issue unless traversing the portion between the new and the existing exceeds the travel distance. If this distance is within the allowable then they should comply because they have exited the building and their allowable travel distance starts over for the "new" building, and potentially a new occupancy, they have entered. This is a question I have posed several times at different seminars put on by ICC in our area. The concensus I have been given by the three instructors I asked was that passing through a fire separation was considered exiting the building, however it may be only to enter another building which may have more or less restrictive rules of its own. The only thing I have not mentioned in this scenario is that the increased load on the existing would have to be looked at to ensure the existing exiting was not overburdened. ZIG

[ 03-02-2007, 02:24 PM: Message edited by: zigmark ]

--------------------
'06 IBC,IRC,IMC,IFC,IFGC,UPC all with Washington State ammendments, Now we're having fun!

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permitguy
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All 750 of those people are within 250' of an exit. That's the end of it as far as travel distance goes. All 750 of them DO NOT have to be within 250' of the total required egress width at all times, as is being suggested. The other 150 may travel further than 250', but they were within 250' when they started, and that is all that matters when considering travel distance.
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NJFireMarshal(Ret)
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Permitguy,

Quote:
----------------------------------------------
The other 150 may travel further than 250', but they were within 250' when they started, and that is all that matters when considering travel distance.
-------------------------------------------

If that is what you believe the code intends and that it makes sense, all I can say is good luck. I'm out of responses for you.


Zigmark,

Look at the third post. The concept of a horizontal exit was looked at and determined not to be feasable. That's one of the reasons there is a problem.

But you are correct, had it been available the distance to the exit on the other side wouldn't have been an issue.

--------------------
Borrowed comment: "Telling me your design meets the minimum requirements of the code just means it's one violation away from being illegal!"

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TJacobs
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I agree with NJFireMarshal's position.

quote:
Basically, the architect has written a detailed analysis stating that A) The building meets all egress capacity requirements (which it does) and B) any point in the building is within 250' of an exit (which it is). The grey area is that the 150 occupants that are above the required load for the stairtower are more than 250' away from their "dedicated" exit, but within 250' of the nearest exit (which can't handle their load). Can this issue be separated as the architect has done, or do all occupants need to be within 250' of an exit that can handle the load?
If you are going to claim an exit is within 250' of X number of occupants, then that stair had better be able to handle the capacity you are sending it.

1005.1 "...Multiple means of egress shall be sized such that the loss of any any one means of egress shall not reduce the available capacity to less than 50% of the required capacity."

If he is short already in the new addition, will he comply with the above?

--------------------
Jake

Sometimes a great deal of effort is expended to avoid the inevitable.

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jiano
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How about this: I have a hypothetical building that is 300 feet or longer (more than the permitted travel distance). Everything else is like the project being discussed:

It has an occupant load of 750.
It has 2 exits at one end, with a capacity of 300 each, and a third exit at the opposite end with a capacity of 150.
The maximum travel distance is 250'.

Travel distance limits are met: Each occupant is within 250' of an exit. However, assume occupants are evenly distributed throughout the space and do an egress path analysis. Because one end of the building has an egress capacity of only 150, some occupants may travel more than 250' to the exit identified in the path analysis.

Is this legal?

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AegisFPE
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As I have mentioned before, the code anticipates exits to be blocked, which is why multiple exits are required, and why the egress widths provided must be balanced, and why the exits must be separated appropriately.

It is legal in my book Jiano (you'll notice my hypothetical 400-foot long building in a previous response).

Most egress plans submitted by designers simply indicate the total occupant load, and total egress capacity - the subject building appears to pass.

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NJFireMarshal(Ret)
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jiano's example is not compliant with the code.

You cannot approve a design that requires occupants to exceed the travel distance.

The exit must have the capacity for the cumulative load of occupants the design indicates will use that path of travel.

A good example of what the code intends can be found by looking at Section 1004.1.3 of the 2003 IBC.

"1004.1.3 Number by combination. Where occupants from accessory spaces egress through a primary area, the calculated occupant load for the primary space shall include the total occupant load of the primary space plus the number of occupants egressing through it from the accessory space."

From the IBC Commentary: "This section provides a method by which the occupant load of adjacent areas of a building is calculated. The resulting occupant load is what must be considered. For example, the means of egress from a lobby must be sized for the cumulative occupant load of the adjacent office spaces if the occupants must travel through the lobby to reach an exit. Likewise, if an adjacent room has an egress route independent of the lobby, the occupant load of that room would not be combined with the occupant loads of the other rooms that pass through that lobby. If a portion of the adjacent room’s occupant load is to travel through the lobby, only that portion would be combined with the lobby occupant load for the design of the means of egress from the lobby (see Figure 1004.1.3). This is particularly important in determining the capacity and the number of means of egress."

There is also a Figure 1004.1.3 that gives a visual depiction of adding up the occupants as you travel along the path to make sure the exit door can handle the accumulative load.


An 'egress path analysis' does what is intended by 1004.1.3, it depicts the path of travel from each space to the exit, adding up the number of occupants as you go along. When you get to the exit it must have the capacity for the total number of occupants shown to use that exit as the primary exit based upon travel distance.

The bare bones egress plan AegisFPE refers to typically does not show compliance with the code other than for very simple and usually small projects.

The code does not require or encourage blindly distributing egress widths or exits (capacity) equally balanced. It requires a more in depth analysis to ensure that the occupants can get to the primary exit within the travel distance allowed and that when they get there the exit has the necessary capacity. The capcity along that path may have to be increased as the number of occupants using the path is increased. (for asthetic purposes the width typically is based upon the larger number at the cumulative end).

The code does not size exits based upon blockage as AegisFPE indicates. The code specifies a minimum number based upon the occupant load to provide for a secondary path (see Sections 1014.1 and 1018.1 of the 2003 IBC), but DOES NOT provide for any increase in the capacity of the exits due to the possibility of a blocked exit. Capacity is only based upon primary paths of travel. (It's a minimum code)

All travel distance and capacity requirements are based upon all primary exits paths being available.

The code language cannot be sliced and diced to make it fit the situation. The code is developed as a whole and is applied as a whole. If you take the time to sit through the code hearing process you will routinely hear questions, comments and testimony concerning a proposed change's effect on a different section of the code. And if the proposal causes a conflict with or otherwise negatively effects another section of the code or the end result the code intended it is routinely voted down.

The overriding concept is that each occupant be provided with a primary exit that gets them out of the room, space or floor within the travel distance specified. To do that the exit is not just within the required distance, it also has the capcity for the occupant to actually egress through it.

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Borrowed comment: "Telling me your design meets the minimum requirements of the code just means it's one violation away from being illegal!"

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permitguy
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I hate to just give up, so I'll try one last time.

quote:
The code requires that the exit capacity be provided to handle the occupant load for the area served.
This statement is absolutely correct.

Now, please tell me where the code says "the total exit capacity must be within the required travel distance." The code doesn't say this. In fact, it doesn't even suggest it. The code says travel distance is measured to an exit. It does not require you to measure to multiple exits, then add up the total capacity of those exits and make sure they meet the required total exit capacity.

With respect, applying the code as it is written is not "slicing and dicing" code language. Applying it as a whole means making sure every section is complied with. In jiano's example, every section is complied with.

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NJFireMarshal(Ret)
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Permitguy,

When you assess travel distance, it is to an exit you can actually get out of. That is an extremely basic egress concept. The need to actually pass through the exit to the outside.

You cannot use an exit for travel distance if the occupant has no expectation to fit through it. That would be no different than sending them to a primary exit within the required travel distance and then keeping the exit locked preventing them from using it.

jiano's example clearly explains that some of the occupants wil have to travel more than the required travel distance to exit the building because the closest exit does not have the capacity to handle the intended load. That is not permitted.

In my last post I intentionally cut and paste the actual code language at 1004.1.3 and the commentary for that code language. I pointed out there is even a figure representing that explanation.

That code language and the nice picture example that is provided verifies what I have been posting, i.e., you add up the occupants traveling to the exit (travel paths) and the exit is required to be sized to handle that CUMULATIVE occupant load.

Take the time to look at the commentary and the picture, and if you still want to disagree, post an explanation of what you think 1004.1.3 really means.

I know this much. If I am a designer and I determine what exit is the one that is within the 250 feet in this case. And then I define the path of travel to that exit and I place the exit signs leading you to that exit along that path of travel, (exit signs - don't forget those, another part of the complete package when applying the code), when you get to the exit I designated for you and led you too, I am pretty sure there is going to be a bunch of liabilty to go around when can't get through the exit in time because of the backup caused by the lack of capacity I designed into your designated primary exit. (Including for the code official that allowed it).

And I am also pretty sure the weak defense that "Oh no, that may have been the one within 250 feet, but we expected you to know you had to go to a different one farther away" is not going to pass scrutiny.

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Borrowed comment: "Telling me your design meets the minimum requirements of the code just means it's one violation away from being illegal!"

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permitguy
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Consider the number of ways we have to require additional exiting. Common path of travel, travel distance, occupant load, inadequate separation, and egress width all come to mind. These are independent of each other. Any of these could trigger requirements for additional exiting on their own. In my opinion, the cumulative effect of individual compliance with all of these requirements is enough to make a building safe. I still think you have read more into travel distance than what it intends. Perhaps a proposal to change the language for clarity is in order.

We obviously won't change each other's minds on this. Let's just remember that we're on the same side. I don't want middle school kids to be unsafe, I just don't agree that they would be unsafe in the situation described in the OP.

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NJFireMarshal(Ret)
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Your last post sums up our overall difference on the concept of egress compliance fairly well.

You believe that the various egress requirements are independent of each other and that individual compliance has a cumulative outcome that meets the intent of the code.

I believe that the various egress requirements are dependent upon each other and need to be designed/assessed collectively to meet the itent of the code.

We'll have to agree to disagree.

Bob

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Borrowed comment: "Telling me your design meets the minimum requirements of the code just means it's one violation away from being illegal!"

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Old n Broken
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Right in the first page of the Code it talks about intent. I think we can all agree that the intent of the Code is to provide a safe building. It doesn’t matter if some yo-yo architect has found a loophole in the Code – If this new addition design doesn’t comply with the spirit and intent of the Code it should be changed to do so.

We are talking the safety of people (and children at that). If anybody was injured because of a failure of the egress system I doubt anybody would be satisfied that this building squeezed through plan check because of a quirk of the Code.

On a lighter note. I am all for intellectual exercises. Throw me a soduku and I am all over it. This is one of the more interesting threads lately.

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cda
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jiano
1004.4 IBC 2006
Thank you, the sections is not clear and the commentary seems to clear it up a little.

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LinnArchSJT
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quote:
When you assess travel distance, it is to an exit you can actually get out of. That is an extremely basic egress concept. The need to actually pass through the exit to the outside.
The problem is that it seems so basic to you and I yet there is no "drop-dead" specific clarification of it in IBC 03. I'm going to stand my ground on the issue, but I'd prefer having a loaded gun.
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cda
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I think with out seeing the plans the answer can go either way, but after all the discussion it seems that the set up is ok. In that not all exits in a building are designed to handle the entire occpant load of a building. The required exit width is spread around the building, and as long as at any point in the building an exit is within travel distance and the additonal exits besides the main exit can handle fifty per cent it seems that the building meets code.
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AegisFPE
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Linn: I understand your desire to know whether the answer is yes or no. Unfortunately, this is one of many areas of the code that is clearly not black or white, and for which the official is left to make their own interpretation.

I would not characterize the architect's analysis as following a "loophole" in the code (I would not call code requirements loopholes). Multiple members here have stated legitimate reasons for their agreement with the architects more global analysis of the project.

Perhaps as far as your review is concerned, the issue could be addressed with regard to separation of exits, in accordance with 1014.2.2. This section is rare instance where our prescriptive code provides performance criteria. It may be appropriate to ensure that a single event does not block multiple required exits.

However, in light of this performance criteria, the prescriptive requirements appear to inherently provide a factor of safety. This is because the performance element does not say that the other provisions of Chapter 10 must be satisfied when the nearest exit is blocked. Therefore, as I've mentioned before, my understanding of this code requirement is that the egress width need not be increased, and the travel distance need not be decreased, and the common path of travel need not be satisfied, when evaluating the building using this performance criteria under a "blocked exit scenario."

There should not be a turnstile at the top of the stairs that locks out the last 150 people, nor a posted sign with the occupant capacity of a stair - or a guard to enforce it, this is because the code apparently anticipates that more occupants will be able to use the stair than as prescribed by the design criteria.

The situation is similar to a simplified conference room arrangement where 2 exits are required, again anticipating that one could be blocked. This does not mean that we increase the door width to satisfy 100% of the occupants through each door or re-evaluate the common path of travel.

Therefore, in your case, if the exit stair in the addition that is most remote to the existing building were blocked, the occupants for whom that stair was designed would travel to the other end of the addition (or further); either of which is not specifically "designed" to satisfy the travel distance or width for occupants in the other end of the building. And, this is all happening when the code is anticipating the presence of an emergency event.

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Builder bob
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I just hope that it isn't my kid that is being left out in the cold when the kismee hits the fan. All children and more importantly, all people deserve a chance to escape if some event triggers a reason for leaving a building. (Can you say Columbine High?) While the argument can be made that it meets code....does it meet the intent of the code. I am going to side with the RetNJMArshal on this one......25 years of fire service does have a tendency to let you see the more important side of code enforcement (people safety) than monetary gain (for cutting construction cost).


ALSO ... In the event of an emergency is a condition going to be created that will make the existing means of egress non-compliant or useless(i.e. overcrowding, blocking of the means of egress, trampling of people, etc.)


(Boy I hate my big fingers - spelling errors corrected)

[ 03-06-2007, 07:23 AM: Message edited by: Builder bob ]

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Can you build to minimum standards? FWIW - MCP, CBO, CPE, CI, CFPE, ASCET
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Shim
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It's easy to see both sides of this one. Sounds like a perfect time to break out the good ol' NFPA 101 handbook.

Now where did I put that thing?.....

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bhenry
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It would be interesting to hear the ICC's take on this. Linn, why not get a verbal opinion from them...everyone else has chimed in. I personally agree with NJ.

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"WHERE you live should no longer determine WHETHER you live" Bono

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TJacobs
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It would be interesting to see the floor plan...

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LinnArchSJT
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quote:
It would be interesting to hear the ICC's take on this. Linn, why not get a verbal opinion from them...everyone else has chimed in.
The architect is soliciting their opinion. I will share it with everyone when I receive it.

Additionally, the local Fire Marshal has jumped into the fray as well. Since the school is required to submit emergency egress and fire safety plans, per the fire code, those plans will be showing the 150 occupants traveling over 250' to their "first" means of egress. I'll accept the ICC interpretation, should it side with the architect, but I'm not so sure the Fire Marshal will... especially since his grandson goes to the school.

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dat
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Of the hundreds of topics I've read on this chat this one may take the proverbial cake. The architect must be half mad by now, if not totally crazed. If we imagine the old French Foreign Legion films, those who think that the described scenario is non-compliant would be stripped of your uniform; drummed out of the of the fort and left on your own in the desert.
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jiano
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quote:
It doesn’t matter if some yo-yo architect has found a loophole in the Code
quote:
The architect must be half mad by now, if not totally crazed.
At the risk of sounding defensive I feel compelled to stick up for my profession: IMHO you guys should stop ragging on the architect. The extent of the debate here seems to suggest that the code is less than crystal clear on the question posed. Personally, I don't disagree with NJFireMarshal's intent. But, if the exit stairs must be enlarged and more of the owner's money spent, the owner deserves to know if it's a code requirement or not.

The AHJ gets to make the final call in any case. Why resort to name calling?

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FredK
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"Can this issue be separated as the architect has done, or do all occupants need to be within 250' of an exit that can handle the load."

I would have asked to see the exit plan. That would show the number of occupants and how they're going to be exiting.

Code requires travel distance to be measured from the most remote to the closest exit. Which this plan sounds like it does. Even if some must go to another exit that distance to a second or third exit is not regulated.

It sounds like the problem is in the "stair tower" design at this time. It might not meet the Means of Egress Continuity 1003.6 as the egress width is reduced so that the design occupant load would not be served.

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rvsarch
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I am an Architect working on this specific project. I would not be making this argument unless I thought it was first and foremost safe and secondly, absolutely met the minimum standard set by code. We are considering the addition and the existing building as one and are fully sprinklering and adding fireproofing to all of the steel in the completed school to create a single building of type IIA classification. There are two exits in the addition and three additional exits in the existing building. In all cases, every spot in the project is within 250 feet of an exit. The third floor is the worst case. We have a calculated load of 1,060 and an exit capacity of 1,500. The exits at either end of the addition each have a capacity of 300 and the calculated load for the third floor of the addition is 750. If you did look at the stairs as being unable to handle more than 300 and therefore unavailable, which I do not think is the intent of the code, the 150 people in the addition that have more than 300 people ahead of them to either new stair are all within 250 of both new stairs. They also have a travel distance of about 300 feet to a third available exit in the existing building in the event that neither of the two new exits is available. It is my understanding that the 250 foot requirement only applies to the primary exit. These 150 occupants only need to exceed 250 feet when traveling to a third available exit. Using the code, we have calculated an occupant load for this building of over 5,000, even though the school has only 1,100 students, faculty and administrators. I am confident we are exiting the calculated number of occupants in a way that meets code requirements. It is hard to imagine the gym, auditorium, cafeteria and every single classroom filled to capacity at the same time or the school population ever reaching more than 2,000. In my opinion, there is a huge factor of safety built into the code when determining the occupant load for a school. In this project, it is not possible to load all of the exits in a way that is perfectly balanced, but we seem to be reasonably balanced and have kept alternative exit routes relatively short. If the code does require calculating the number of occupants between every room and a required means of egress and then counting out that means of egress after it reaches the calculated capacity, I have been unable to find it spelled out anywhere.
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Builder bob
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rvsarch....First of all, thanks for placing the scenario on the table for discussion
Second of all, I appreciate your due diligence to ensure it meets the requirements of the code for safety.


I can see both sides of this discussion, but I would hate to have an issue that places the possibility of inadequate means of egress in a design.
Does the design meet code? yes
Does it meet the intent of the code? no.

Are you sure that the minimum is what you want to design to and fight the position of in a court of law?

That is the question that you and a jury of 12 would have to decide.

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Can you build to minimum standards? FWIW - MCP, CBO, CPE, CI, CFPE, ASCET
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