Reduction In Calculated Occupant Load

[north star]

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I have a project where the calculated Occupant Load
is 454 occs. for one bldg.......Instructions have been given
to the RDP to reduce this calculated OL to 98 occs.

QUESTION # 1: Can calculated OL's be reduced by the AHJ ?
QUESTION # 2: If so, are there Codes that allow this ?....If
not, which sections of either the IBC or the IFC will prevent
this reduction "legally" ?.......I am using the `12 Codes.

Thanks for your input !


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[steveray]

Technically....Yes, but you would be out of your mind to quarter the OL IMO....

1004.1.2 Areas without fixed seating. The number of occupants
shall be computed at the rate of one occupant per unit of
area as prescribed in Table 1004.1.2. For areas without fixed
seating, the occupant load shall not be less than that number
determined by dividing the floor area under consideration by
the occupant load factor assigned to the function of the space
as set forth in Table 1004.1.2. Where an intended function is
not listed in Table 1004.1.2, the building official shall establish
a function based on a listed function that most nearly
resembles the intended function.
Exception: Where approved by the building official, the
actual number of occupants for whom each occupied
space, floor or building is designed, although less than
those determined by calculation, shall be permitted to be
used in the determination of the design occupant load.

 

[mtlogcabin]

What is the reason to reduce the OL and is it for all the OL driven code requirements or just a specific on or two.
I have never reduced the required OL numbers to reduce the number of exits of any other life safety code requirment
ventilation requirements, plumbing fixture counts to match state license occupant limitations on day cares, assisted living or other examples I have entertained and reduced the numbers accordingly

 

[fatboy]

I've used that section before.....just for minimal changes. We have many 100+ year old buildings that deep and narrow, that back in the day were mercantile or business uses, with only a single public exit, the second was usually in the back, through storage, or office areas. Now, many of them have converted to assembly uses, and the second exit is usually problematic. The OL might calc at 52, 55, 58, but realistically, they would have trouble even hitting that number. So I have allowed signage that restricts OL to 49, and allowed a single exit. I've never allowed more than calculated 59 to be reduced though.

I don't have any heartburn about it, typically it is a joint decision between the Fire Marshall, my Plans Examiner and me.

 

[north star]

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Thanks for the input so far !

This bldg. is a military facility......No reasons stated on the plans,
other than guidance was given by an individual to reduce it.

I am looking for code sections to refute the reduction......Simply
stating that the AHJ wants it this way [ IMO ] is not logical,
sound decision making or prudent.

The individual that requested the reduction has "in-roads" to
the decision makers.

I am still searching for code sections...

This will be a renovation of 2 existing Warehouses and adding the
B Occ. Group to it....A B, S-1 & an A-3.......Also, these military
facilities are intended to be a long term design [ 50+ years ],
so it very well could be that the 454 persons could utilize the facility
at one time.

I am still scratching my head on this one...

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[SCBO1]

Can you use the IEBC in anyway to reduce the OL?

 

[cda]

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Thanks for the input so far !

This bldg. is a military facility......No reasons stated on the plans,
other than guidance was given by an individual to reduce it.

I am looking for code sections to refute the reduction......Simply
stating that the AHJ wants it this way [ IMO ] is not logical,
sound decision making or prudent.

The individual that requested the reduction has "in-roads" to
the decision makers.

I am still searching for code sections...

This will be a renovation of 2 existing Warehouses and adding the
B Occ. Group to it....A B, S-1 & an A-3.......Also, these military
facilities are intended to be a long term design [ 50+ years ],
so it very well could be that the 454 persons could utilize the facility
at one time.

I am still scratching my head on this one...

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I take it fire sprinklers installed??

If so maybe one reason for reduction is reduce rated walls?

Or exiting?

 

[RLGA]

If the means of egress system has sufficient egress width for the higher occupant load, then I would have no problem with a lower occupant load—let them manage the maximum of 98 occupants. However, if it is intended for the means of egress to be based on the lower occupant load or elimination of sprinkler requirements due to occupant load, then I would have a problem, especially if I was the design professional. I would want it in writing that the lower occupant load was directed and that I would not be responsible for uses of the facility that exceed the designed occupant load (you know they will if the building can have a higher occupant load).

 

[steveray]

1004.1.2 Areas without fixed seating. The number of occupants
shall be computed at the rate of one occupant per unit of
area as prescribed in Table 1004.1.2. For areas without fixed
seating, the occupant load shall not be less than that number
determined by dividing the floor area under consideration by
the occupant load factor assigned to the function of the space
as set forth in Table 1004.1.2. Where an intended function is
not listed in Table 1004.1.2, the building official shall establish
a function based on a listed function that most nearly
resembles the intended function.
Exception: Where approved by the building official, the
actual number of occupants for whom each occupied
space, floor or building is designed, although less than
those determined by calculation, shall be permitted to be
used in the determination of the design occupant load.

 

[north star]

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Pcinspector1, Not sure......The IEBC doesn't appear anywhere in the
plans or Specs.

cda, Yes, the bldg. is planned to be fully sprinkled.

RLGA, Yes, the plans state that the individual DID request the lower
OL........Also, the calculated MOE is based upon the 98 occs.
I have no idea why this reduction has been requested.....The Bldg.
Official in this case is not aware of this reduction, yet!.....There
are too many variables at play for me to go in to detail about all
of this........My initial thoughts were to locate the Code Sections
first to present to the Code Official.

steveray, I believe that your listed Code Section provides the
strongest supporting [ Code ] language to refute the reduction
so far.

All good stuff, ...keep it coming !

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[jwilly3879]

See the thread titled "Community Hall" for a similar discussion. I was faced with the same type of problem.

 

[cda]

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Pcinspector1, Not sure......The IEBC doesn't appear anywhere in the
plans or Specs.

cda, Yes, the bldg. is planned to be fully sprinkled.

RLGA, Yes, the plans state that the individual DID request the lower
OL........Also, the calculated MOE is based upon the 98 occs.
I have no idea why this reduction has been requested.....The Bldg.
Official in this case is not aware of this reduction, yet!.....There
are too many variables at play for me to go in to detail about all
of this........My initial thoughts were to locate the Code Sections
first to present to the Code Official.

steveray, I believe that your listed Code Section provides the
strongest supporting [ Code ] language to refute the reduction
so far.

All good stuff, ...keep it coming !

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Is this on a federal base??

Or a city and lease space for feds??

 

[north star]

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Thanks **jwilly3879** for the input !

**cda**, ...Yes, this facility is on a large military training center.
Not sure if it is all federal......I think that it is a mix of state & federal.

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[cda]

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Thanks **jwilly3879** for the input !

**cda**, ...Yes, this facility is on a large military training center.
Not sure if it is all federal......I think that it is a mix of state & federal.

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Still can kind of do what they want.

Guess just write the violations and see where it goes.

 

[RLGA]

How many exits are provided out of the building? Do all the occupants have access to all of the available exits, or are some of those only for specific spaces?

 

[Yikes]

We used to request this exception all the time for gymnasiums at fitness centers.
The way the code is written, it assumes that the gym will be used like a high school multipurpose gym, where large assemblies will be held. But at a fitness center, the gym will only be used for a pickup basketball game. Even playing 2 simultaneous half court games with full teams, that's only 20 people.

 

[north star]

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In a preliminary review of the plans & Codes Analysis,
there appears to be a sufficient number of exit doors
for the facility......I haven't gotten far enough in to the
review to say for sure that this will be a fully sprinkled
facility.

As I mentioned earlier, these military facilities are
intended to be used on a long term basis, 50+ years.
And long term, the occupant load could change.....More
commands could occupy the building.

My heartburn with this is that there is a calculated Occ.
Load of 454, and one individual [ < --- not the BO ] has
given a directive to reduce the Occ. Load to only 98.
They have been doing this sort of thing for years.

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[cda]

Yep

But most federal buildings do have fire sprinkler systems.

I guess that is thier trade off

 

[RLGA]

As a retired Air Force officer, I know that there technically is no "building official" for military buildings on federal property--it is usually the base/post commander who has the authority over facilities on a military installation. If the project is a "Military Construction" (MILCON) project, then the U.S. Army Corps of Engineers (USACE) or Naval Facilities (NAVFAC) will be responsible for project management and will be the enforcers of the building code.

If you are the RDP for the project, I would just state your objections and reasons in writing for the record and do as they ask if they continue to insist on a reduction of the occupant load contrary to the IBC. However, the building may still comply with the higher occupant load even though a reduced occupant load is requested.

For example, a corridor is required to be no less than 44 inches wide. At 0.2 inches per occupant, a 44-inch-wide corridor can handle 220 occupants. Since one half of the occupant load will theoretically go in one direction and the other half in the other direction, the corridor can technically accommodate 440 occupants. If the corridor is a bit wider than that, all the much better. If there are three exit doors or two double-leaf exit doors, then you would have a total clear egress width of 99 inches and 138 inches, respectively. Again, at 0.2 inches per occupant, the 99 inches of egress width can accommodate 495 occupants and the 138 inches can accommodate 690 inches--more than the calculated occupant load.

The code minimums for egress components will provide a greater capacity than the requested occupant load, so you may be code compliant even if they don't realize it.