• Welcome to The Building Code Forum

    Your premier resource for building code knowledge.

    This forum remains free to the public thanks to the generous support of our Sawhorse Members and Corporate Sponsors. Their contributions help keep this community thriving and accessible.

    Want enhanced access to expert discussions and exclusive features? Learn more about the benefits here.

    Ready to upgrade? Log in and upgrade now.

Rounding Up or Rounding Down...

Glennman CBO

Silver Member
Joined
Oct 20, 2009
Messages
441
I'll try this again. My post didn't post the 1st try.

2006 IBC, A-3 occupancy.

We all are familiar with the bench seating calculation of 18" per person where there are no dividers. I have 14 benches at 128" each. That totals 7.11 people. The .11 translates into 2".

Per section 1025.15 "Where bench seating is used, the number of persons shall be based on one person for every

18" of length of the bench".

In a rounding up scenario, one would add a person for the 2".

How can 2" be used for one person when the code specifically states that the number of persons shall be based on 18" of length per person?

Thanks all.
 
As we are getting fatter and fatter, there are not many 18" butts left in the US. I would use 7 persons per bench.
 
Are they preschoolers? or sumo wrestlers at this A3?

My inlaws need the exit width widened! "Salad bar! are you kidin"
 
I can assure you that wouldn't work at the "Big House" in Ann Arbor. When everyone else gets up to cheer, I stay seated and expand to my comfort zone :) and just look at the others with my arms out (oh well) :)

Always round down also!
 
Most people that I've discussed this issue with agreed that it would be acceptable to round down, but only due to the small fraction that is left for a "person". However, I find that most people believe that rounding up is a rule of thumb sanctioned by the code. I recall reading in the "Plan Review Manual" based on the '03 IBC where the author believed that rounding down in all cases was the correct method of computing occupant load. His reasoning was that if the load is based on a square ft figure assigned to a person (or in the case above, 18" per person), that to add a person in rounding up is going beyond that sq ft figure minimum that the code assigns for that person.

What I hear alot is that "more restrictive" governs. While this is true, it may be more restrictive to add these individuals while rounding up in the sense that it might kick in exit widths, panic hardware, etc, but it can also be "more restrictive" to round down, reducing number of people allowed to occupy the space.

I see rounding down with respect to occupant loads as being true to per person numbers in the code.
 
I seem to remember that the reason for the language change to the 2006 IBC (and maybe goes back to 2003) of "less than 50" and "50 or more" persons or occupants was to take away any rounding. If the calc comes out to 49.25 occupants then there are less than 50. If the calc is 50.01, then there are more than 50. No rounding required.

Getting back to the original post and 88twin's post, the question of rounding up or down is not that important. You can have more or less persons in a bench, despite obesity, there is also an anorexia problem. The bench seating is only part of the required set of calculations in an A-3 occupancy. There may be speakers, pastors, assistants, security and standing room. Whether there are 99 or 100 occupants in the benches, they require the same egress, plumbing, and other code requirements. It only gets sticky, where this situation puts you at limits, like number of exits, and plumbing fixtures. That's where you need to make your best judgment.

ps: I would round down in this case, I hate sitting next to bloody stumps.
 
i didn't look at A-3. the root of the OP was occupant load for bench seating.

doesn't matter what the occupancy class is bench seating is bench seating.

used to determine occupant load for egress purposes consistent with sec. 1004.7 fixed seating.

why 18"? is that average? have you sat in coach on an airline lately?

18" may be what i get, but it aint what i want

and why does every airplane have to have a crying baby? code requirement?
 
I round up (old IBCO habit). I want to check for the other things, exits, plumbing etc... that come with that number. Heck if we're trying to stay under a number for sprinklers, plumbing etc.... then take out one bench or but if you're that close why not get the sprinklers, plumbing etc.

Worse ofenders are IMHO the 30-60+ church groups designing a place for 400-1000 and complaining about what they have to do. Not only for me but planning for parking, etc....

Just my thought.
 
To round down would appear prejudicial to me, it would have the affect of excluding short and half a$$ people. In order to provide equality I always round up.
 
Round up for the exiting requirements; actual seating will be based on how many people you can exit ... if you use 18" (and since most of us can't fit into 18" anymore).. your actual occupancy will never exceed the number you can actually exit from the venue.
 
The new 2009 LSC addresses this finally and provides code language that supports standard rounding.

When the .5 shows up, I still question rounding in the bench seating situation, although I know of some folks that the half A** count would work.
 
Ignore the LSC unless you are required by law to enforce it..

You need to have exits to get everyone out of the building.. that's what 18" is for .. it's an exiting standard...

I could bring 15 8 year olds to the game and have a baby with me... behind me, the Biggest Losers might be sitting.

My group will still have to pay for 16 seats.. we may not take up the whole 18" per person... the Biggest Losers each also have to have tickets... they may take up more than 18" per person.

the venue can only sell so many "seats"..

since there is no such thing as a .5 person, it's a person.. round up..
 
88twin said:
ok let me throw this into the mix.14 benches at 128" ea.= 99.54 people

99 oc (i never count half peoples)
128"/18"/person = 7 persons

14 * 7 persons = 98 persons.

The intent of the code is to accurately count the seats. 2" on one bench = 0 seats...even if you try it 14 times.
 
Peach, I think NFPA 101 is enforced to some extent in Georgia y by the State Fire Marshal.

In 120-3-3 RULES AND REGULATIONS, Item (69) NFPA 101, 2000 Edition, Life Safety Code Modifications:

The 2000 Edition of the Life Safety Code is adopted with modifications so as to be applicable to proposed (new) and existing buildings and structures. Unless noted otherwise herein, operational provisions such as fire drills, emergency egress and relocation drills, development of fire or emergency plans, and regulation of contents of the various provisions of NFPA 101, Life Safety Code shall not be applicable to proposed (new) or existing buildings, structures, facilities, or conditions. The operational provisions of the International Fire Code (IFC), as adopted by the Chapter 120-3-3 of the Rules and Regulations of the Safety Fire Commissioner shall apply to proposed (new) and existing buildings, structures, facilities, and conditions.

(a) Modification to Chapter 1:

1. Delete 1.2.4 (1) in its entirety and substitute in its place the following:

“(1) General fire prevention or building construction features that are normally a function of fire prevention codes and building codes. The International Fire Code (IFC), as adopted by Chapter 120-3-3 of the Rules and Regulations of the Safety Fire Commissioner, and the International Building Code (IBC), as adopted by the Georgia Department of Community Affairs are applicable, and there use along with other codes and standards shall be coordinated with this Code, as set forth in 1.4.3, and Table 1.4.3, CODES REFERENCE GUIDE.”

2. Add a new subsection 1.4.3 to read as follows:

“1.4.3 Code Coordination. This Code shall apply to all proposed (new) and existing buildings, structures and facilities, except as herein provided, and shall be utilized in conjunction with the IBC, the IFC, the IMC, and the IFGC, to the degree provided in Table 1.4.3, CODES REFERENCE GUIDE.

Exception No. 1: This Code does not apply to one- and two-family dwellings or one- and two family row houses (townhouses) separated by a 2-hour firewall, except as specified in Chapters 26, 30 and 31.

That table, as noted on the Ga Fire Marshal web site in document CHAPTER 120-3-3 RULES AND REGULATIONS FOR THE STATE MINIMUM FIRE SAFETY STANDARDS appears to require compliance to both the LSC 101 and the ICC Codes.

Am I reading it wrong?
 
RLM

As a former Georgia plan reviewer you have to look at the coordination document. (1.4.3, and Table 1.4.3, CODES REFERENCE GUIDE) It lists which code, and code official, has the authority to make the particular call. It is a little confusing sometimes but it used to be a lot less forgiving if the Building Official and the Fire Marshal did not get along as was usually the case in the 'dark ages'.
 
ok... you still have to plan on the MAXIMUM number of people getting out.. not a bunch of fat old farts who occupy more than 18" each...

It's an exiting guidline..

plan for the worst.. (the code worst)... .5 people is a people..

so is .25, or .15.. or .0005

for exiting.. you round up..
 
Peach

I will die for your right to round up, but as for me and my house, I will go with the integer of the division for bench seating.

Years ago when I was hired to renumber the bench seating at LSU Tiger Satdium, we were ordered to renumber with only 16" per seat.

My grandmother (a die hard tiger fan) never forgave me.

Peace

Happy Easter
 
I always use the complete decimal measurements to calculate square footage but I always round the result down in occupant load/exiting calculations. There is no such thing as .5 person.
 
In this particualr case, they wanted the occupant load reduced (hence, the 2" per bench) for the purpose of reducing the occupant load relating to the health department's criteria for the septic system design. Apparently, they were 14 people over the threshold for requiring a pump system over a conventional gravity flow system. In our state, the fixture unit counts are based on a figure of 30 sq ft per person, which greatly reduces the occupant load with regard to fixtures, plumbing, etc. The health department uses the occupant load as determined for egress etc for the design of the system, not the fixture/plumbing occupant load. It seems to me that the septic system would have the same design criteria as the plumbing system, but...that's not my department.

Their occupancy has been reduced by 14 people, and everyone is happy.
 
Back
Top