Occupant Load round up or down

So i was doing one of your practice tests and for occupancy load i got 114.7 people. Since you can’t have a .7 person max occupant load allowed would be the more stringent value 114 not 115 correct? That is what i was taught in the office world for permitting purposes. Your exam marked it incorrect and the answer was 115. What does NCARB say?
In the same light for plumbing fixtures I was taught to round up to say if 5.4 fixtures are required we round up to 6 fixture to be more stringent. Correct? Or have i been mucking up my test by going with real world calcs vs what NCARB thinks is right? Where can I confirm the “right” way for NCARB? Can you imagine the number of questions i got wrong by 1 fixture or 1 person? i’m horrified! all this work and i’ll never get it right as long as i can’t get confirmation which way is correct!!! this could go on for years!!!

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Hi @najia.hashim ,

This is a tricky area! No worries!

In your first exam you would round up to the nearest full occupant (because you can’t cut occupants in half). This is rounding to the most stringent value (in the eyes of the code) because you have to account for exit widths of one more full person.

You must round up for plumbing fixture counts as you’ve described.

And I think you were correct in both of your assessments, there was just some confusion about what was most stringent as far as occupants where the building code is concerned!

This question gets asked a lot.

Check out some of the previous posts on the community tackling this question below:

Hope this helps!
-Darion

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@coachdarionziegler
i got little more confused after seeing building code illustration p367, it round down the meeting occupant load from 32.14 to 32.

  1. do we use the round to the nearest number rule, or always round up/down rule ?
  2. assume we always round up/down first before we add them together instead of add the decimals then round?
  3. say there is a room , occupant load is 49.6, so use 50(it need 2 exit) or we use 49(one exit)
  4. say there is a room , occupant load is 49.1, so use 50(it need 2 exit) or we use 49(one exit)

Hi @xurubi ,

My understanding is it is always best to round up when dealing with occupants as you can’t have a partial occupant and when it comes to exiting you always need to deal with the ‘worst case scenario’ which means rounding up to the nearest whole occupant.

The reason most jurisdiction require you to round up is this section from IBC 2018.
image

The 2018 IBC Code Commentary goes on to state, “The worst case scenario should be used to determine the requirements for means of egress elements”.

However, this doesn’t mean that there isn’t some ambiguity in this and it’s always enforced exactly in this manner by the individual AHJ. I’ve read that NFPA actually does allow for traditional rounding (rather than forced rounding up).

So, I wouldn’t let this example of traditional rounding you found in Building Code Illustrated get under your skin. (PS - I’m afraid I had to delete the screenshot as we do not allow posting of any paid content, 3rd party or Black Spectacles). I wouldn’t worry too much about it as I think it’s unlikely the ARE is going to throw you a question where the occupant load could be either 49 or 50 based on rounding. Plus, any questions that require rounding will prompt you to round.

If you encountered this in the real world, likely you would simply adjust the areas in some ways so it was less ambiguous whether the occupancy should be rounded up or down so the AHJ would clearly agree that the occupancy was not over 49.

Here’s an article on Hyperfine you might find helpful:

Hope this helps!
-Darion

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@coachdarionziegler thank you so much , this is by far the clearest answer.

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