When conducting means of egress calculations, is there a standard way to round? For instance, if the square footage of a room suggests 48.1 people, is the occupant load always rounded (conservatively) to 49 people? Or does rounding follow standard convention, where 0.50 and up rounds up, and everything below rounds down?
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8/22/2017 12:19:03 pm
I'm glad to see I'm not the only one who has questions on this. All of the problems I've seen always round up (e.g. 48.1=49). While this approach makes sense to me for egress components (e.g. a stair required to be 63.2 inches wide should be 64), I always tend to think rounding down for occupancy is more conservative. For example, if an occupancy is determined to be 48.1, rounding up to 49 would actually put you above the load factor for that space. By rounding down, I think you ensure you are not over crowding the space (even 48.9 would go down to 48). However, like I said, everything else I see rounds up.
8/22/2017 09:20:32 pm
Someone correct me if I am incorrect, but you always need to round up on occupant load calculations. Even if the solution to the problem gives you 48.1 occupants, you need to account for that .1 of a person. Since you can't have .1 of a person, you need to round up to a whole number/person. Otherwise, rounding down on occupant loads throughout a building could potentially skew the total occupant load by multiple occupants. This then causes inaccurate and incorrect numbers for the requirements for building exit features (e.g. stair widths, door widths, occupancies, etc.)
8/28/2018 11:11:33 am
It depends if you are using NFPA or IBC.
8/26/2021 05:14:17 pm
Actually, if you are not using some arbitrary legal proscribed construct, and are allowed to put some science into the decision, here is a suggestion.
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