Single User Restroom Plumbing Fixture Calculations

[lecorybusier]

Per 2902.1.1 (2021 IBC) you don't have to split by gender in order to determine fixture requirements when providing single user, non gendered restrooms.
This simplifies things greatly when looking at occupancies where the fixture ratios are the same between men and women.
However, how do we calculate fixture minimums in this scenario when fixture ratios are different between the sexes?
For example at theaters where the WC ratio is 1:125 for men and 1:65 for women?

 

[Yikes]

I don't have an answer directly from code, but it would seem to me that a 66th person using the restroom would require women to have access to 2 toilets.
Therefore for a single-user non-gendered restroom, according to the code reference you provided, the maximum occupant load is 65 people (men and women combined).

P.S. Welcome to the forum!

 

[Jay Smith]

You calculate the fixture count based on the table, but without the restriction of assuming half the occupant load is female and half is male. If you know the occupant load is expected to be 90% male, you could in theory calculate the fixture requirement for the women based on only 10% of the occupant load.

 

[mtlogcabin]

Same as before. 100% occupant load and apply 50% male and 50% female

 

[bill1952]

Since the op referred to theatres, I'll mention that the code required minimums are wholly inadequate in my experience, requiring approx 1 fixture per 25 seats. And keep in mind a matinee may well be 90% female. Just wanting to emphasize the inadequacy of the codes as "good design" for something's.