Question 1: Typically in school projects we have several unisex restrooms without urinals. Historically, in LEED version 3, Our way of dealing with this would be to add all the fixtures in restrooms with urinals and divide it by the total number of fixtures in the urinal restrooms + unisex restrooms. We then use that percentage of fixture distribution to represent the percentage of male populations that have access to urinals to discount for lower urinal use.
Now, the LEED v4 water calculator has two fields to help account for this. There is a box for "Percent of males expected to use restrooms with urinals" (presumably calculated using our historic methodology), and then another box in the fixture table that asks for "Percent of Occupants with access to the fixture. If the fixture is installed in all restrooms, use 100%".
One might think these two boxes should be the same. But, there is no indication that I can find about why there are two boxes instead of just one. And changing the values in one impacts the other. For example, let's suppose we were to say 100% of occupants were expected to use urinals but only 37% of urinal access came from restrooms with urinals in them. That results in a specific calculation. That seems like a different statement - and with different calculator results - than if 37% of bathrooms have urinal access, and only 37% of the male population was expected to use them.
The definitions in the calculator seem to be the same for percent of males expected to use urinals, and percent of occupants expected to use the urinal fixture, but so why then have two different boxes to input this information?
Question 2: In this particular school project we have many classrooms with a dedicated unisex restroom with no urinal. We also have community restrooms with urinal access for all students. Students in the classrooms with unisex restrooms would presumably use both the community bathroom with urinals and their own unisex bathrooms without urinals.
So, it seems like I would need to create two student user groups: One for students with access to the unisex in their rooms and the community bathroom, and one for students with only access to the community restrooms. Presumably, the former group would need their own calculation of urinal access, and the latter group would just follow the calculation of urinal access for other teachers and regular building users (there are no dedicated faculty restrooms to skew the numbers).