I am struggling to find information regarding how the percentage of males expected to use restrooms with urinals is calculated. We have a building with core M/F restrooms on every floor and a few gender neutral restrooms (without urinals) as well. What is the correct way to calculate this percentage? Is it fixture based or something else?
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David Posada
Integrated Design & LEED SpecialistSERA Architects
LEEDuser Expert
1980 thumbs up
March 2, 2020 - 5:17 pm
The Indoor Water Use reduction calculator spreadsheet (filename "4v4 1_ Indoor Water Use Reduction Calculator_v04_0.xlsm" available in the Resource downloads) has some guidance in the comments added to the spreadsheet for cell I16, Percent of males expected to use restroom with urinals:
"To determine the percent of males expected to use restrooms with urinals:
Enter 100% if all male and gender-neutral/ ADA restrooms have urinals.
Enter 0% if the project contains no urinals.
If the project includes separate all-gender/ADA restrooms without urinals, enter the default value of 95%, or a project specific estimate based on the project's restroom layout and anticipated usage patterns or weighted fixture counts."
Given this, it's up to our judgement to determine if it's appropriate to use a percentage lower than 95% for a project. My impression is that if you have a project with common (multi-person) restrooms that have fixture counts close to the quantity needed to meet the occupancy demands, and a few gender neutral restrooms without urinals, then 95% makes sense. If there are a greater number of gender-neutral restrooms, and a reduced number of fixtures in the common restrooms, then it's appropriate to use a lower percentage. There's currently no formula or guidance for estimating this. We've seen projects where 80-90% seemed appropriate.
Incidentally, we've seen a shift in some markets where there's a desire to provide more single user/ gender neutral restrooms. We should point out for these projects that using more gender neutral restroom without urinals can limit our water use reduction targets, since low flow urinals (0.125 gpf) have a huge water reduction benefit.
There's another note in the Fixture Information table for calculating percent of Occupants using a particular fixture (toilets, urinals):
"Do not reduce the percent of Occupants for urinals if the project includes separate gender-neutral or ADA restrooms without urinals. The calculator will account for the urinal usage based on the Percent of males expected to use restrooms with urinals entered above."