My question is pertaining to the water calculator sheet for WEp1 pre-requisite. This is for a LEED v3 New Building office project.
We recently received comments regarding lavatory faucet and showerhead fixtures and would like to clarify the following:
1) Only specific people in the building have access to the restroom with a private showerhead fixture and lavatory fixture. If for example we have 100 regular occupants and 250 visitors and only 1 regular occupant will have access to this restroom, the 'Percent of Occupant' will be about 0.25% ( 1/ (250+100) X 100 = 0.25%). Is this the correct method to determine the percent occupant? The spreadsheet rounds the 0.25% to 0% which therefore calculates the water usage 0 as well. In this scenario, should the fixture be completely taken out from the calculation sheet or should the % be rounded to 1%? This issue is with the private lavatory fixture as well.
2) The private fixture type based on the project's plumbing schedule is 'Residential Showerhead' and 'Lavatory - Residential'. It is a private restroom. What is the correct type of fixture option to choose under Fixture Type in the 'Water Use Reduction Calculator'?
Method a)
Choose the 'Public Lavatory (restroom) faucet' and 'Showerhead' options for the two private fixtures and use the default Uses per Day and Total Daily Uses to calculate the Daily Water Use
Method b)
Choose the 'Private lavatory (restroom) faucet - metered' and 'Residential Showerhead' options for the two private fixtures and input 'Other' Uses per Day and 'Non-default' Total Daily Uses to calculate the Daily Water Use
Thank you.
Emily Purcell
Sustainable Design LeadCannonDesign
LEEDuser Expert
370 thumbs up
March 31, 2021 - 10:37 am
1) I would round up to one just to keep it simple and make something show up in the calculator.
2) This depends on the function of the room. Since it's an office project, I assume this is an executive washroom, where only one person has access but they will use it the same way as any other restroom in the building (3 daily uses during the workday)? In that case it would be Method A.
The "private/residential" uses are meant for something like a hotel room where someone will be spending a full day/night in the space. So if the private washroom is for someone who is staying overnight on site, then those categories would apply.
David Posada
Integrated Design & LEED SpecialistSERA Architects
LEEDuser Expert
1980 thumbs up
April 6, 2021 - 4:55 pm
I agree with Emily and would only add that you could also create a second Fixture Group for that one person.
On the 'Instructions' tab of the water calculator spreadsheet click Add Group and name it something like 'Private' to create a empty, duplicate worksheet tab. On that sheet, you can set the FTE to 1 and enter the fixture flow- and flush-rates for that one restroom.
Fixture Groups are good for when some users have access to different fixtures, or have different daily use patterns.