My question is 2-fold:
We're trying to complete the WEp1 form using a single fixture group (office) for a pre-1993 commercial office hi-rise. The hi-rise has 37 floors with the same usage patterns and hours on each floor respectively, and any "as-needed" partial fixture upgrades and replacements weren't installed uniformly by floor or gender so I'm unclear on how to accurately input the fixture data so that the daily use calculation appropriately represents the fixture usage. The flush fixture inventory is as follows: (95) 35 Men's & 60 Women's 3.5 gpf WC modified to 2.4 gpf; (30) Women's 1.6 gpf WC modified to dual flush 1.1/1.6; (16) Men's 1.6 gpf WC; (52) Men's Urinals 25-1.0 gpf & 27-1.5 gpf modified to 0.5 gpf respectively.
1) When upgraded fixtures have been installed sporadically throughout 37 floors and in the case of the dual flush toilet, only within some of the women's rooms and none within the men's rooms, does it matter that the template doesn't account for the gender inequality within the automatic daily use calculation nor the proportional use of the number of fixtures by type of fixture?
We also have reduced occupancy to account for so we need to attribute a default head count to our vacant space - however the vacant space within the facility isn't centralized and doesn't have an associated FTE number included within the PIf3 documentation.
2) If we add another Fixture Group (vacant) to represent the unoccupied space - how would we calculate the number of fixtures to attribute to the 2nd fixture group since the vacant office space shares the same set of fixtures as the occupied office space?
I've tried to input this scenario into the forms according to instructions within the LEED Reference Guide for EBOM 2009, the Water Use Reduction Additional Guidance, and the Reduced Occupancy Guidance for LEED 2009 EBOM, but I feel like those instructions don't definitively explain how to document and calculate this type of scenario to accurately represent the WE data.
Thanks for your help.
Dan Ackerstein
PrincipalAckerstein Sustainability, LLC
LEEDuser Expert
819 thumbs up
February 15, 2011 - 4:52 pm
Complicated question Joanne - I'm struggling a bit to even understand the issues at hand. I think the key is that you should not feel limited by the template - what matters is accurately representing fixture water use in your building. That may mean creating separate Fixture Groups for the male and female populations of a given area. As to the question about the vacant space - no need to account for it separately if that space is served by a shared fixture location. What matters is how many people use a given fixture, how often, and how much water that fixture uses. Vacant space is only addressed separately if it contains dedicated fixtures.
I'm not sure if I helped at all or made things worse!
Dan
Jason Franken
Sustainability ProfessionalLEEDuser Expert
608 thumbs up
February 21, 2011 - 10:57 am
Joanne, it sounds like you've already done a fairly thorough job of conducting a water fixture inventory of the building. One option would be to have a single fixture usage group for the entire building and include weighted average flow and flush rates for each fixture type. This is allowable because all occupants in the building have access to all fixtures in the building. Think of it like a pool of fixtures and any occupant can use any fixture they wish at any given time.
If you'd like to try it this way, you would need to provide a detailed narrative (in addition to the WEp1 Credit Form) that summarizes the building fixtures and their installed flow/flush rates. Then you would need to map out the calculations you would use to come up with a weighted average flow or flush rate for each fixture type. Include a separate summary table that lists the weighted average flow/flush rate for each fixture type and make sure that this table matches the data you enter in the Flow Fixture Data and Flush Fixture Data tables on the Credit Form. Finally, make sure you include a manufacturer cut sheet for each fixture that has an installed rate that is higher or lower than UPC/IPC standards. This documentation will help support the data points that you use in your calculations to determine the weighted average flow and flush rates.
Throughout all of this, I'd recommend you maintain a 50/50 gender ratio for your fixture usage group and make sure that you account for potential occupancy of your vacant tenant space according to the Reduced Occupancy Guidelines.