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Things have gotten harder
Water-use reduction is a good opportunity for all projects to earn points. If you’re familiar with this credit from earlier versions of LEED, though, keep in mind that it’s gotten harder. LEED 2009 introduced WEp1: Water Use Reduction as a prerequisite, calling for a 20% reduction for all projects. In NCv2.2 WEc3, which used to award a one point for a 20% reduction,. The points for 2009 now start with a 30% reduction with for two points, and go up to four points for a 40% reduction.
The baseline for measuring water savings has also become more demanding. The LEED 2009 baseline for commercial lavatory faucets is 0.5 gallons per minute (gpm), whereas the previous baseline was 2.5 gpm.
It’s still very doable
Even with these more...
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23 Comments
USGBC provides additional guidance
The USGBC just posted a new document providing additional guidance on WEp1 and WEc3. This document covers fixture groups, daily use calcs, dual flush flow rates, and autocontrol faucets. Link here: http://www.usgbc.org/ShowFile.aspx?DocumentID=6493
Hospital water use?
In the credit language, hospital patient rooms are allowed to have faucets with 2.2 gpm. Does this hold true for operating rooms and doc offices? It seems it should, as in those areas you don't want to have water flow restricted....
And how does that fit into the template, if at all? Its very challenging to quantify how often those are used and for how long....
Ben Stanley replied Sustainability Manager, YRG sustainability Jan 29 2010
Tommy,
The operating room water use should be considered process waterProcess water is used for industrial processes and building systems such as cooling towers, boilers, and chillers. It can also refer to water used in operational processes, such as dishwashing, clothes washing, and ice making. and excluded from the calculations.
Faucets in the doctor's office could be considered private, normal, or process depending on the use. If it's used in the course of providing medical treatment then probably process. If it's like a typical commercial bathroom then would follow the 0.5 baseline. Private is usually reserved for residential/hospitality or executive suite type bathrooms but maybe there is a case for private in a doctor's office.
Lauren Glasscock replied Sr. Sustainability Professional, KEMA Services, Inc. Feb 01 2010
It is my understanding that only "kitchen sinks" and "lavatory faucets" should be included under WEc3 in terms of sinks. Lab sinks would be excluded as well as operating room water use as Ben mentioned. I guess I would ask how one should define a "kitchen sink" to determine inclusion in the calculations.
Calculating FTE/Transients for Hospital environments
I was wondering if the USGBC has provided any guidance regarding calculating the FTEFull-time equivalent (FTE) represents a regular building occupant who spends 8 hours a day (40 hours a week) in the project building. Part-time or overtime occupants have FTE values based on their hours per day divided by 8 (or hours per week divided by 40). Transient Occupants can be reported as either daily totals or as part of the FTE. Residential occupancy should be estimated based on the number and size of units. Core and Shell projects should refer to the default occupancy table in the Reference Guide appendix. All occupant assumptions must be consistent across all credits in all categories./Transients/Visitors, etc for a hospital. Should patients be partial FTEs or visitors? Does it depend on the kind of patient that they are (outpatient vs inpatient)? Do any of the hospital FTE, such as inpatients have to be residential FTE? Is there guidance in LEED for Healthcare? Our project is registered under LEEDv2.2.
Mara: perhaps you have a good idea from your hospital experience?
Thank you!
Mara Baum replied Sustainability Coordinator, Anshen + Allen Architects Feb 03 2010
There is limited guidance from the USGBC on this matter. Inpatients are considered to be residents; outpatients are transients.
Calculating transients is often an exercise in estimation, and this is especially true for healthcare, because so many of the staff are mobile -- e.g. doctors on rounds who may pop into a building for just a few minutes or maintenance personnel who work in one building periodically but may have a permanent home in a different building. This type of occupant is usually a transient, although you should use common sense to determine your approach. You should work with your client to estimate these numbers, as well as outpatients and typical visitors per inpatient. They will probably hate this! Start with everything you know about the building, then and ask questions as specific as possible. For example, a desk in an office building often represents 1 FTE... but it could represent 3 in a hospital nurse station... even if the desk is used only two individuals, because shifts are often 12 hours.
I have not found the LEED for Healthcare draft (now quite old) to be useful on this topic, as it's something that is more likely to be addressed in a reference guide.
Lauren Glasscock replied Sr. Sustainability Professional, KEMA Services, Inc. Feb 08 2010
thanks!
Hotels (w/ conference space), FTE, & water usage rates - SSc4.2?
Many CIRs address the issue of FTEFull-time equivalent (FTE) represents a regular building occupant who spends 8 hours a day (40 hours a week) in the project building. Part-time or overtime occupants have FTE values based on their hours per day divided by 8 (or hours per week divided by 40). Transient Occupants can be reported as either daily totals or as part of the FTE. Residential occupancy should be estimated based on the number and size of units. Core and Shell projects should refer to the default occupancy table in the Reference Guide appendix. All occupant assumptions must be consistent across all credits in all categories. to an extent, but it seems there might be multiple strategies for accounting for various occupancies. (Hotels near transit can exclude guest occupants- v2.2 SSc4.2 1/23/09, modifying the FTE to place guests in the transients category - v2.1 SSc4.2 6/20/2008, etc). And many of the referenced CIRs are built up from College Campuses, then Airports, but Hotels still seem a little mysterious.
For FTE it is clear: CIR v2.1 SSc4.2 6/20/2008 and the guest belong in transient calculations.
But would guests count toward a Residential occupancy (same usage rate essentially as a home, i.g. there at morning and night)?
Based on this CIR, guest would only be transient in the correct FTE, right? Whereby certain transient populations can be excluded from the calculations in determining the number of required bike storage spaces and showers.
Ssc4.2 is really about making biking more convenient for full time users, however, in this credit, FTE numbers have an impact on usage and occupancy numbers effect overall end water use (and water reduction).
It seems awkward then to place hotel guests in transient for WEc3.1 as guests are more likely to shower and use water fixtures.
I'm posting this same inquiry in SSc4.2 in regards to FTE numbers for hotel guests.
John Beeson replied Chief Mystic in Resident, betterENVIRONMENT, LLC Feb 11 2010
This should have a preview option. I forget some things.
I'd like to add the question about usage rates as well to this.
The LRG has water use calculations which indicate fixture usage rates based on residential standard calculation methodology presented in the LEED-NC v2.2 Reference Guide, Third Edition on page 142.
So, would guests count toward a Residential occupancy (same usage rate essentially as a home, i.g. there at morning and night)? Unless special conditions exist, projects should assume a 50/50 male/female ratio and an average of 5 fixture uses per day for residential usage.
Any thoughts are appreciated.
Mara Baum replied Sustainability Coordinator, Anshen + Allen Architects Feb 15 2010
I would calculate hotel guests as residents, and yes, they should definitely have an assumed 50/50 male/female usage. This is always true unless there is a very specific and provable reason otherwise, which I can't really foresee for a hotel. You would also have FTEs (hotel employees) and transients (visitors + those who come for events, conferences, etc.) These would all be calculated separately in the WEc3 template. You will have to work with your client and design team to determine how many transients are appropriate based on event spaces and other hotel practices.
John Beeson replied Chief Mystic in Resident, betterENVIRONMENT, LLC Feb 17 2010
Thanks Mara, that's what we suspected after looking thru LRG BD+C (we are analyzing this for NCv2.2). But, still, for SS4.2 should different FTE be applied vs WEc3? As CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide v2.1 SSc4.2 6/20/2008 where the guests belong in transient calculations.
Detention facilities
Another 24/7 facility. I assume every 24 hours will constitute 3 FTEs for a given staff position? Inmates are "residents." Just confirming.
When will USGBC get LEED Health Care out any way????
Tristan Roberts replied Editor – LEEDuser, BuildingGreen, LLC Mar 11 2010
Yep, sounds like you got it right with the three FTEFull-time equivalent (FTE) represents a regular building occupant who spends 8 hours a day (40 hours a week) in the project building. Part-time or overtime occupants have FTE values based on their hours per day divided by 8 (or hours per week divided by 40). Transient Occupants can be reported as either daily totals or as part of the FTE. Residential occupancy should be estimated based on the number and size of units. Core and Shell projects should refer to the default occupancy table in the Reference Guide appendix. All occupant assumptions must be consistent across all credits in all categories.'s. No word on LEED for Healthcare—waiting on the next public comment period.
LEED NC v2.2 - WE c3
I used the submittal template from LEED online, and my project achieves a 43% reduction in water use, which is enough to achieve an ID credit under version 2.2. My question is whether I need to actually fill out a submittal template for ID c1. Is it enought to just complete the submittal template for WE c3?
Peter Doo replied Doo Consulting LLC Apr 04 2010
Save the template from WEc3 as a pdf and upload it as a document for the IDc1 credit. You still have to fill out the IDc1 Template. The Intent is the same as WEc3, the Requirement is to exceed the exemplary credit threshold, and the Approach is the approach that you took to achieve your water efficiencies.
ID Credit for Exemplary Performance in water savings
According to page 168 of the LEED 2009 reference guide, process waterProcess water is used for industrial processes and building systems such as cooling towers, boilers, and chillers. It can also refer to water used in operational processes, such as dishwashing, clothes washing, and ice making. savings does count towards ID Credits (new construction category). It seems then that process water savings count for 1 point when striving for 45% or greater water savings. Process water savings don't add to any points in WE 3 I don't believe. I understand that if plumbing fixtures alone qualify for less than 40% then the project will be getting less than 4 points under WE 3. One additional point seems to be available for designs that save in excess of 45%, plumbing fixtures plus process savings.
Anyone have experience with this?
Thanks!
Dan
Mara Baum replied Sustainability Coordinator, Anshen + Allen Architects Apr 06 2010
You are right in that process waterProcess water is used for industrial processes and building systems such as cooling towers, boilers, and chillers. It can also refer to water used in operational processes, such as dishwashing, clothes washing, and ice making. savings can not apply directly to WEc3, but it can contribute to an ID point. If we maintain credit interpretations from LEED NC, you need to be able to prove that process water savings represent at least 5% of the base building water use as defined by WEc3. I think it's a reasonable assumption to thing that you can get an additional point if you can prove a savings in excess of 45% with both regulated and process water included.
Mixed Use Building
How do you calculate the water use reduction for a mixed use building which contains 7 floors of commercial space and 34 floors of residential space? How do you account for the different usages for each floor type?
Tristan Roberts replied Editor – LEEDuser, BuildingGreen, LLC Apr 28 2010
The documentation for this credit is mostly populated from the LEED Online form for WEp1. When you're documenting WEp1 in the LEED Online form, you have he opportunity at the beginning to define "Fixture Groups," which could correspond to different usage types like those in your project.
LEED V3 / WE C3 Duration of lavatory faucets
How Do you calculate the gpf of commercial lavatory faucets without metering? We have a flow rate per minute of 1.32 gallons (5 liter). Does anyone have experience from other projects what duration e.g. 30sec (similar to one usage) can be used for the calculation? Thanks a lot!
Tristan Roberts replied Editor – LEEDuser, BuildingGreen, LLC Jun 10 2010
I would start by reading this USGBC document, which clarifies a lot of common questions about calculations for this credit. Post back here if you still have questions after reviewing it.
CIRs
When I login to LEEDonline and look under this credit, I don't see any CIRs. Upon clicking the "Credit Interpretation Rulings" link, a window pops up claiming there are none. I find this hard to believe! I'm guessing there aren't any since 2009 came out possibly?
My question that I hoped to answer by looking at CIRs was how to treat hotel guests. The user groups have already been defined, but I'm guessing that the intent of the credit is best met if I take away urinal use for male hotel guests, as it would be unfair to account for their usage when guests don't normally use the public restrooms. Should I edit the Visitor (where our guests are included) urinal fixture use to zero?
Thank you!
Erik
Erik Turner replied Mechanical Engineer, Robison Engineering Aug 12 2010
Well I see now that the CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide link is project specific. And the guidance for the credit has confirmed my thoughts on the urinal use. I don't see a way to delete my comment- if a mod can, please feel free.
Erik
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