NC 2009 WEp1: Water Use Reduction—20% Reduction

Nadav Malin replied President, BuildingGreen, LLC Aug 11 2009

Great info here. I'm curious whether your dual-flushA type of water-saving toilet that gives a choice of flushes depending on the type of waste — solid or liquid. WC is based on a residential 1.6/0.8 gpf or commercial 1.6/1.1 gpf rates.

Dave Intner replied Firmitas Architecture & Planning Sep 16 2009

I believe that you can get better savings with lavatory faucets if they are metering faucets (manual-on, auto-off as most new public lavs are nowadays); the standard given there is 0.25 gallons per cycle. Toto faucets, as an example, use 0.09 gallons in a 10-second cycle.

Tristan Roberts replied Editor – LEEDuser, BuildingGreen, LLC Sep 16 2009

Do you have any data or calculations on this, Dave, or anyone? Published studies have tended to show that fixtures with sensors use more water on average than those without.

Brenden McEneaney replied Sep 17 2009

It is certainly more challenging, but it also can strongly depend on your occupant types. In a hotel project, you'll find that showers dominate water use (at least, the water use that's considered in LEED...). If you've got a lot of students/visitors, waterless urinals have a more significant contribution.

1.5 or 1.6 gpm showerheads are out there and are good.

For a typical office building, you might also go to the 1.0 gpf pressure-assist toilets. That makes 3.0 gal/day for female users vs. 3.2 with regular dual flush or 3.8 for commercial dual-flushA type of water-saving toilet that gives a choice of flushes depending on the type of waste — solid or liquid.. But it's still not 40% at the fixture level so you need to make up for it with the urinals.

I wonder where the occupant usage rate data originally came from. It seems like this might be an area for future research by USGBC to test and verify these assumptions, since they are the foundation for the indoor water usage estimates.

Dave Intner replied Firmitas Architecture & Planning Sep 24 2009

Tristan- I don't have any calculations, but the Toto product data sheet is available here: http://admin.totousa.com/Product%20Downloads/SS-00420,%20TEL3%285%29GS,%... . As I found out after a recent punch-list walk, the .09 gp/cy model is no longer available; its replacement model is a 0.17 g/cy. I should note that I have no particular affinity for Toto; it's just the only one I've found so far (in my admittedly limited research) that quantifies both flow rate and gallons per cycle on its data sheet. I'm sure there are many others.

I'd be curious to see the studies you reference about fixtures with sensors using more water (can you post some links?); if true, then it would appear the USGBC has it backwards by encouraging a preference for metering faucets in the new credit requirements.

Jean Marais replied b.i.g. Bechtold INGENIEURGESELLSCHAFT MBH Sep 29 2009

I also made some rudimentary calcs and get to 20,8% possible savings using some German industry water saving features. This let's me believe that other than having a grey water system or using non-convensional means, getting to 30% is not possible. Almost like it should fall into Exemplary PerformanceIn LEED, certain credits have established thresholds beyond basic credit achievement. Meeting these thresholds can earn additional points through Innovation in Design (ID) or Innovation in Operations (IO) points. As a general rule of thumb, ID credits for exemplary performance are awarded for doubling the credit requirements and/or achieving the next incremental percentage threshold. However, this rule varies on a case by case basis, so check the credit requirements., i.e. more than high performance.

Seema Pandya replied Sustainability Manager, YRG sustainability Aug 13 2009

I would start by defining your user groups and what fixtures they will be using.
For example, if you have 100 patient rooms and all of them have the same type of sink and a private restroom fixtures, you could define the patients as one user group. You would then run the use calculations for each fixture in that user group at the conventional EPAct rates.

* 50 men using the toilet 3 times a day x 1.6g/f (this would change to 2 urinal uses and 1 toilet uses if your design case had a urinal)

* 50 women using the toilet 3 times a day x 1.6g/f

* 100 people washing their hand in the sink every time they used the restroom 3 times a day x 0.5 g/l

Another user group would might be the nurse station, etc. You would run the base case water uses for each user group.

Mara Baum replied Sustainability Coordinator, Anshen + Allen Architects Oct 15 2009

Although I haven't seen the v3 credit template for this (are samples available for download?), if it is similar to v2.2, then patients are considered residents; staff (nurses, doctors, etc.) are considered FTEs and family are considered transient visitors. This gives the standard fixture use rates. Challenge 1 is that FTEs can be very hard to pin down for a single building that is a part of a larger hospital campus, and that family numbers are just estimates. Challenge 2 is that staff wash their hands many, many times more than the basic LEED rates; there are estimates of up to 12x per hour -- yes, hour -- though I think that is high for most circumstances. Challenge 3 is that some regions have flow rates dictated by code that are different than the EPAct rates. Challenge 4 is that any product with aeration is prohibited for infection control purposes; only laminar flow products are permissible, and there are fewer of them available. Challenge 5 is that very low flow faucets (like the ones required) can potentially take a long time to get to hot, depending on how the hot water loop is set up -- this is a big problem for surgeons and others. (These are just a few of the challenges... are you excited yet?) A lot of hospital projects have shied away from this v2.2 credit given the challenges, but that won't be an option any more. Good luck.

Mara Baum replied Sustainability Coordinator, Anshen + Allen Architects Oct 15 2009

p.s. I gave a webinar for H2E on plumbing fixture selection for healthcare in 2008 -- you can download the slides from http://www.h2e-online.org/teleconferences/ConferenceDetails.cfm?Date=200... (scroll down)

Briana Sprague replied LEED Review Team Leader, NSF International Feb 15 2010

I still have issues about Mara's 2nd challenge from above: "Challenge 2 is that staff wash their hands many, many times more than the basic LEED rates; there are estimates of up to 12x per hour -- yes, hour -- though I think that is high for most circumstances."

In NCv2.2 CIR dated 2/1/0/09, exam room sinks were designated as process usage. This issue is not addressed in the LEED-BD&C 2009 Ref. Guide (maybe I am missing it) and the CIR not longer applies.

What do we do with the exam sink usage for the 2009 rating systems?

Thanks!
Briana

Mara Baum replied Sustainability Coordinator, Anshen + Allen Architects Feb 15 2010

Briana, I'm not sure which you have an issue with: that staff wash their hands so many times, or how to deal with the sinks that they use in LEED. The first issue is definitely debatable, and depends a lot on individual facility culture. In theory, staff are required to wash hands between patients, and they often see up to 12 patients per hour. However, some facilities push gels in liu of washes (lots of opinionated backstory here...), and at others the patient count may be lower.

As for how to qualify the sinks used for handwashing, I think it depends on the circumstances. In theory, any sink in a hospital outside of public or staff restrooms could be considered clinical. However, in many buildings the bulk of those sinks are only or mostly used for handwashing, over and over again. In v 2.2, I had heard of projects that included sinks only or primarily meant for handwashing in the LEED calcs -- for example, sinks between corridors and patient rooms. Exam room sinks, which are often used for many things, would (as the CIR states) be considered process. All of these areas are somewhat gray, and I can definitely agree with arguments on both sides, depending on the situation.

As for LEED 2009, I don't think any of us can do much other than guess, though I definitely encourage anyone who hears more to share their interpretations with the LEED User community.

Nadav Malin replied President, BuildingGreen, LLC Sep 29 2009

If you're using LEED-NC then you're right, there is no credit for reducing cooling water use (although there is precedent for getting innovations points for it in previous versions of LEED-NC). I believe that NC doesn't address this simply because in the early days of LEED we were unable to establish a fair baseline from which to compare a project's design and award points.

But you say that this is an existing museum--does that mean it's apply for EBOMEBOM is an acronym for Existing Buildings: Operations & Maintenance, one of the LEED 2009 rating sytems. certification? In that case, there is WE Credit 4: Cooling Tower Water Management, which includes a point for minimizing water use and another for using a nonpotable waterNonpotable water: does not meet EPA's drinking water quality standards and is not approved for human consumption by the state or local authorities having jurisdiction. Water that is unsafe or unpalatable to drink because it contains pollutants, contaminants, minerals, or infective agents. supply.

Joel McKellar replied Research, LS3P ASSOCIATES LTD. Feb 15 2010

You can likely submit credit from the EB systems for an ID point in LEED-NC or CS and it's not covered elsewhere.

Dave Intner replied Firmitas Architecture & Planning Dec 09 2009

Thanks for posting this link, Shannon; I had been somewhat vexed as to how USGBC intended for us address metering faucets, and this helps clear it up quite a bit.

Yusuf Turab replied Managing Director, Y T Enterprises Jun 02 2010

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. calculations are important in case a project uses graywater1. Defined by the Uniform Plumbing Code (UPC) in its Appendix G, titled "Gray water Systems for Single-Family Dwellings," as "untreated household wastewater which has not come into contact with toilet waste. Grey water includes used water from bathtubs, showers, bathroom wash basins, and water from clothes-washer and laundry tubs. It shall not include wastewater from kitchen sinks or dishwashers." 2. The International Plumbing Code (IPC) defines graywater in its Appendix C, titled "Graywater Recycling Systems," as "wastewater discharged from lavatories, bathtubs, showers, clothes washers, and laundry sinks." Some states and local authorities allow kitchen sink wastewater to be included in graywater. Other differences with the UPC and IPC definitions can probably be found in state and local codes. Project teams should comply with the graywater definitions as established by the authority having jurisdiction in their areas. recycling or rainwater harvesting measures. As per your method above how are you going to calculate the % savings achieved in the design case without having an estimate of the total water consumption and the % of that total water consumption catered via recycling/harvesting measures?

Carmen Cejudo replied Engineering Assistant, LEED AP, Ecotope, Inc. Aug 03 2010

Has anyone had difficulty meeting the WEc3 40% reduction figure by using rainwater? I'm concerened that our project, which shows 51% potable waterPotable water meets or exceeds EPA's drinking water quality standards and is approved for human consumption by the state or local authorities having jurisdiction; it may be supplied from wells or municipal water systems. use reduction with rainwater (21% with just fixtures) may get rejected for the WEc3 points since this issue is unclear.

Tristan Roberts replied Editor – LEEDuser, BuildingGreen, LLC Aug 04 2010

Carmen, the instructions from USGBC are to document this as an alternative compliance path. Other than that, I'm not aware of any major issues that would prevent you from earning the credit. What were your specific concerns?

Carmen Cejudo replied Engineering Assistant, LEED AP, Ecotope, Inc. Aug 04 2010

My concern is that the reviewer would question the wastewater savings from the rainwater system since, as Jean Marais points out, the current Reference Guide states the intent of the credit is "To increase water efficiency within buildings to reduce the burden on municipal water supply and wastewater systems." To me that reads as reducing total water use (including rainwater).

Reducing potable waterPotable water meets or exceeds EPA's drinking water quality standards and is approved for human consumption by the state or local authorities having jurisdiction; it may be supplied from wells or municipal water systems. use is clear, but there is no net impact reduction on the wastewater system, at least not 40% that can be documented. If no other project has been flagged on the wastewater side, then we'll proceed with the alternative compliance path.

Tristan Roberts replied Editor – LEEDuser, BuildingGreen, LLC Aug 04 2010

Carmen, we've had some recent discussion with USGBC on this due to the July addenda, and it's been clear that non-potable waterPotable water meets or exceeds EPA's drinking water quality standards and is approved for human consumption by the state or local authorities having jurisdiction; it may be supplied from wells or municipal water systems. use can contribute to this credit—it's just not the focus of the credit. They'll try to get you to reduce your sewage conveyance under WEc2.

Mara Baum replied Sustainability Coordinator, Anshen + Allen Architects Feb 15 2010

Most of the people who spend time in student housing are people who actually live there, so the transient number is likely to be relatively low. I would speak to the college or university housing office to try to pin down an estimated number. Be up front about this issue, the discussion with the housing office and all assumptions or other ways of thinking in the credit template narrative. In many circumstances guessing transient numbers is an exercise in estimation -- just be honest about it.

Bill Swanson replied PE, LEED AP, BETA Design Feb 26 2010

Yes, at 60 psi. I remember reading a 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 asking about gpm at different psi for some multistory dorm building. The response was that you had to use the gpm value at a standard psi for all fixtures which I think was 60 psi.

Bill Swanson replied PE, LEED AP, BETA Design Feb 26 2010

here's the wording of the actual 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 ruling.

8/27/2004 - Ruling
[Note: this ruling was revised on 9/1/04.]

The underlying assumptions used for calculating projected water use savings should remain consistent between the baseline and design case. Supply water pressure varies across the United States and within individual buildings (as you note in your inquiry). Flow rates at 80 psi are used for the calculations in this credit for consistency and to reward use of efficient fixtures. It is recommended that all projects use the flow rates reported by the manufacturer at 80 psi for comparison with the Energy Policy Act of 1992 flow rates. If you wish to use on-site tests to report the most accurate volume of water use, you must be consistent throughout all fixtures and test both baseline and design fixtures. It is not acceptable to use flow rates at 80 psi for some fixtures and actual flow rates for other fixtures. Measurement can also be used to account for the benefits of whole-building strategies, e.g., flow restrictors at the water service entrance.

Jean Marais replied b.i.g. Bechtold INGENIEURGESELLSCHAFT MBH Mar 02 2010

I didn't check your math, but recently also spec'ed a metering faucet for 0.125 GPC which I rounded to 0.13. It could be that the baseline GPC of 0.25 is based on a much more realistic cycle time of 15 seconds or 12 seconds with autocontrol. 5 seconds is about 33% of 15 seconds.

Andrea Traber replied Director, Sustainable Buildings and Operations, KEMA Mar 05 2010

I wish I did have insight as to why the baseline methodology was changed to GPC, and I concur that you have in fact discovered a significant gap for this fixture type, we have too. One suggestion is to leverage your contact with your assigned review team, provided that your project is registered, and ask them to clarify the methodology, and ask if they are aware of the intent of the GPC calcs. Additional contact with USGBC LEED staff may be helpful. Yet another reason 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 process needs to come back!

Andrea Traber replied Director, Sustainable Buildings and Operations, KEMA Mar 09 2010

I inquired with GBCI and this issue has been identified as needing investigation. It will be presented to the WE TAGLEED Technical Advisory Group (TAG): Subcommittees that consist of industry experts who assist in developing credit interpretations and technical improvements to the LEED system., though I'm not sure of timing. The thinking is that there is a discrepancy in the baseline calculation methodology. Stay tuned and I will post if a clarification is announced.

Hannah Pham replied Mar 09 2010

Dave makes a great point and there is definately a discrepancy here! The .25 GPC baseline for metered faucets, when converted to GPM, equals 1.5 GPM (three times the baseline for public lavs). Perhaps the assumption is that, if the faucet doesn't shut off automatically, people will leave it running three times as long, therefore using three times as much water. I seriously doubt the accuracy of this type of assumption. As Tristan commented above, "Published studies have tended to show that fixtures with sensors use more water on average than those without." At least, if there is no conclusive evidence to the contrary, the baseline GPM should be the same for metered and non-metered faucets. This would also avoid a lot of confusion.

Tristan Roberts replied Editor – LEEDuser, BuildingGreen, LLC Mar 12 2010

We heard from TAGLEED Technical Advisory Group (TAG): Subcommittees that consist of industry experts who assist in developing credit interpretations and technical improvements to the LEED system. support staff on this question. They have been hearing the same question from several sources but don't have a ready answer. They also noted that based on the TAG's current schedule and workload, we may be in for a waiting game.

Dave Intner replied Firmitas Architecture & Planning Mar 12 2010

Shoot, that's a bummer they have it on the back burner. Depending on how they rule on this, it could be a six point swing for our project; possibly more. I wonder if submitting a formal 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 would expedite it.

There is precedent within LEED for multiple analysis paths leading to different outcomes; for example, EAc1.1 (Lighting Power Density) in LEED CI 2009 allows you to use either a Space-by-Space Method or an overall Building Area Method. Same fixtures, same floor area, but potentially different results due to varying baselines.

Just sayin'.

Neil Rosen replied Project Director, North Shore LIJ Health System Mar 17 2010

As an example, Zurn makes it, its not on their standard sheet but just spec it with plain end, flow control in base of spout and that you want 0.5 gpm.

Dave Intner replied Firmitas Architecture & Planning Mar 17 2010

That would be helpful to us, too, if you could point us to a couple, Neil. We have had similar trouble finding them at that flow rate.

Eric Shamp replied Principal, Ecotype Consulting Apr 13 2010

Bradley 1200 series, I'm sure there must be others.

Also, re: the discrepancy issue, my observations of my own habits show that I linger under warm water... and sensor-activated faucets don't discourage lingering, unles they're also metered. Metering does discourage lingering... I get sick of pushing the button over and over and so I go away. In other words, I don't think it's that easy to equate metered usage patterns to non-metered usage. We need field testing, not models.

Tristan Roberts replied Editor – LEEDuser, BuildingGreen, LLC Apr 15 2010

Lou, you can modify your baseline in this case to show that one shower per 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. per day is standard. You'll want to use an efficient showerhead to reduce consumption compared with that baseline.

Does the Russian standard require a certain number of gallons/liters be allocated per occupant per day? That seems difficult to deal with for LEED. Would it be possible to allocate instead a certain number of toilet flushes, showers, sink uses, etc., and substitute effiicient fixtures for baseline inefficient ones?

Hannah Pham replied Apr 16 2010

If you don't have the following document, "LEED 2009 Water Use Reduction Additional Guidance," you might find it useful:
http://www.usgbc.org/ShowFile.aspx?DocumentID=6493
Note 1 on the first page states, "If urinals are not installed for the fixture usage group, then the Water Closet (Male) usage rates are the same as the Water Closet (Female)."

As far as the babies go, birth to two years does sound conservative but since it doesn't effect your % savings anyway, I would probably just keep it simple.

Have fun ; )

Jean Marais replied b.i.g. Bechtold INGENIEURGESELLSCHAFT MBH May 04 2010

Right...for my only WC-no urinal situation, I'm going to trick the LEEDonline form by making 100% Female users (although that's not true) to force the calculation to use "Female" uses per day...which actually only effects the flush fixtures.

There's a leedonline post up here somewhere, where this could also be a useful trick.

Hannah Pham replied Apr 19 2010

Option 2 is more acurate because it accounts for the different male/female ratios. However, remember to use total number of flushes (not people). Your equation should look like this:
[(112.75x1.6)+(92.25x1.6)+(184.5x0.8)]/389.5=1.22gallons
I created an Excel spreadsheet to calculate water savings. If you would like a copy of it, my email address is hpham@uskh.com.

Jean Marais replied b.i.g. Bechtold INGENIEURGESELLSCHAFT MBH Apr 20 2010

Always double check the LEEDonline calculations with your own. They have been buggy in the past.

Tristan Roberts replied Editor – LEEDuser, BuildingGreen, LLC Apr 29 2010

I could see USGBC going either way on this. As Bill Swanson said to me in an email, it could be similar to lighting where we are forced to count the watts of the maximum rating of the socket.

On the other hand, since it defaults to 1.5 gpm you could justify using that, or using some scheduled combination in which you "guesstimate" how it will be used.

Let us know what approach you take and how it pans out—and I hope the credit isn't hinging on this.

Brittany McCollum replied Intern, Viridian Apr 29 2010

Thanks, Tristan.

I was preemptive in asking this question as the owner is currently testing shower heads from a few vendors. We have tested this one (owner installed it at home) and highly recommended it to the owner. However, they have not chosen one yet.

If the owner uses this one, I will let you know how it goes! If we did submit it, I think we would do so at the 1.5gpm rate. Our reasoning is this: The owner has flipped the switch to the 2.0gpm and could not tell a difference. Plus, his wife didn't even know that was an option!

Neil Rosen replied Project Director, North Shore LIJ Health System May 05 2010

If you go with that showerhead, you should be putting 2gpm in the form. You have to go with the worst case.

Tristan Roberts replied Editor – LEEDuser, BuildingGreen, LLC Apr 28 2010

As the WEp1 credit language stipulates, you need to include kitchen sinks and pre-rinse spray valves, but not other common items like dishwashers.

When documenting the credit in LEED Online, you would set up a fixture group for the kitchen that shows  appropriate 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./usage numbers.

Patrick Moore replied GBD Architects, Inc Aug 05 2010

Tatjana's question is a good one. In a restaurant scenario, it stands to reason that the number of kitchen sink uses per 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. and duration would be much higher than say in an office breakroom. However, I haven't found any published guidance from USGBC that would differentiate the two.

Bill Swanson replied PE, LEED AP, BETA Design Apr 29 2010

I don't see why you couldn't. The wording says to use an "aggregate" of 20% less water. I don't see anything saying that one fixture can't use more water.

I think it will be challenging getting 20% water savings with a lavatory faucet using more than 0.5 gpm. I think it's your option to try.

Ben Koenig replied Gensler Apr 30 2010

It's also the IPCInternational Plumbing Code (International Plumbing Code), the EPA and the American Society of Mechanics standards and many local jurisdictions have adopted these codes and standards as their own code. Check your local code. You might be required to use a 0.5gpm faucet anyway.

Other than that I agree with Bill above that one fixture could use more than the baseline as the aggregate of all fixtures required to be included is the key for the LEED calcualtion, but I think it would also trigger a red flag with a reviewer. In any case you are measured against that baseline, meaning if you use more it only hurts you and the other fixtures have to make up for it.

Dave Intner replied Firmitas Architecture & Planning Apr 28 2010

This should be on your plumbing plans, generally on the first sheet or two. It's a table showing the manufacturer, model, flow rates, and other information for all plumbing fixtures installed in your project.

Jean Marais replied b.i.g. Bechtold INGENIEURGESELLSCHAFT MBH Apr 28 2010

Make sure every possible cell in every table is filled...even with a null if nessesary.

Tristan Roberts replied Editor – LEEDuser, BuildingGreen, LLC Apr 28 2010

Jean's advice is good, also make sure all data is entered for fixture groups, fixture data, etc. There's a lot of stuff on this form, so it's hard to give more specific advice without seeing what you're seeing.

Jean Marais replied b.i.g. Bechtold INGENIEURGESELLSCHAFT MBH Apr 29 2010

yes, unfortunately this template is still a bit buggy. this, i think, is partly due to un update being held back until certain hot topic discussion points (usgbc) like rainwater usage can be ironed out. i would advise submitting your own calculations to help the poor reviewers do their job.

Hannah Pham replied May 04 2010

In the template for WE p1, you can change the number of Total Daily Uses to reflect both men and women using the water closet 3 times a day.
The "Y" won't show up until you have uploaded documentation. If you don't have documentation, then you have to check one of the boxes at the end and explain.

Erik Turner replied Mechanical Engineer, Robison Engineering Aug 20 2010

I'm also having difficulty with the 'N' not turning to a 'Y'. I show a 31% reduction at the moment, but no luck. I have uploaded our fixture schedule. One thought is I did change the daily uses of the shower from zero (why is the default zero?) to the proper number suggested in the Reference Guide (1 per person). Adjusting the checkboxes at the bottom did not help. Anyone submit with a 'N' and still get credit for the pre-req?

Ben Koenig replied Gensler May 04 2010

http://www.usgbc.org/ShowFile.aspx?DocumentID=6493
If you follow the link, you'll find a conversion done for faucets, which doesn't seem to make sense, but that's how the USGBC is treating metered faucets vs non-metered faucets at the moment.
However I think you make a good case as well that the baseline is using x-amount of gallons, while your design case is using much less. Also the fact that people use three cycles seems to make sense rather than one cycle

Hannah Pham replied May 04 2010

Gustavo,
To be on the safe side, since there is no baseline for metered showers, I would recommend converting gpc to gpm and assume a duration of 5 minutes. However, 1.2 gpc on a 30 second cycle is equivalent to 2.4gpm, whereas 1.2 gpc on a 40 second cycle is equivalent to 1.8gpm (big difference). You'll need to know the actual flow rate. You might be better off to use a non-metered low-flow showerhead. These are a couple options I have come across recently:

http://www.thenaturalabode.com/mm5/merchant.mvc?Screen=PROD&Product_Code...

http://store.wesgogreen.com/omni-shower-head.html

Showerheads are a great way to get water savings. As one of my co-workers pointed out, the owner can always change them out later if he hates the low-flow. By that time, you have no control of (or responsibility for) water usage. Some low-flow shower heads actually feel the same or better than regular ones, though. They have come a long way.

FYI: I am not an authority on LEED so don't take my answer as the final say. I am just making suggestions.

Have fun! ; )

Jean Marais replied b.i.g. Bechtold INGENIEURGESELLSCHAFT MBH May 05 2010

p171 BD&C userguide Table 2. Default Fixture Uses, by Occupancy Type has Showers as follows

Private Shower @ 2.5 (gpm) at 80 (psi) per shower stall — residential, duration 480 sec

which gives 20 gpc

and

Public Shower @ 2.5 (gpm) at 80 (psi) per shower stall — duration 300 sec

which gives 12.5 gpc

These durations are used to calculate the water volumes used in any event, and although not explicitly a baseline for metering showers, would not be far from the mark. Write usgbc and ask if you could use this as the baseline for metered showers.

Jean Marais replied b.i.g. Bechtold INGENIEURGESELLSCHAFT MBH May 05 2010

per cycle in context of this credit means per event or usage, meaning that the 3 cycles you used in your example per shower equate to one LEED "usage" cycle.

Karen Blust replied Green Building Consultant, CTG Energetics, Inc. May 14 2010

Here is an NCv2.1 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 Ruling that you might find helpful: http://www.usgbc.org/LEED/Credit/CIRDetails.aspx?CIID=829

Josephine de Montmarin replied Communication and Development Officer, MANEXI May 17 2010

Thank you but I don't actually have access to the ruling on the USGBC site. The project is not registered yet as we are trying to determine if it even worth pursuing certification. After all, if we can't meet this prerequisite we're stuck...

Tristan Roberts replied Editor – LEEDuser, BuildingGreen, LLC May 17 2010

Below is the key paragraph from the "ruling" part of 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. Note that this CIR is from an older LEED rating system, and was given in 2004, but it should be able to give you some general guidance on how GBCI is likely to view this issue.

"The underlying assumptions used for calculating projected water use savings should remain consistent between the baseline and design case. Supply water pressure varies across the United States and within individual buildings (as you note in your inquiry). Flow rates at 80 psi are used for the calculations in this credit for consistency and to reward use of efficient fixtures. It is recommended that all projects use the flow rates reported by the manufacturer at 80 psi for comparison with the Energy Policy Act of 1992 flow rates. If you wish to use on-site tests to report the most accurate volume of water use, you must be consistent throughout all fixtures and test both baseline and design fixtures. It is not acceptable to use flow rates at 80 psi for some fixtures and actual flow rates for other fixtures. Measurement can also be used to account for the benefits of whole-building strategies, e.g., flow restrictors at the water service entrance."

Josephine de Montmarin replied Communication and Development Officer, MANEXI May 17 2010

Thank you, that is indeed helpful (although unfortunate in our case). Testing the fixtures directly at the building's specific pressure might work, but how would one go about "testing the baseline fixtures"? Any ideas?

Thank you again for your help, this is much appreciated!

Tristan Roberts replied Editor – LEEDuser, BuildingGreen, LLC May 14 2010

That is correct—they are not. Only shower fixtures count, relative to bathing.

Karen Blust replied Green Building Consultant, CTG Energetics, Inc. May 20 2010

Yes, it is reasonable to assume that hotel room kitchen sinks will be used once a day, with a 15 second duration. Janitor/maintenance sinks are not covered by EPAct and thus do not need to be included in your calculations.

Rick Gehrke replied Consultant, A.C.E. AmBiental May 27 2010

I'd say the science lab and classroom sinks could be counted as 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..

Karen Blust replied Green Building Consultant, CTG Energetics, Inc. May 28 2010

Non-potable waterPotable water meets or exceeds EPA's drinking water quality standards and is approved for human consumption by the state or local authorities having jurisdiction; it may be supplied from wells or municipal water systems. does not contribute to WEp1. Option 1 under WE credit 2 (Innovative Wastewater Technologies) awards the use of non-potable water in toilets and urinals.

Karen Blust replied Green Building Consultant, CTG Energetics, Inc. Jun 04 2010

Please note that the USGBC is working on revised guidance regarding this particular issue. Stay tuned to the USGBC website for a Water Guidance document that may provide additional clarification.

Karen Blust replied Green Building Consultant, CTG Energetics, Inc. Jun 04 2010

I would consider dormitory lavatories as 'residential', not 'commercial'.

Rick Gehrke replied Consultant, A.C.E. AmBiental Jun 08 2010

Wouldn't that 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.?

Ben Koenig replied Gensler Jun 08 2010

Not Sure if it helps, but there is a 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 on kitchen sinks, that only hand sinks/faucets need to be included in the calculation, and not commercials sinks like potfillers or for washing vegetables. I would think an exam room sink would also fall under commercial sinks and would be excluded from the calc. Is that sink primarily for washing hands or for special uses like washing specimens etc. If for washing hands than you probably should include it and it would fall under public lav faucet in my opinion.

Ben Koenig replied Gensler Jun 08 2010

are you using rainwater or graywater1. Defined by the Uniform Plumbing Code (UPC) in its Appendix G, titled "Gray water Systems for Single-Family Dwellings," as "untreated household wastewater which has not come into contact with toilet waste. Grey water includes used water from bathtubs, showers, bathroom wash basins, and water from clothes-washer and laundry tubs. It shall not include wastewater from kitchen sinks or dishwashers." 2. The International Plumbing Code (IPC) defines graywater in its Appendix C, titled "Graywater Recycling Systems," as "wastewater discharged from lavatories, bathtubs, showers, clothes washers, and laundry sinks." Some states and local authorities allow kitchen sink wastewater to be included in graywater. Other differences with the UPC and IPC definitions can probably be found in state and local codes. Project teams should comply with the graywater definitions as established by the authority having jurisdiction in their areas.?
I used the NC2.2 template and it only changes the percentage if I also enter rainwater and keep it the same in both cases. Otherwise the percentage seems to stay the same with 0 gallons of makeup water. This would make sense.

Annette Bellafiore replied Jun 09 2010

That would make sense, but we're not using any rain/gray water for this project. Thanks though.

Josephine de Montmarin replied Communication and Development Officer, MANEXI Jun 16 2010

Hello Tatjana,

I'm in France and had the same issue. I converted all the standard flow rates into litres (1 gallon = 3,78541178 Litres) to use as my reference rates.
Then I converted psi to bar: 60psi is 4 bar and 80psi is 5.5 bar.
I asked the manufaturer or provider for the flow graphs for each fixture. They show the flow rates from 1 to 5 (or 6) bars, which allows me to verify that the flow rates are respected at either 4 or 5.5 bars, depending on the fixture.

Of course, once you have determined that you are within the water use limits, you have to reconvert all you flow rates fom L/min into gallons to complete the form.

It's a bit tedious, but the equivalencies are there. What is important is to make sure you are calculating the flow at 4 and 5.5 bars since they are the reference for LEED, even if it is not the standard pressure for Germany (France is 3 bar as well).

I hope that helps. And if you come up with a simpler solution, I will be happy to hear of it!

Good luck
Josephine

Josephine de Montmarin replied Communication and Development Officer, MANEXI Jun 17 2010

What is "private" and "public" is not the building itself, but the use of the facilities. The office building itself is most certainly private as far as its ownership is concerned. The facilities, however, are most likely to be considered "public" use.

Private-use facilities: bathrooms in houses/appartments, hotels, hospitals, and commercial establishments where they are used by a family or one individual (for ex: if your boss has his/her own private bathroom in the office...)

Public facilities: bathrooms used by employees, visitors, transient occupants, etc. in commercial, retail and office buildings.

If you are unsure, the recommended path is to default to public-use flow rates.

Josephine

Tristan Roberts replied Editor – LEEDuser, BuildingGreen, LLC Jul 09 2010

Check out Jason Franken's explanation of the terminology on the EBOM WEp1 forum. He does a great job of explaining this terminology.

Tatjana Ernst replied Dipl.-Ing. , Scholze Consulting GmbH Jul 20 2010

Hi everyone,

i got this email from USGBC:

"Even though a company using the fixtures in a commercial office building may be privately-owned, that does not mean that the 'private' lavatory flow rate baseline should be used. As noted on page 174 of the 2009 Edition of the LEED Reference Guide for Green Building Design and Construction (GBDC), �Facilities in residences and apartments, private bathrooms in hotels and hospitals, and restrooms in commercial establishments where the fixtures are intended for the use of a family or an individual are considered private or private-use facilities.� All other facilities are considered public and if in doubt you should default to the public-use flow rate baselines. Most fixtures in commercial office buildings would be considered 'public' for WE calculation purposes."

Allison Zuchman replied Green Building Consultant, Fore Solutions Jul 07 2010

I worked on an ice arena project with a similar scenario, it was filled to peak capacity only a few times a year (though it was a much smaller arena than your Soccer Stadium). For the daily number of visitors, I calculated an average over the number of days that the arena was open per year (so your daily average would be much less than 45,000). I explained in my LEED submission why the daily average number of visitors was significantly less than the peak capacity. Though I do not recall any official USGBC/GBCI protocol to this scenario, my explanation was accepted (LEED NC 2.2 certification). If you want a definite answer, you could submit a 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.

Jean Marais replied b.i.g. Bechtold INGENIEURGESELLSCHAFT MBH Jul 07 2010

This credit is concerned with the yearly potable waterPotable water meets or exceeds EPA's drinking water quality standards and is approved for human consumption by the state or local authorities having jurisdiction; it may be supplied from wells or municipal water systems. consumption. Therefore if you can sketch a good approximation of yearly water use via yearly water use 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., you could approximate the annual water use and savings against the baseline. The calculations actually cancel out the actual consumption inherently, and the credit only concerns itself with the % improvement (the male/female ratio is however important), not the actual water usage in gallons. Further, LEED requires building conditions as per the life time of the building and specifically excludes event based calculations (See MPRs).

If you would like information on how the calculations were done for Stadium Manaus, then you should contact gmp Architects in Berlin, Germany.

Allison Zuchman replied Green Building Consultant, Fore Solutions Jul 07 2010

Jean is correct - you will account for the events, but by averaging the peak out over a typical full year of occupancy.

Rick Gehrke replied Consultant, A.C.E. AmBiental Jun 29 2010

Wouldn't that fall under tenant guidelines?

Allison Zuchman replied Green Building Consultant, Fore Solutions Jul 07 2010

I recommend including the cafe space in the water use calculation so the total water use is more accurate - otherwise your water savings will be inflated. Since you do not know the actual fixtures that will be installed choose the same basic fixture for both the base case and design case so you are not claiming any water savings on those fixtures. If you do not know the actual occupancy of the space yet, estimate 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. based on the maximum occupant load of the space (based on Fire Code for example).

Yes, as Rick mentions, you could also include requirements (or suggestions) for water efficient fixtures in tenant guidelines.

Allison Beer McKenzie replied Architect/Director of Sustainability, SHP Leading Design Jul 13 2010

I have not documented the use of autocontrol faucets on a LEED 2009 project yet, but in NC2.2 and Schools 2007, I would always use 15 seconds for the baseline and 12 seconds for the performance case sensors that had the sensors.

Tristan Roberts replied Editor – LEEDuser, BuildingGreen, LLC Jul 13 2010

Allison, I would recommend reading USGBC's supplemental guidance on WE credits.

Jens, USGBC's guidance is a bit confusing and counter-intuitive, but everything in there is fully intentional and should be followed.

Allison Beer McKenzie replied Architect/Director of Sustainability, SHP Leading Design Jul 13 2010

Tristan- I see what you're referring to in the supplemental guidance. However, I still think it's weird to use 12 for both baseline and design case. The reference guide clearly talks about taking advantage of water savings seen from using sensors, but if this calculation methodology is used, you will not receive ant "credit" for the savings. Are you aware of any sort of reasoning behind this?

Tristan Roberts replied Editor – LEEDuser, BuildingGreen, LLC Jul 13 2010

I think this is simply part of the raising of the WE bar that occurred for LEED 2009. They've really made it hard to get any appreciable savings from lavatory faucets, forcing teams to look deeper for savings.

Allison Beer McKenzie replied Architect/Director of Sustainability, SHP Leading Design Jul 13 2010

I'll buy that. The new .5 gpm baseline for public lavatories is a killer!

Tristan Roberts replied Editor – LEEDuser, BuildingGreen, LLC Jul 20 2010

I read this the same way, and it's quite a big change. I'm looking into it to see if I can learn more. It's curious that the "Implementation" section of the Reference Guide was revised but "collecting rainwater" was retained as a possible strategy. An oversight?

Susann Geithner replied LEED Project Manager, HSB Architects & Engineers Jul 21 2010

There are some other small but probably important changes under the prerequisite. They removed the word "potable" in the section Environmental Issues and under Implementation, they changed "water conservation" to "water efficiency".

Tristan Roberts replied Editor – LEEDuser, BuildingGreen, LLC Jul 24 2010

Susann, there's been some discussion on this topic on another LEEDuser forum about the addenda that helps clarify this issue.

Karen Blust replied Green Building Consultant, CTG Energetics, Inc. Jul 28 2010

A 1:1 male to female ratio is the standard calculation methodology and is applicable in most cases. If project specific conditions exist to justify different usage rates, a narrative should be provided describing these conditions and any special calculation methods used for the project.

Tristan Roberts replied Editor – LEEDuser, BuildingGreen, LLC Jul 28 2010

Leslie, it seems like the nonstandard approach is justified in this case, but since it's non-standard you might want to think about whether it's worth potentially raising an eyebrow in your review. In the LEED Online template, put in the ratio one way and then the other and see if it has a significant impact on your savings percentage.

Leslie Jones replied Interior Designer, FOX Architects Jul 28 2010

Great, Thank you. It's the eyebrow raising I'm trying to avoid.

Tristan Roberts replied Editor – LEEDuser, BuildingGreen, LLC Aug 03 2010

Yes, it is.

Tristan Roberts replied Editor – LEEDuser, BuildingGreen, LLC Aug 04 2010

Scott, your question sounds like it relates to a LEED-CI project, but you're posting here on the LEED-NC forum. If I'm right about that, can you re-post under the LEED-CI WEp1 forum?

Tristan Roberts replied Editor – LEEDuser, BuildingGreen, LLC Aug 29 2010

I haven't been in this boat, but GBCI generally seems consistent in not allowing rounding up.

I would double-check your inputs and make sure there's not a way to get to 35%. Since the LEED Online form won't register the three points, you could enter a narrative under the alt compliance path section and, um, beg for the third point. Might not hurt.

Erik Turner replied Mechanical Engineer, Robison Engineering Aug 20 2010

For a bathroom faucet, you are OK with aerators. The first sentence under "Implementation" in the v3 Reference Guide states:

"Effective ways to reduce water use include installing flow restrictors and / or reduced flow aerators on lavatory, sink, and shower fixtures..."

I've seen some comments regarding aerators not being appropriate for residential sinks. The thought is people will just take them off. Another item to consider is that any use where you have a fixed volume of water (janitor filling up bucket) it doesn't matter the flow rate, they are going to fill up the bucket, and possibly be angry at the person who specified a low flow fixture...

Nelina Loiselle replied Aug 23 2010

Thank you for the feedback Erik! We are planning to put one on a office galley kitchen sink, do you think that will fly or should I not count on it?

Tristan Roberts replied Editor – LEEDuser, BuildingGreen, LLC Aug 29 2010

I would think it would fly. I don't think of office kitchen sinks as being used for filling pots, and as Erik points out, aerators are a recommended strategy.

Karen Blust replied Green Building Consultant, CTG Energetics, Inc. Aug 17 2010

It is possible that there is a flaw in the form, but it is most likely an issue relating to BETA Forms. Are you using the most up-to-date LEED Credit Forms for PIf3 and WEp1? If not (or if you’re unsure), this link provides guidance on the issue and how to resolve it:

https://www.leedonline.com/irj/go/km/docs/documents/usgbc/leed/config/co...

If the Forms you are using are up-to-date, my best advice would be to contact the GBCI via the “feedback” link at the top of the project homepage or under the Credit Information tab within the credit page.

Tristan Roberts replied Editor – LEEDuser, BuildingGreen, LLC Aug 29 2010

Do you mean for the baseline? LEED doesn't specify any specific flow rates for a compliant building, only the baseline case, for sake of comparison.

The showerhead baseline is 2.5 gpm.

V Miller replied WSP Aug 30 2010

Yes, I am enquiring about the the baseline for a non-residential project, which is not inlcuded in the chart in the reference guide. Is it your understanding then that for a showerhead in a hotel, gym, office or other non-residential use, the basline for a residential showerhead (2.5 gpm) should be used?

Tristan Roberts replied Editor – LEEDuser, BuildingGreen, LLC Aug 30 2010

Yes, that's correct.

Jean Marais replied b.i.g. Bechtold INGENIEURGESELLSCHAFT MBH Aug 27 2010

Why is a student defined as a transient? See Table 2a. Non-residential Default Fixture Uses, by Occupancy Type

Karen Blust replied Green Building Consultant, CTG Energetics, Inc. Aug 30 2010

Students are assumed to be transients in NC 2009 because in most higher-education projects, students only occupy the building for several hours per day. If this does not make sense for your project, you can log your student occupancy as FTEs instead of transients and explain your rationale in a narrative.

Karen Blust replied Green Building Consultant, CTG Energetics, Inc. Aug 30 2010

Under the Fixture Family column, simply select the fixture type from the drop down menu for each line item. For flush fixtures, choose between water closet or urinal; for flow fixtures, choose between private lavatory, public lavatory, kitchen sink or shower. By choosing an option from the drop down menu, a baseline water use case is determined.

Robert Hink replied Sep 02 2010

Not the Fixture Family Column.
Far left column, under 'Fixture Groups', there is a 'Select' column.
What if anything goes in that column?
(The form I am looking at is not Beta.)
The form does give a 'Y' if it is blank. But what is it for?