CS 2009 WEp1: Water Use Reduction—20% Reduction

I noticed samething that WEpr1 & Cr 3 has nothing to do with grey water. The key steps above seems to consider grey water in calculation. A bit confused. Am I missing anything?

Vivien,

I would not reccomend "tricking" the template. The form is asking how much water is used and does not consider what type of water. Even if it is 100% rainwater (which is fantastic!) you're still using that water so conservation is important. 

I would suggest selecting the "Alternative Compliance Path" in the form and then providing a narrative describing your strategies.

Thank you - I also just foundthis additional water guidance that has been recently updated http://www.usgbc.org/ShowFile.aspx?DocumentID=6493

I can document the calculations as a narrative - but this won't take account of the points actually achieved by using rainwater to achieve >40% - how should i document this on the template so that it takes account of the 4 points in its calculations without - entering 0 as the flush volume?

The LEED online template will not show it correctly. You will sumit your documentation under alternative compliance path. You than also note this under WE c3, so the reviewer sees that you are using rainwater. This is what we did in a recent project and it's also what the GBCI recommended to do.
Also make sure to show that the precipitation and tank size are working throughout the year to cover the water demand of your fixtures.

Caroline, yes, that should be sufficient. That is a common approach in LEED-EBOMEBOM is an acronym for Existing Buildings: Operations & Maintenance, one of the LEED 2009 rating sytems..

Jukka, I would assume that this approach is not acceptable for LEED. In other cases I have seen that if there is any variation in the flow of a fixture, GBCI assumes (reasonably so, I think) that the maximum flow will be used.

Maria,

The .5 GPM for public lavatory faucets used to be 1.5 GPM way back in NC v2.2. It was updated to .5 GPM based on the American Society of Mechanical Engineers standard. This standard was incorporated into the national Uniform Plumbing Code and International Plumbing Code. Follow this link to learn a little more about the history - http://www.allianceforwaterefficiency.org/Faucet_Fixtures_Introduction.aspx

In terms of duration of a lavatory faucet I see that Table 3a. Non-residential Default Fixture Uses by Occupancy Type was updated by addenda on 2/2/2011. So if you registered your project before 2/2/11 you have the option of using the 30 second duration (12 seconds if autocontrol). Projects registered after 2/2/2011 must use the updated duration times.

Hope this helps.

Thank you John
I hadn’t realized that 0.5 GPM is code in the US. In my country the common belief is that water is something we don’t have to save because we have lots of it. Which I don’t think is a good way of seeing it. It still costs a lot of energy to heat and to treat after it’s been used. Swedish code states that flows should be 0.2 l/s (3.17 GPM). I have now however started opening the eyes of my building owners telling them that we can reduce flows significantly, especially in commercial projects. They are very interested. And I am currently testing different taps in our own office bathrooms to see with own eyes how low we can go and still keep a good comfort for our users.
I have a project that for CS is registered early and can use 15 seconds in the calculation. But now I am also doing a CI certification for the tenant in the same building and they are registered later and have to choose 30 seconds. In CI a large part of the credits are dependent on WE. So I really have to think twice already in the CS-project so that the CI-project don’t have to change anything later.

Luis, typically the project’s LEED registration date determines which Addenda, LEED Interpretations and formal guidance documents are applicable to the project. In this case, however, I would recommend following the Water Use Reduction Additional Guidance (updated July 14, 2011) and use a 1.6 gpf baseline instead of the higher blowout fixture baseline. This is the conservative approach and will likely result in a more straightforward review of WEp1.

Thanks Karen! I think we will follow your advice and take a conservative approach.

I have had this same problem on a LEED NC project. I have a jail where we are using 1.6 gpf blowout fixtures. We also registered prior to the issuance of the Water Use Reduction Additional Guidance you referenced. I wrote our reviewer asking if this guidance applied to us given our registration date. I was told that because this document is "Additional Guidance" and not an Addenda that it still applies to my project despite the fact that we registered prior to its issuance. This cost us three points.

However, the approach that Karen suggests will still provide water savings (thankfully you are using 1.27 gpf) and will lower your overall water use (1.6 gpf instead of 3.5 gpf) so that any water saving you have project-wide will likely be a more significant percentage. Though, I would think that this is a more aggressive approach since you will still get water savings from your blow-out fixtures opposed to the zero savings that you would get if you followed the guidance and put both your baseline and proposed at 3.5 gpf.

I don't know if LEED would push back on you submitting a 1.6 baseline, but I would imagine not. You are also already more than IPCInternational Plumbing Code/UPCUniform Plumbing Code compliant with the 1.27 gpf, so you should be ok.

The aggregated consumption is what really counts for this credit. So you can be above 1.6gpm and make up for it with foe instance high efficient faucets. Also if you provided proof for the requirements per building code than the reviewer may let you assume the flow rate for design and baseline case to be equal. Check the LEED Interpretation database for a ruling on this.
In general if this is a code requirement than they let you do this. That's from my experience with other credits.

Joaquim, you can certainly not dismiss that.

I am a bit confused, though—your building was already certified, or is in the process of being certified?

What is in the scope of the CS work? Are you doing fit-outs, or are the tenants? For a better understanding of how to treat fit-outs, see the CS Appendix in the LEED BD&C Reference Guide.

Tristan,
My building is pre-certified as was CS, I am working to gain certification. My building is residential, so each apartment (unit) will have a different owner!

I include in the calculations for the reduction of water these apartments (units)??

Thanks

There is some detail on this that you need to read about the Reference Guide that I mentioned in my last comment. Do you have that?

Maria, I think these restrooms should be called "public." Even though they are not open to the general public, the "private" designation is reserved for something like a restroom in an executive suite where one individual will be using it.

FYI -- this information is located at the top of page 88 in the LEED for Green Building: Operations and Maintenance Reference Guide (2009 Edition).

Maria, I concur with Tristan. The definition of private fixtures are those fixtures dedicated to the use for and by a single person. It sounds like you are describing core bathrooms and these are public because everyone on that floor may use the fixtures.

Below the GBCI response
==============================================
Dear Wagner,

Thank you for contacting the Green Building Certification Institute, and my apologies for the severely delayed response. In regards to your questions concerning WEp1 addenda:

1. Unfortunately the form in LEED Online v3 is not set up to receive different faucet durations. In order to accommodate for the design-case duration for fixtures used on your project, you will need to translate the 12 second cycle into GPC (Gallons Per Cycle) by using the actual fixture flow rate (GPM) and the 12 second duration. For the baseline flow rate, your project team should use the metering baseline of 0.25 GPC. It may be useful to reference our WEp1/WEc3 Guidance Document found here: http://www.usgbc.org/ShowFile.aspx?DocumentID=6493, for additional information on the calculations for this credit.

2. Even for a CS project, your project team will need to use the default fixture-use as outlined in the table on pg. 171 in the reference guide for nonresidential kitchen sinks (1 use 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. for a 15 second duration each) in order to calculate the baseline use for this fixture group within the entire building.

We realize that it may be hard to calculate and accommodate for this credit when occupancy details may be unknown, however, these fixture uses must still be accounted for in the WEp1 calculations. If the project team feels that the default occupancy counts outlined in CS Appendix 1 on page 611 are not accurately representative of their CS project, you may certainly propose an alternative by supplying a detailed narrative describing the basis of your occupancy calculation and ensuring that all occupant types are accounted for (FTE, Transients, etc). However, please also note that the review team still reserves the right to deny this approach if there are any outstanding issues, as Customer Service is not authorized to review or approve alternative compliance approaches outside the LEED certification review process. If you require formal approval outside of the review process, you will need to submit a formal project Credit Interpretation Ruling (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) request via LEED Online (http://www.gbci.org/Certification/Resources/cirs.aspx) with additional details requesting advanced permission to use the alternate compliance approach you have suggested. Only a CIR can verify the validity of a particular approach in advance of your certification review.

3. If the same kitchen sink fixtures are applied in a professional/commercial grade kitchen setting, they will 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. fixtures and will not need to be included in WEp1 calculations for your project. This would also include pre-rinse spray fixtures. For more information, please reference LI #5291 and #1866 (which may be relevant to your situation) in our LEED Interpretation database found here: https://www.usgbc.org/leedinterpretations/lilanding.aspx.

I hope this information proves helpful. If you have any further questions or concerns, please feel free to use the contact form at http://www.gbci.org/contactus or call us at 1.800.795.1746. Thank you.

Best Regards,

Jarrod

Green Building Certification Institute
2101 L Street NW, Suite 500
Washington, DC 20037
800-795-1746 (phone)
202 828-5110 (fax)
www.gbci.org/contactus

Lauren, are you familiar with CS Appendix 4 from the LEED Reference Guide? I would review that.

To your point, zero plumbing fixtures = 100% reduction only if the CS bulding remains a shell. If that's the case then it should be NC, not CS. Since it is built with the intention that it will be occupied and water will be used, LEED wants you to have some controls in place to ensure that water is used efficiently.

Does that make sense?

Tristan,
Thank you for your response. I think I have a better understanding now. I think I got hung up on the name of the Rating System being Core & Shell. After having just finished an NC project, I was expecting more of a differentiation on LEED's part between the two systems. I can appreciate their interest in applying some Prereqs and Credits in a wholistic fashion.

Lauren,

The idea behind LEED, as it had been explained to me, is to provide a quantifiable measurement of a “Green” building/construction project, compared to a standardized baseline.
(Tristan, or any other moderator, please correct me if I am misinterpreting or misrepresenting anything here.)

In the case of WEp1 & WEc3, the quantifiable calculation is the following:
[ { (Annual Water Use in Baseline Building) - (Annual Water Use in Design Building) }
/ (Annual Water Use in Baseline Building) ] x 100 = Annual Water Use Percent Savings

If the Annual Design Water Use is 60,000 Gal, and the Annual Baseline Water Use 100,000 Gal, then your savings would be the following:
[ { (100,000) – (60,000) } / (100,000) ] x 100 = 40% Savings

Or if the Annual Design Water Use is 0 Gal, and the Annual Baseline Water Use 100,000 Gal, then your savings would be the following:
[ { (100,000) – (0) } / (100,000) ] x 100 = 100% Savings

However, if the Annual Design Water Use is 0 Gal, and the Annual Baseline Water Use 0 Gal, then your savings would be the following:
[ { (0) – (0) } / (0) ] x 100 = Undefined Savings

If you have no basis of comparison, there can be no quantifiable measurement of savings, or level of “green”. GBCI does not want to permit loopholes that allow building owners/developers to build a shell and call it “LEED Certified” by claiming the tenant will add insulation, ventilation, high efficiency HVAC, low flow plumbing, day-lighting, etc. However, GBCI does allow for options if an owner/developer chooses to build a shell. GBCI has included the provisions to allow the project to attain LEED Certification IF the owner/developer can provide a legally binding and enforceable lease agreement mandating that the tenant meet all of the requirements claimed by the owner/developer in the LEED CS certification process.
The owner must provide the core, in addition to the shell, that meets the LEED requirements, or mandate that the tenant provide an adequate core to meet the LEED requirements. But a core and shell must both be provided to attain LEED for Core and Shell certification.

I refer back to my statement that an owner cannot purchase an empty lot and claim it is a LEED Platinum Building.

I hope this helps you to explain intention of the guidelines to the owner/developer in this case.

Thanks,
Tony

To follow up with a couple questions, as I am used to NC, not CS:
1) Dumb question first. Where is Appendix 4? (the tenant/lease agreement) It's not in the CS book appendices or the recent CS May update PDF; is it a separate download buried in the USGBC website somewhere?
2) I am building out a space with 90% of fixtures provided, but some future tenants will select their own fixtures. Further down this page, on July 14 2010, a comment says fixtures not in the project scope should not be included. This thread indicates that I need an agreement on the remaining 10% of fixtures. Which is it, and if I don't get an agreement in place, can I assume that the remaining 10% of fixtures are equal in the baseline and proposed cases? (worst-case scenario)
3) My project is CSv2.0, where there is no WE prereq. I would think even if I had no fixtures as part of the scope, I could just pass on those points and be OK, which points me towards the July 2010 method of analysis.

Thoughts?

Curt,

Appendix 4 is in the back of the LEED 2009 (v3) Green Building Design and Construction Reference Guide. I'm not sure that this appendix was included, or if this option was available, in LEED CS v2.0.
And I don't want to comment on the second part of your question, because I'm not as familiar with the CS v2.0 Reference Guide. I'll leave that to someone more knowledgeable. Hope that helped a little!

Thanks,
Tony

Ah, perfect thank you. Can't believe I didn't check the 2009 books. Yes, Tenant Guidelines are available in CSv2.0 and referenced in the guide, but App. 4 appears to only exist for CSv2009.

Alessio, faucet aerators are definitely allowed for WEp1/c3.

You are correct. LEED-CS v2.0 does not provide a blow-out fixture baseline. The project may attempt to use the 3.5 gpf baseline listed in the 2009 Reference Guide, but I would recommend submitting a LEED Interpretation to the GBCI in order to get clear direction on how to document the project’s water use reduction with this specific fixture.

I don't recall where I have seen that, but NO you can't use that to reduce your consumption for LEED. Essentially your local supplier extracts water from the ground and supplies it to you. This would be you cutting out the supply portion but still using the same resource. It's different if you would treat the water, like rain water, to use it as 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..

Fabiano, you may just have to make it up! Does the client have any idea what the transient population will be?

As far as I can tell from CS Appendix 4, you need to include the tenant spaces in your calculations. See more in the BD&C LEED Reference Guide.

I have done a couple of LEED CS projects and Tristan is right, you will have to include the tenant's use. If you do not require them to reduce the use, you will have to assume it to be baseline. So without actually any influence on the tenants build-out you will have a very hard time to meet the 20% reduction.

The lavatory is a regulated fixture and would be counted but a bidet is not counted.

Thanks again Tristan,

The rules for WEp1 are demanding, but M&V does not cover the water usage and the real usage could be quite different.

George, due to the controlled access they sound "private" to me.

thanks Tristan !

Which sample form are you referring to? One you downloaded from LEED Online?

I downloaded the dynamic Core and Shell WEp1 sample form from LEED Online and filled out the form. The result was 21% reduction of water use in all fixtures and "N".

I'm not totally sure those forms are meant to be fully functional. For example, an upload is required to document the credit, but that form will not recognize an upload. The point of the forms is to provide an understanding of how to document the credits, not to actually document them. Make sense?

Thanks Tristan,
I hope it works, when we actually document the credit. Some other sample forms worked fine and showed the points or "Y".

The WEp1 sample form seems to be fully functional after all. You need to type something in the box "Fixture Groups Definition" and the "N" changes to "Y".

For all other fixtures?

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 to see if based on the code requirements there is some way around the prerequisite.

However, the surest way would be the use rainwater, etc., to substitute for 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. demand.

Thanks Tristan, we may just 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, since Water Efficient Landscaping points would be easy here with no shortage of fresh water, if we get around the prerequisite. Minimum flow for all other fixtures, except toilets and urinals is over the baseline in local code. That keeps the sewer lines healthy.

The USGBC posted a 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

Have you checked this out?

I think this is unlikely to be accepted, on the basis that the fixture could easily be adjusted to the higher rate by an occupant or maintenance person.

We are running into this issue a lot. Tristan, I appreciate your comment and logically think this is correct but was wondering if anyone had anything explicitly confirming or denying this approach. Our client is really pushing us on this right now and I can't find anything solid to base my response on. Logic isn't enough for him.

Thanks again.

Will occupants be able to adjust the fixture to the higher flow rate? If that's possible, it's likely—and I really, really doubt that USGBC would accept the lower flow rate. I"ll see if anyone else has experience on this, though.

There is no specific guidance published by the USGBC related to adjustable volume flow rates. I would agree with Tristan in that the lower flow rate would not be accepted by the GBCI. The GBCI/USGBC typically goes with the worst-case scenario in cases where ranges are provided. As such, if you submit an adjustable flow rate fixture, you’ll have to input the highest flow rate in your water use calculation.