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The bar has been raised
You will not earn this prerequisite using standard fixtures that only comply with the federal EPAct 1992. This prerequisite, first introduced in LEED 2009, raises the bar significantly. All projects must now reduce water use by at least 20% as a prerequisite, whereas earlier versions of LEED awarded a point for a 20% reduction. The baseline against which water savings are measured 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. Note that this prerequisite addresses interior water use only, but can be coupled with other water credits addressing outdoor water use.
Plan on focusing on efficiency with ultra-low-flow or waterless fixtures, as well as overall conservation with strategies like rainwater capture and graywaterGraywater is untreated household waste water which has not come into contact with toilet waste. Graywater typically includes used water from bathtubs, showers, bathroom wash basins, and water from clothes-washer and laundry tubs, though definitions may vary. Some states and local authorities also allow kitchen sink wastewater to be included in graywater. Project teams should comply with the graywater definition established by the authority having jurisdiction in the project area. reuse (these strategies are documented as an alternative compliance path in LEED Online). Careful attention to fixture selection and flow rates can help projects achieve 20% or greater interior water savings at minimal cost and without compromising comfort.
Follow these key steps
- Determine Full Time Equivalent (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.) occupancy and Fixture Usage Groups.
- Determine the Baseline Case Water Use Budget for Indoor Water Use.
- Choose fixtures and water reduction or reuse strategies.
- Estimate the project’s water usage by creating a Design Case Water Use Budget.
- Use the LEED Online credit form to compare the baseline and design case water budgets to determine the water reduction percentage for the project.
- Complete the LEED Online credit form and upload water fixture cut sheets.
In the example illustrated in this bar chart, 21% savings is achieved by looking for savings in the fixtures that use the most volume of water: toilets, urinals, and showers. This example assumes 1.28 gpf toilets, 0.5 gpf urinals, and 2.0 gpm showers. Sinks are a less likely target because baseline use is already very low in many cases.
Only some water uses are under the LEED scope
Project teams often assume that if a water fixture or process on their project uses water, then it must fall under the scope of this credit. However, only specific "regulated" fixtures fall under the scope. The following uses, among others, are not within the credit scope. Following efficient practices is a great idea for these uses, but it's simply not covered under the scope here.
- "Process" water
- Pot- or bucket-filling sinks
- Bidets
- Laboratory sinks
- Dishwashers and other appliances
Key guidance from USGBC
Since LEED 2009 was launched, USGBC has developed and updated a key guidance document for WEp1 calculations: Water Use Reduction Additional Guidance. It provides indispensable guidance for fixture groups, total daily uses calculation, dual flush toilet flow rates, public metering faucet flow rate conversion, 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 alternative compliance path and gender ratio guidance.
For example, this document provides key guidance on when a non-default male-female gender ratio is appropriate—essentially, modifications to the 50:50 ratio must be shown to apply for the life of the building, with specific exceptions allowed.
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A question of scope
As of an addenda issued in May 2011, USGBC has clarified the scope of this prerequisite for addition projects. For additions to existing buildings, only the fixtures within the project scope must be counted for WEp1. To earn points under WEc3, all fixtures necessary to meet the needs of occupants using the addition must be included, including those located within the preexisting building.
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FAQs for Water Use Reduction
Will the reviewers accept a spreadsheet as a plumbing fixture schedule in lieu of the plans from the Construction Documents?
A copy of the plumbing fixture schedule from the project's construction documents, outlining detailed information for each flush and flow fixture specified (including fixture manufacturer, model number and flow rate) helps the review team verify that those fixtures are part of the construction contract. In the absence of such documentation, a copy of project-specific specifications and details or a project-specific contractor’s submittal with manufacturer’s cut sheets highlighting flush and flow rates for each fixture specified can be provided.
In LEED review comments I've been referred to the Water Use Reduction Additional Guidance document. I didn't know this was a required reference document.
USGBC originally created this guidance document to address common questions project teams encountered when documenting WE credits. The calculations in these forms are fairly complex and are generally not addressed in the reference guide. The guidance document is intended to guide the user through the process of filling out the form, but is not intended to create any new requirements.
Should I include bar sinks? What about mop sinks or janitor sinks? Swimming pools? Safety showers? Bidets? Tub spouts?
If the bar sinks installed have a similar usage pattern and are similar fixture type as for those in kitchens then these should be included.
Mop sinks, janitor sinks, swimming pools, bidets, and safety showers are 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 are not included. Consider only the showerhead and not the tub spout.
Additionally, commercial kitchen sinks and bar sinks including pot sinks, prep sinks, wash down, and cleaning sinks are considered process water and are not included.
However, pre-rise spay valves must be considered. If your project is registered after the 11/1/2011 addenda release then the pre-rinse spray valve flow rate must be 1.6 gpm or less in order to comply with the prerequisite. If your project has a pre-rinse spray valve that has a higher flow rate than 1.6 gpm, then the project is not in compliance and the pre-rinse spray valve would need to be revised in order to be eligible for LEED certification.
We provided showers to comply with the alternative transportation credit. Should they be considered in WEp1 calculations?
Yes. Once you enter the project occupancy the WEp1 form calculates the default daily FTE shower uses.
If those fixtures are outside the LEED Project Boundary, they should only be included if your project is LEED-CI, however.
Can you explain the 12-second duration for metering faucets?
This duration is intended to prevent LEED projects from claiming credit for reducing the duration below 12 seconds; durations less than 12 seconds are not permitted for LEED calculations as shorter intervals are insufficient for typical hand washing
Can I use a nonpotable water source to contribute to WEp1 compliance?
Yes. Although the focus is water efficiency of the installed fixtures, onsite sources of nonpotable water such as captured rainwater, graywaterGraywater is untreated household waste water which has not come into contact with toilet waste. Graywater typically includes used water from bathtubs, showers, bathroom wash basins, and water from clothes-washer and laundry tubs, though definitions may vary. Some states and local authorities also allow kitchen sink wastewater to be included in graywater. Project teams should comply with the graywater definition established by the authority having jurisdiction in the project area., air conditioner condensate, cooling tower bleed off water, etc., can be applied via an alternative compliance path. Refer to the Water Use Reduction Additional Guidance document for further information.
Our project does not have any eligible water fixtures in the project boundary. Can we comply with WEp1?
Yes, per LEED InterpretationLEED Interpretations are official answers to technical inquiries about implementing LEED on a project. They help people understand how their projects can meet LEED requirements and provide clarity on existing options. LEED Interpretations are to be used by any project certifying under an applicable rating system. All project teams are required to adhere to all LEED Interpretations posted before their registration date. This also applies to other addenda. Adherence to rulings posted after a project registers is optional, but strongly encouraged. LEED Interpretations are published in a searchable database at usgbc.org. #10214: "A project without eligible water fixtures in the LEED-NC project boundary is exempt from WEp1. Should such a project wish to pursue points under WE Credit 3, they may do so by evaluating WEc3 performance based upon all of the fixtures that are necessary to meet the needs of the project occupants, even if they are located outside the project boundary."
We are having trouble finding EPAct-compliant fixtures. Is that a problem?
Not for individual fixtures. You only have to meet the LEED requirements for your fixtures as a group.
Where can I find a clear meaning of "public" and "private" as relevant to lavatory faucets?
Private usePrivate use applies to plumbing fixtures in residences, apartments, and dormitories, to private (non-public) bathrooms in transient lodging facilities (hotels and motels), and to private bathrooms in hospitals and nursing facilities. applies to plumbing fixtures in residences, apartments, and dormitories, to private (non-public) bathrooms in transient lodgingLodging are facilities that provide overnight accommodations to customers or guests, including hotels, motels, inns and resorts. facilities (hotels and motels), and to private bathrooms in hospitals and nursing facilities. Any fixtures that are not in one of those more residential-focused situations are considered to be public fixtures.
Our project is a factory with historically a 95% male workforce. The restroom design accounts for this. Can I argue that the male/female gender ratio is different than 50/50?
LEEDuser has seen numerous comments on our forums suggesting that reviewers are providing little leeway for situations like this, even in a case just like you describe. Even a 10% bump toward women to account for possible future trends was not deemed sufficient. At this point (February 2013), LEEDuser is not aware of clear guidance on when a nonstandard gender ratio would be accepted, nor are there any applicable LEED Interpretations for LEED 2009 projects. If you have any relevant experience on this, please let us know!
Are shower duration controls an acceptable water-saving strategy?
LEED assumes a baseline of 300 seconds for a shower, and LEEDuser has heard of review comments rejecting controls that would shorten this duration for the design case. 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 or LEED Interpretation would likely be needed to make a case.
Can I include process water savings in order to earn an Exemplary Performance point?
Yes—refer to LEED Interpretation #5819, issued 8/31/2004 and modified 4/1/13 to apply to NC-v2.2 and NC-v2009 projects. Quoting the relevant text from LI #5819: “A whole building approach to process water must be used (including washing machines, dish washers, drinking fountains, cooling towers, etc.) The project must demonstrate a process water savings that is equal to or greater than 10% of the regulated water usage as calculated in WEc3. The project should obtain information on the average amount of water use for each type of equipment to determine an appropriate baseline and demonstrate that the increased efficiency compared to the baseline exceeds the 10% WEc3 threshold. Required submittals for this innovation would include: 1) A narrative explaining what strategies were used and how the baseline was developed. 2) Calculations demonstrating performance compared to the baseline. 3) Cut sheets showing water usage of equipment used.”
NC projects have also had success using Schools WEc4 as an ID credit. Also see LEED Interpretations #808 (issued 7/8/2004) and #5752 (issued 5/13/2005) for some history on this issue. You can also earn an EP point for 45% savings under the Water Use Reduction credit, but it appears, based on the most recent ruling, that the 45% savings should be based on regulated (non-process) fixtures alone.
Legend
- Best Practices
- Gotcha
- Action Steps
- Cost Tip
USGBC
Excerpted from LEED 2009 for Core and Shell Development
WE Prerequisite 1: Water use reduction
Required
Intent
To increase water efficiency within buildings to reduce the burden on municipal water supply and wastewater systems.
Requirements
Employ strategies that in aggregate use 20% less water than the water use baseline calculated for the building (not including irrigation).
Calculate the baseline according to the commercial and/or residential baselines outlined below1. Calculations are based on estimated occupant usage and must include only the following fixtures and fixture fittings (as applicable to the project scope): water closets, urinals, lavatory faucets, showers, kitchen sink faucets and pre-rinse spray valves.
Commercial Fixtures, Fittings, and Appliances Current Baseline (Imperial Units) Current Baseline (Metric units) Commercial Toilets 1.6 gallons per flush (gpf)*
Except blow-out fixtures: 3.5 (gpf)6 liters per flush (lpf)
Except blow-out fixtures: 13 lpfCommercial Urinals 1.0 (gpf) 4 lpf Commercial Lavatory (Restroom) Faucets 2.2 gallons per minute (gpm) at 60 pounds per
square inch (psi), private applications only (hotel
or motel guest rooms, hospital patient rooms)
0.5 (gpm) at 60 (psi)** all others except private
applications
0.25 gallons per cycle for metering faucets8.5 liters per minute (lpm) at 4 bar (58 psi),
private applications only (hotel or motel guest
rooms, hospital patient rooms)
2.0 lpm at 4 bar (58 psi), all others except
private applications
1 liter per cycle for metering faucetsShowerheads 2.5 (gpm) at 80 (psi) per shower stall **** 9.5 lpm at 5 bar (58 psi) For projects with commercial pre-rinse spray valves, the flow rate must comply with the asME a112.18.1 standard of 1.6 gpm or less.
Residential fixtures, fittings, and appliances Current baseline (imperial units) Current baseline (metric units) Residential toilets 1.6 (gpf)*** 6 liters per flush (lpf)
Except blow-out fixtures: 13 lpfResidential lavatory (bathroom) faucets 2.2 (gpm) at 60 psi 4 lpm
8.5 lpm at 4 bar (58 psi), private applications only
(hotel or motel guest rooms, hospital patient rooms)
2.0 lpm at 4 bar (58 psi), all others except private
applications
1 liter per cycle for metering faucetsResidential kitchen faucet Residential showerheads 2.5 (gpm) at 80 (psi) per shower stall**** flow rate ≤ 6.1 lpm
(no pressure specified; no performance requirement)* EPAct1992 standard for toilets applies to both commercial and residential models.
** in addition to Epact requirements, the american society of Mechanical Engineers standard for public lavatory faucets is 0.5 gpm at 60 psi (2.0 lpm at 4 bar (58 psi)) (asME a112.18.1-2005). this maximum has been incorporated into the national uniform plumbing Code and the international plumbing Code.
*** EPAct 1992 standard for toilets applies to both commercial and residential models.
**** residential shower compartment (stall) in dwelling units: the total allowable flow rate from all flowing showerheads at any given time, including rain systems, waterfalls, bodysprays, bodyspas and jets, must be limited to the allowable showerhead flow rate as specified above (2.5 gpm) per shower compartment, where the floor area of the shower compartment is less than 2,500 square inches (1.5 square meters). for each increment of 2,500 square inches (1.5 square meters) of floor area thereafter or part thereof, an additional showerhead with total allowable flow rate from all flowing devices equal to or less than the allowable flow rate as specified above must be allowed. Exception: showers that emit recirculated 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. originating from within the shower compartment while operating are allowed to exceed the maximum as long as the total potable water flow does not exceed the flow rate as specified above.
The following fixtures, fittings and appliances are outside the scope of the water use reduction calculation:
- Commercial Steam Cookers
- Commercial Dishwashers
- Automatic Commercial Ice Makers
- Commercial (family-sized) Clothes Washers
- Residential Clothes Washers
- Standard and Compact Residential Dishwashers
Potential Technologies & Strategies
WaterSense-certified fixtures and fixture fittings should be used where available. Use high-efficiency fixtures (e.g. water closets and urinals) and dry fixtures, such as toilets attached to composting systems, to reduce water demand. Consider using alternative on-site sources of water (e.g. rainwater, stormwater, and air conditioner condensate) and graywaterGraywater is untreated household waste water which has not come into contact with toilet waste. Graywater typically includes used water from bathtubs, showers, bathroom wash basins, and water from clothes-washer and laundry tubs, though definitions may vary. Some states and local authorities also allow kitchen sink wastewater to be included in graywater. Project teams should comply with the graywater definition established by the authority having jurisdiction in the project area. for nonpotable applications such as custodial uses and toilet and urinal flushing. The quality of any alternative source of water used must be taken into consideration based on its application or use.
Technical Guides
Energy Policy Act of 1992 and amendments
Pages 62-69 of this legislation set federal standards for plumbing fixtures.
Energy Policy Act of 2005
The Energy Policy Act (EPA) addresses energy production in the United States. One example, the Act provides loan guarantees for entities that develop or use innovative technologies that avoid the by-production of greenhouse gases.
LEED 2009 Water Use Reduction: Additional Guidance
This document from USGBC offers guidelines to help you properly set up fixture usage groups in the LEED Online credit form, avoiding common mistakes associated with the water-efficiency prerequisite and credit.
Web Tools
WATERGY version 3.0
WATERGY is a spreadsheet model that uses water/energy relationship assumptions to analyze the potential of water savings and associated energy savings.
EPA Water Information links
This website offers links to state and regional water information.
Water Studies
This site provides a number of studies related to water.
Organizations
Alliance For Water Efficiency
AWE advocates for water-efficient products and programs and provides information related to water conservation.
EPA Office of Water
The Office of Water coordinates EPA's efforts to protect drinking water, oceans, watersheds and other aquatic ecosystems.
American Rainwater Catchment Systems Association
This organization promotes rainwater catchment in the U.S.
Oasis Grey Water Policy Center
Oasis Design, a maker of graywaterGraywater is untreated household waste water which has not come into contact with toilet waste. Graywater typically includes used water from bathtubs, showers, bathroom wash basins, and water from clothes-washer and laundry tubs, though definitions may vary. Some states and local authorities also allow kitchen sink wastewater to be included in graywater. Project teams should comply with the graywater definition established by the authority having jurisdiction in the project area. systems, maintains this compilation of graywater laws and other resources on the regulation of graywater use.
Product Cut Sheets
Carefully research products and examine cut sheets to find fixtures and fittings meeting the credit requirements, as shown in these examples.
Samples
Design Submittal
Documentation for this credit can be part of a Design Phase submittal.
WEp1 LEED Online Form
This sample form for WEp1 is from a real project whose name was changed on the form. (Note that WEp1 was achieved for this project even though this sample displays that the form was not completed.)
LEED Online Forms: CS-2009 WE
The following links take you to the public, informational versions of the dynamic LEED Online forms for each CS-2009 WE credit. You'll need to fill out the live versions of these forms on LEED Online for each credit you hope to earn.
Version 4 forms (newest):
Version 3 forms:
- WEp1: Water Use Reduction
- WEc1: Water Efficient Landscaping
- WEc2: Innovative Wastewater Tech.
- WEc3: Water Use Reduction
These links are posted by LEEDuser with USGBC's permission. USGBC has certain usage restrictions on these forms; for more information, visit LEED Online and click "Sample Forms Download."
LEEDuser is produced by BuildingGreen, Inc., with YR&G authoring most of the original content. LEEDuser enjoys ongoing collaboration with USGBC.
159 Comments
Petr, the manufacturer's specifications should be sufficient for documentation. Watersense is not required, and there is no specific testing protocol.
Greywater and WEpr1 Template Calulations
In completing the form for WEpr1, I noticed that there is no way to acknowledge/take advantage of our projects use of greywater. Oh sure WEcr2 allows us to take advabtage of greywater usage. Just seems strange that the WEpr1 calcs does not also include greywater. I am guessing that the logic is that WEpr1 is all about getting design teams to pick lower flow fixtures and reserving WEc2 and WEc3 for design options that reduce/replace 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. with greywater. Your comments and thoughts would be appreciated.
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?
You can use graywaterGraywater is untreated household waste water which has not come into contact with toilet waste. Graywater typically includes used water from bathtubs, showers, bathroom wash basins, and water from clothes-washer and laundry tubs, though definitions may vary. Some states and local authorities also allow kitchen sink wastewater to be included in graywater. Project teams should comply with the graywater definition established by the authority having jurisdiction in the project area. and rainwater to get credit under WEp1 but you have to do it as an alternative compliance path. The focus on the main documentation is on fixture efficiency.
Adjustable valve for WC fixtures
Dear all,
The project has 2/4 LPF WC fixtures specified, and the water calculations done accordingly.
The Contractor is suggesting a WC fixture with a maximum flush rate of 3/6 LPF, but with a regulating valve that can decrease the flush rate down to zero. In other words, the WC fixture can be adjusted to provide 2/4 LPF, but can be easily adjusted later on to a higher non-compliant flow rate.
Has anyone had experience with the USGBC with such types of WC fixtures?
Thanks..
George, I think you might get questioned on a valve that can increase the flush rate, given the likelihood that it could be changed in the future.
Alternative Compliance Path Documentation
I wish to pursue an Alternative Compliance Path for taking account of collected rainwater being used for the toilet and urinal flushing under credit WCp1 and WE3. Should icomplete the template as having 0 flush volume for the WCs and urinals to "trick" the template into Attempting 4 points? as in our case the provision is actually greater than demand. If it was less than 100% i would pro rata this - correct? thanks
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.
Documentation for demonstrating the sanitary fixtures flow rate
Regarding the documentation to demonstrate the sanitary fixtures flow rate, can we submit a test report conducted on-site which can demonstrate the exact flow rate of the sanitary fixtures in our project building, instead of submitting the manufacturers’ data? Some of our sanitary fixtures do not have the product information sheets provided by the manufacturers.
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..
Caroline, how did you go with this? I just had a reply from a reviewer telling me that on-site measurements demonstrating actual flow rates do not comply with the prerequisite.
(We uploaded some cut-sheets with values that are much higher than the ones reported by on-site measurement, but at the end of the day, the actual values are the ones that we had measured).
Tristan, do you know about a certain format that would be approved by the reviewer?
Do you think a measurement performed by the commissioning agent with its report would be sufficient?
Thank you for your quick response.
Preset lavatory faucets
In our project we have possibility to use preset lavatory faucets in which we can adjust preset flow rate. However, user may use temporarily higher flowrate by lifting the tap and after use faucet will return automatically to its preset flowrate.
May we use the preset flowrate in water use reduction calculations?
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.
Duration in lavatory faucets – 15 or 30 seconds?
On LEED Online and in the Reference Guide one use of a lavatory faucet is 15 seconds. In the Water Use Reduction Additional Guidance (updated July 14, 2011) page 3, the duration of a lavatory faucet is 30 seconds. All my projects were registered earlier than July, which duration should I use? Can I use 15 seconds? The precertification comments state that I should use the Additional Guidance (but not what version).
I have also been wondering why a private lavatory faucet has 2.2 GPM for the baseline, while public lavatory faucets have 0.5 GPM. Why is there such a big difference? Why is one allowed to have much bigger flows in private faucets? They look the same and are used in basically the same way.
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.
Blowout Fixtures
Hello Everyone:
The project we are working on is an office building applying for LEED CS. The project will have two "public" restrooms in each floor (men/women). These types of institutional office projects normally use Blow-Out fixtures here in Colombia. That's why we were planning to use Blow-Out Fixtures (3.5 GPF) in our baselimne. That was until we saw this document http://www.usgbc.org/ShowFile.aspx?DocumentID=6493 . It says that when selecting the Blow-Out Fixtures for the baseline, one should also use the 3.5 GPF value in the installed case. It also says, that no credit may be taken from reducing consumption of a Blow-Out Fixture.
In our project we are installing blow-out fixture with a water usage of less than 1.6 GPF (1.27 GPF). What should we do? If we Use 1.6 GPF in the baseline we will loose water saving percentage we were counting on. Does the document applies to our project, since the revision was made after registration? If it does (most probably), should we consider our fixtures as “water closets” instead of blow-out fixtures?
Thanks for the advice
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.
Pre-rinse spray valves
LEED-CS 2009 form WEp1 version 4.0 states the following:
"Note: The flow rate for all pre-rinse spray valves must be less than or equal to 1.6 gpm. If there are multiple fixtures with varying flow rates, insert the highest flow rate."
The local building code requires flow rate that is greater, than 1.6 gpm for pre-rinse spray valves.
How do you solve this problem?
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 InterpretationLEED Interpretations are official answers to technical inquiries about implementing LEED on a project. They help people understand how their projects can meet LEED requirements and provide clarity on existing options. LEED Interpretations are to be used by any project certifying under an applicable rating system. All project teams are required to adhere to all LEED Interpretations posted before their registration date. This also applies to other addenda. Adherence to rulings posted after a project registers is optional, but strongly encouraged. LEED Interpretations are published in a searchable database at usgbc.org. 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.
Interior Construction
Good morning,
My building is a residential building and was certified as core & shell, credit MR - 4 (Recycled Content) there is a paragraph that says interior construction is not part of the Core & Shell project. So my question is whether in WE Prerequisite 1 (Water Use Reduction), I also dismiss the consumption interior construction?
Thank you!
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?
Are the restrooms private or public in an Office Building?
Hello. We are doing a C&S certification for an office building.
Ground floor is commercial basically (therefore the restrooms are public)
Floors 1 to 7 are offices for lease that have on each floor their respective male and female restrooms (3 wcs 3 lav. sinks for female and 2 wcs 3 lav. sink and 1 urinal for male). This restrooms will only be used by the people working on that specific floor. Ej: People working on level 5 will have access to bathrooms in level 5
My question is if they are private or public?
I believe they would be private Since:
1. Only users working on the offices can access them
2. You cant access them from the street, you should get permission from somebody working in the offices or the administration.
Anyone knows? Thanks for your help.
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.
LEED NC & CS v3.0 Quarterly addenda
The latest version of LEED NC & CS v3.0 Addenda incorporates changes and improvements to LEED 2009 resources. However there are some considerations that were not clear. Find bellow some questions:
1 - The latest version of LEED NC & CS v3.0 Addenda, establishes in note with ID number 100000753, the default duration for metering type/autocontrol faucet equal to 15 seconds for the baseline and 12 seconds in design case. However the actual version of WEp1 Template doesn´t consider the duration of those fixtures, only the GPC (gallons per cycle) volume. The Template doesn´t allows two different durations in the same fixture and, when selecting the “metering” type of Public Faucet, the template only uses the GPC field so that the duration field is disregarded. How do I consider this change on template calculations?
2 - The latest version of LEED NC & CS v3.0 Addenda, establishes in note with ID number 100000754 that “kitchen sinks” category encompasses all sinks in public or private buildings that are used with patterns and purposes similar to a sink in a residential sink, including break room sinks. However the default calculation of WEp1, estipulate for kitchen sinks one daily 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., with 15 seconds duration, not being a representative consumption for break rooms in office towers. Those buildings have commonly a small break room for large office areas, moreover, the great part of occupants have lunch outside the building. Usually in C&S projects it is not known the right percentage of occupants which use kitchen sinks in break rooms. In order to have a realistic scenario of water consumption, what is the daily use number that should be considered for kitchen sink use?
3 - The latest version of LEED NC & CS v3.0 Addenda, establishes in note with ID number 100000754 that "kitchen sinks" category encompasses all sinks in public or private buildings that are used with patterns and purposes similar to a sink in a residential kitchen. However professional grade / commercial faucets such as those used in a commercial kitchen would not be included. Based on this consideration, we have some questions:
• In a building with large refectory for the occupants, if there are kitchen sinks in the professional kitchen, how do I consider the water consumption for this type of fixture, since its water consumption in such project is representative?
• Considering that pre-rinse sprays are used only in professional / commercial grade kitchens, in which cases should pre-rinse sprays be considered in the calculations?
Could somebody help me?
Bests regards.
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 InterpretationLEED Interpretations are official answers to technical inquiries about implementing LEED on a project. They help people understand how their projects can meet LEED requirements and provide clarity on existing options. LEED Interpretations are to be used by any project certifying under an applicable rating system. All project teams are required to adhere to all LEED Interpretations posted before their registration date. This also applies to other addenda. Adherence to rulings posted after a project registers is optional, but strongly encouraged. LEED Interpretations are published in a searchable database at usgbc.org. 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
No Fixtures Installed in Core & Shell Scope
From what I have read on this website, my understanding is that if we are not installing any plumbing fixtures as part of the Core & Shell work, then we must make the water reduction a requirement in the Tenant Leases. I do not understand this. If this were a LEED-NC project, I would understand the requirement to write it into the Leases, but this is a LEED-CS project. Since we are not installing any plumbing fixtures as part of the Core & Shell work, shouldn't we achieve this Prerequisite by default? Zero plumbing fixtures = 100% reduction. No? Can someone please explain this?
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.
Faucet Aerators use
Can someone confirm me that the use of faucet aerators is an allowed way to achieve WEp1 WE c3 for Leed CS v3 ? It's impossible to find a faucet with a so low flow rate in italy. If someone knows some Italian brand of high performance faucets please let me know.
Alessio, faucet aerators are definitely allowed for WEp1/c3.
BLOW-OUT FIXTURE FOR CS v2.0
First of all, I’m sorry for posting a question of the v2.0 Guide in the 2009 page, but there is no space for CS v2.0 projects anymore.
I am working on a Core&Shell v2.0 project where an efficient blow-out fixture (short flush = .8 (gpf) and full flush feeds water under pressure, continuously) has been installed, but the Core&Shell v2.0 Guide does not provide a blow-out fixture baseline while the 2009 Guide does. What should I do in this case? Could I use the 2009 baseline case (3.5gpf) to submit a project that is v2.0? or I cannot attempt to this credit because the v2.0 guide does not have a baseline case for blow-out fixtures?
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 InterpretationLEED Interpretations are official answers to technical inquiries about implementing LEED on a project. They help people understand how their projects can meet LEED requirements and provide clarity on existing options. LEED Interpretations are to be used by any project certifying under an applicable rating system. All project teams are required to adhere to all LEED Interpretations posted before their registration date. This also applies to other addenda. Adherence to rulings posted after a project registers is optional, but strongly encouraged. LEED Interpretations are published in a searchable database at usgbc.org. to the GBCI in order to get clear direction on how to document the project’s water use reduction with this specific fixture.
Aquifer use
Our project has underground water with potable quality. Will the use of this water be considered an option for reducing the 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 that is supplied by municipal sources?
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..
Transient fixture uses
Hi There,
I've got two projects, one is a shopping mall and the other a health clinic, but I can't figure out the uses for the respective transients. I've addopted for the shopping transients the retail customer default use (in table 2 - CSv3 Guide), is that right? And for the Health Clinic, how can I sort that uses?
Was I Clear? Thank you all!
Fabiano, you may just have to make it up! Does the client have any idea what the transient population will be?
WE Prerequisite qualification for a minimal CS project
Our client is building a Retail center for a large grocer with small satellite retail spaces. The balance of the building is simply a parking garage with an enclosed and tempered elevator lobby. The owner is considering installing the Shower and Changing Rooms for the tenants but no other plumbing will be provided elsewhere. If we don't build out the Shower Room, how else can we meet the 20% reduction to qualify as a LEED project? There is also no intention to require the tenants to reduce water usage as part of their lease.
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.
WEp1 - Handheld bidet faucets
Every toilet stall in the project includes a handheld bidet faucet (or spray) and a lavatory. Are these calculated as lavatory faucets or ignored in the water use calculation?
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.
Driver's Toilets in a Core & Shell Building
Hi,
We are working on a luxurious Core & Shell Residential Building. The future tenants will decide on the water fixtures for their own flats/apartments. However, there will also be toilets in basement levels that can only be used by the drivers of future tenants. The fixtures of these toilets will be specified by the current design team.
Should we consider these toilets as Private or Public ? The drivers will need a key to access these toilets, and we therefore think they should be considered as private.
I would appreciate your feedback on the above,
George, due to the controlled access they sound "private" to me.
thanks Tristan !
WEp1 - LEED Online sample form
The LEED Online sample form for water use reduction shows 21% reduction of water use in all fixtures. However, at the end of the form it indicates "N".
What is the reason for that?
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".
WEp1 - Local Code
How to earn Water Use Reduction Points, when the local code requires e.g. minimum flow for Commercial lavatory faucets=1.6 gpm and over the baseline for other fixtures, too.
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.
Design Case vs Baseline Case
I´m working on the template and I want to know if in the baseline case I input the conventional public lavatory faucet of 0.5 gpm can I input for the desing case 0.25 gpc of the metering faucets that will be installed? The way I see it is that we´re saving half of the water by installing metering faucets instead of the conventional ones, but when I select metering from the template it automatically brings in the baseline a value of 0.25 gpc, can I compare conventional vs metering faucets when calculating the % reduction?
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 faucetsAutocontrol faucets have automatic fixture sensors or metering controls.. Link here: http://www.usgbc.org/ShowFile.aspx?DocumentID=6493
Have you checked this out?
documentation of adjustable flowrates
Has anyone experience with the documentation of adjustable flowrates?
Some fixtures like faucets and showerheads can be adjusted to a lower flowrate, however the spec sheet only shows a range.
Will the USBC accept the minimum flowrate if I claim that the fixture has been adjusted to it?
Thanks a lot in advance
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.
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