NC-2009 WEp1: Water Use Reduction—20% Reduction

  • NC CS Schools CI WEp1 Action Steps Diagram
  • 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.

    Clearly defining Fixture Usage Groups is an important step in achieving this credit. In buildings with toilet facilities that are not accessible to visitors, it is reasonable to exclude visitor numbers from the Fixture Usage Groups. The occupancy values entered in the PI forms should inform, but not necessarily parallel the numbers used for this credit. 

    Follow these key steps

    1. 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.
    2. Determine the Baseline Case Water Use Budget for Indoor Water Use.
    3. Choose fixtures and water reduction or reuse strategies. 
    4. Estimate the project’s water usage by creating a Design Case Water Use Budget. 
    5. Use the LEED Online credit form to compare the baseline and design case water budgets to determine the water reduction percentage for the project. 
    6. Complete the LEED Online credit form and upload water fixture cut sheets.

    Sample water use reduction chart for a commercial building.

    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.

  • 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.

  • 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

Pre-Design

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  • Check local codes and incentives for water-saving opportunities and restrictions. Rebates are common, as are plumbing codes restricting some water-savings technologies such as waterless urinals, graywater reuse, on-site wastewater treatment and reuse, rainwater harvesting, composting toilets, and other strategies.


  • Graywater and rainwater collection systems may offer the potential for non-potable water to be used in interior applications, helping to achieve this prerequisite, and the additional water-reduction credit.


  • Perform a Water Balance Study for the entire project to make informed decisions about where to focus water savings efforts. Look for all water sources on the site, such as stormwater, graywater, and onsite water, and note opportunities for using that water for interior water use and or irrigation. 


  • Calculating outdoor water use is not required for this prerequisite . However, understanding how indoor water use compares to outdoor water use can help you gauge where to focus reduction efforts for the greatest benefit. Some water saving strategies address both indoor and outdoor water needs holistically. For example, graywater from interior sink fixtures can be collected for landscape irrigation.


  • Graywater used for landscaping cannot be calculated for this prerequisite, but can be counted in WEc1: Water Efficient Landscaping.


  • Are composting toilets an option? While not common, composting toilets can go a long way toward achieving this prerequisite. They affect programming and layout, so consider them early.


  • Consider setting water-reduction goals higher than the 20% reduction required by this prerequisite. Many projects are able to achieve 30%–40% savings with little or no impact on cost. First-time costs for water savings above 20% can be minimal since project teams will already be integrating water-saving techniques for this prerequisite.

Schematic Design

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  • Estimate the project’s baseline water needs and determine the baseline water use budget for indoor water use. This helps determine where the most effective water-saving technologies can be applied.


  • Establish goals for water use reduction and include these goals in the Owner’s Project Requirements (OPR) for EAp1: Fundamental Commissioning. Consider aiming higher than a 20% reduction. Many of the same strategies used for this prerequisite will also apply to WEc2: Innovative Wastewater Technologies and WEc3: Water Use Reduction.


  • Determine the numbers and types of occupants in the building. The water use calculation is based on occupant use and the number of full-time equivalent (FTE) occupants, including employees and visitors, not the number of water fixtures installed.



  • Determine user groups for the various fixtures as not all occupants may be using all the fixtures; for example, employee restrooms and customer toilets in a retail store will have different use patterns.


  • The baseline for commercial lavatory faucets has been changed in LEED 2009 to 0.5 gpm.  The previous baseline for commercial lavatory faucets was 2.5 gpm. Take note of this more stringent requirement compared with earlier versions of LEED.


  • This prerequisite only includes core water uses—bathroom lavatories, water closets, urinals, showers, kitchen faucets and pre-rinse sprays. Janitors’ sinks, pot fillers, and tub faucets can be left out as they are used to fill containers with a fixed water volume regardless of the flow rate. "Kitchen sinks" includes all sinks in public or private buildings that are used with patterns and purposes similar to a sink in a residential kitchen. Break room sinks would be included; commercial kitchen sinks are not included. Lavatory faucets refer to hand-washing sinks, regardless of location, but lab or healthcare sinks with regulated flow rates are excluded. Pot-filling sinks can be excluded.


  • Appliance and process water uses such as clothes washers, dishwashers, cooling tower make-up, and others, do not need to be included in the LEED water reduction calculations.  However, teams do have the option of earning an additional point for reduced appliance and process water as part of an exemplary performance point, building on the 30%–40% water-use reduction for WEc3: Water Use Reduction.


  • Well water and pond water are not considered “reused” water for the purposes of this credit and must count as potable water—so you don’t get credit for substituting them for conventional water sources. Water types that do count as reused are: graywater (lavatory, sink and shower water), rainwater, treated wastewater, air-conditioner condensate, reverse-osmosis reject, and sump-pump water.

Design Development

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  • Select water-efficient fixtures and strategies. Gather information on applicable fixtures including manufacturer, model number, and flush or flow rates.


  • For residential projects, showers typically use more water than any other fixtures due to the duration of use. For commercial projects, toilets and urinals typically use more water. Water-saving strategies should target the most consumptive fixtures to achieve greatest water reductions.


  • Compare the baseline and design case water use budgets to determine the water reduction percentage goals for the project. The LEED Online credit form has a built-in calculator to facilitate this calculation. Repeat this process until final selection of water fixtures and strategies have been made and the project’s water reduction goals are satisfied. 


  • Size graywater and rainwater systems to match non-potable water demand, for needs such as toilet flushing, cooling tower makeup, and irrigation.


  • Untreated rainwater, graywater, and blackwater may corrode plumbing systems, or lead to biological growth. Teams should plan for water treatment, filtration, or using corrosion-resistant materials. The use of seawater for toilet flushing, although very uncommon, can cause similar problems.


  • Plumbing piping must be doubled for interior water fixtures when graywater or rainwater is reused in addition to potable water. This is likely to add upfront costs, while potentially reducing water and sewer charges.


  • Sensors on toilets and faucets are perceived as saving water. However, several studies have shown that while they may offer some hygiene or other operational benefits, they increase water use substantially, due to “phantom flushes” and faucets running longer than needed. If you do choose lavatory sensors, look for models with adjustable flow durations. Although the LEED calculation estimates a standard 30-second use, setting the flow duration to a shorter time interval can help save water. In other words, adjusting the LEED design case calculation to a more accurate (and shorter) flow duration can help you meet the 20% reduction.


  • Aerators are very cost-effective, costing only a few dollars per fixture. Installing an aerator allows you to chose the sink fixtures that are desired and not have to worry if they are low–flow—simply purchase compatible aerators in addition to the fixtures. You can also easily retrofit existing faucets with low-flow aerators.


  • Many commercial toilets can be retrofitted with dual-flush flushometers, costing less than installing new dual-flush toilets. Check with manufacturers for retrofitting compatibility.

Construction Documents

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  • Integrate efficient water fixture specifications into construction and design development documentation.


  • Specify signage for water strategies that may require special instructions for use. This may include occupant signage for operating dual-flush toilets, indicating non-potable water, and operational signage for distinguishing pipes carrying reused water.


  • If reusing graywater or rainwater, ensure that key system components such as treatment and cisterns are not removed during value engineering.


  • Fill out the LEED Online credit form and upload water fixture cut sheets to LEED Online.


  • You must use an Alternative Compliance Path to document savings from a non-potable source in LEED Online. Adjust the design case total water use volume to account for the annual amount of non‐potable water. Then use the adjusted design case total water use to recalculate the percent reduction of water use for all fixtures. Additional documentation or calculations may include but are not limited to plumbing drawings, calculations and system capacity to support quantities provided, and any analysis to confirm the availability of the non‐potable water source.

Construction

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  • The contractor ensures that the correct fixtures have been purchased and any applicable water reuse systems or specified metering systems have been installed. 


  • Make sure supply pipes carrying non-potable water are clearly labeled and color-coded to avoid inadvertent cross-connection with potable water lines.

Operations & Maintenance

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  • Apply for water-reduction incentives and rebates through municipal water authorities.


  • Provide building managers with manuals for all irrigation systems and controls, fixtures and fittings, water-reuse technologies, on-site water treatment systems, and unconventional products.


  • Consider installing permanent water metering for ongoing monitoring of the project’s water use. A sub-metering system can help operations staff detect problems early and facilitate future LEED-EBOM certification.


  • Train cleaning and operations staff to maintain atypical fixtures such as waterless urinals, water sensors and other fixtures.

  • USGBC

    Excerpted from LEED 2009 for New Construction and Major Renovations

    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. [Europe ACP: Water Use Baseline]

    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 lpf
    Commercial 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 faucets




    8.5 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 faucets




    Showerheads 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 lpf
    Residential 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 faucets




    Residential 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

    Alternative Compliance Paths (ACPs)

    Europe ACP: Water Use Baseline

    Projects in Europe may use the values defined by European Standards.

    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.

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.)

Product Cut Sheets

Carefully research products and examine cut sheets to find fixtures and fittings meeting the credit requirements, as shown in these examples.

LEED Online Forms: NC-2009 WE

The following links take you to the public, informational versions of the dynamic LEED Online forms for each NC-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:

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."

Design Submittal

PencilDocumentation for this credit can be part of a Design Phase submittal.

667 Comments

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Pia Öhrling Piacon
Jun 15 2015
LEEDuser Member
44 Thumbs Up

Dual Showerheads

Project Location: Sweden

We have a hotel where the showers have two showerheads. One showerhead placed overhead and one han-held showerhead. They have different flow-data.
Both showerheads will be used, but we do not know how much each of the showerheads will be used.
Which flow data shall we use? The highest flow or the average flow, or?

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Michelle Robinson Re:Vision Architecture Jun 15 2015 LEEDuser Member 971 Thumbs Up

I believe you need to use the worst-case scenario (the highest flow rate). Along those lines, if they can be used simultaneously, I believe you'll need to add the two rates together...

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Ian McCall Environmental Engineer Le Sommer Environnement
May 13 2015
LEEDuser Member
779 Thumbs Up

Coffee Room Fixture Flow Rate?

Project Location: France

Hello,
From what I can tell coffee room water fixtures (used for washing coffee cups and hands) in open office spaces are to be included in the credit.
What is the baseline flow rate for this fixture ? Is it 2.2 gpm (8.5 lpm) or 0.5 gpm (2.0 lpm)?
Regards,
Ian

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Charles Nepps May 13 2015 LEEDuser Member 533 Thumbs Up

You would use "Kitchen Sink" as the fixture family in Table WEp1-4, which has a baseline of 2.2 gpm

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CATALINA CABALLERO SUSTAINABILITY COORDINATOR JALRW Eng. Group Inc.
Apr 16 2015
LEEDuser Member
3682 Thumbs Up

Patient rooms showers/lavs/water closet at Rehab Center?

I was wondering if fixtures at patient rooms can be classified as residential or private? given that it is a public institution, I'm guessing it would gear more towards "private" but this would apply only to lavatories, what about water closets and showers?

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Michelle Robinson Re:Vision Architecture Apr 16 2015 LEEDuser Member 971 Thumbs Up

There was an addenda last fall (Oct. 2014) that hopefully clarifies it for you - Addenda ID#100001966 :
http://www.usgbc.org/leed-interpretations?keys=ID%23100001966
"For healthcare projects, ... Lavatories in hospital inpatient bathrooms and inpatient rooms are considered private. The inpatient lavatory and water closet should use the default residential usage assumptions (of five times per day per residential occupant), unless specific project conditions warrant an alternative. Lavatories in hospital inpatient rooms (outside the bathrooms) are considered private if used by patients and/or staff similarly to a residential lavatory, or can be exempt if they are used by staff primarily for medical or clinical use..."

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Susan Walter Sr Project Architect, Wilmot/Sanz Apr 16 2015 LEEDuser Expert 17534 Thumbs Up

The LI Michelle correctly brings up is based on the assumption that these patient rooms are private sleep rooms. Rehab facilities often have semi-private sleep rooms. Since we don't know your floor plan, I thought this was pertinent to this conversation.

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CATALINA CABALLERO SUSTAINABILITY COORDINATOR, JALRW Eng. Group Inc. Apr 17 2015 LEEDuser Member 3682 Thumbs Up

Thanks, it is very helpful information. We have 2 rooms (with 2 patients each) that are served by one joined bathroom (Water closet, lavatory and shower). 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 is very explicit, however they don't mention showerheads. Since these are a big water consumers could you clarify? Thanks

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Susan Walter Sr Project Architect, Wilmot/Sanz Apr 17 2015 LEEDuser Expert 17534 Thumbs Up

i would say that the shared bathroom is public and that the shower head counts in the calculation. It is a regulated fixture.

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Michelle Robinson Re:Vision Architecture Apr 17 2015 LEEDuser Member 971 Thumbs Up

I don't know, but my gut would say the shared bathrooms are still "used by patients ... similarly to a residential" bathroom and should therefore be calculated based on residential usage. And I would assume the showers would be used the same as the toilets and bathroom sink -- i.e. residential usage. But that's just what my gut says. I think it really depends on how it's being used. Is this similar to the bathroom that the Brandy Bunch had -- you know one bathroom in between two bedrooms like in a house? Are the patients "living" in these bedrooms that the bathroom is connected to? Do the usage patterns listed in the LEED Ref. Guide seem like they are appropriate or inappropriate for how they'll be used?

That said, if they are considered public, the water calculations will allow for a lot less water (particularly on the lav), which would be your worst case calculations, so assuming that for the calculations would be "safer."

Personally, with my limited knowledge of how they're being used, I'd probably try to make the argument that they're residential (assuming the people using them are "living" there for multiple nights in a row) and cross my fingers...

Good luck!

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Michelle Robinson Re:Vision Architecture Apr 17 2015 LEEDuser Member 971 Thumbs Up

[Sorry, Internet Explorer gave me problems and apparently posted twice even though it looked like it didn't post at all. Hopefully someone "official" can delete this comment?!?!?!]

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Robin Dukelow, LEED AP BD+C Sustainability Consultant; Project Manager Henderson Engineers, Inc.; Sustainable Design Consulting, LLC
Mar 31 2015
LEEDuser Member
47 Thumbs Up

Mechanic Area Washfountatin

Project Location: United States

We have a NC-2009 project were there is an automotive service area that has a washfountain for use by the mechanics only. They also have a locker room area with toilets, urinals, lav's, and showers. Should the washfountain 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.' because it is used for operational processes and not covered by EPAct 1992 or should it be included in the WEP1 calculations? Thank you!

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Susan Walter Sr Project Architect, Wilmot/Sanz Apr 16 2015 LEEDuser Expert 17534 Thumbs Up

You may want to review the conversations about commercial kitchens on this board. I believe the practice there has been to have the hand wash sinks align with LEED WEp1.

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Deepika Parmar Ms
Mar 22 2015
Guest
21 Thumbs Up

Occupancy Proof

Project Location: Qatar

What is the documented proof required to be submitted to USGBC confirming on the Occupancy considered for our project. Will a letter from the client confirming on 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., while assumptions on the transients suffice, or do we need to provide furniture layouts showing the seating arrangements? Also, in cases where furniture layouts are unavailable how can this be addressed?

Thankyou

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Charles Nepps Mar 22 2015 LEEDuser Member 533 Thumbs Up

Appendix 1 of the Reference guide says: "Projects that know the tenant occupancy must use the actual numbers, as long as the gross square foot per employee is not greater than that in the default occupancy count table. If code requirements required gross square foot per occupant is less than
those in the table, this is also acceptable." So as long as your occupancy numbers meet these requirements, no other documentation should be needed. As far as transients, include a narrative explaining your assumptions, and you should be ok.

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Deepika Parmar Ms Mar 30 2015 Guest 21 Thumbs Up

Thanks Charles

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Marni Punt Associate Aurecon
Mar 18 2015
LEEDuser Member
25 Thumbs Up

Car wash bay

Project Location: South Africa

Hi, I am working on an office building and the team is considering to include a car wash bayA bay is a component of a standard, rectilinear building design. It is the open area defined by a building element such as columns or a window. Typically, there are multiple identical bays in succession.. Would I be able to classify this 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. and exclude it from the WEp1 calculation?

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Michelle Robinson Re:Vision Architecture Mar 18 2015 LEEDuser Member 971 Thumbs Up

Correct. Since car washes are not regulated by the Energy Policy Act of 1992, it is excluded from the WEp1/WEc3 Indoor Water Use Reduction calculations.

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Marni Punt Associate, Aurecon Mar 19 2015 LEEDuser Member 25 Thumbs Up

Michelle, thank you for the quick response!

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Michelle Rosenberger Partner ArchEcology, LLC
Mar 04 2015
LEEDuser Member
6712 Thumbs Up

Metered Faucets w/less than 12 Sec Duration

I have received my second metered lav faucet submittal with less than 12 sec from factory duration. This American Standard faucet is a 0.35 gpm faucet that is factory set for 7.5 seconds for a 0.044 gpc. I am aware that LEED does not permit a duration less than 12 secs in the metered faucet calcs because they don't believe that hands can be washed effectively in less than 12 seconds.

Obviously I can do the calc with 12 secs despite the duration noted, but my concern is that the faucet itself may be rejected for the shorter preset duration. Am I supposed to reject this faucet or have it manually reset to a longer duration because it's too much water reduction?

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Charles Nepps Mar 04 2015 LEEDuser Member 533 Thumbs Up

That's an interesting question. Yes, LEED requires you do the calcs and determine the gpc based on 12 seconds, but obviously with a factory pre-set of 7.5, if it's activated twice, for a thorough hand washing, that would be 15 seconds. The reality is that it will average out over time: some 7.5 sec, some 15 sec, some 0 seconds. Just enter the value based on a 12 second cycle and you'll be fine.

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Michelle Rosenberger Partner, ArchEcology, LLC Mar 04 2015 LEEDuser Member 6712 Thumbs Up

Hi Charles,
I agree that is probably what the answer will be, but I find the issue interesting because it is a conflict of imperatives - water reduction vs. "effective handwashing duration". When this duration cap was originally set, it appeared to be within a context of people trying to game the calcs for points. And that made sense, despite the somewhat arbitrary seeming number 12.

But now the industry has responded with even lower fixture durations and this approach disincentivizes water reduction below a certain level. While I don't disagree with your comment about activating it twice and averaging, that could also be said of all the low flush fixtures, particularly dual flush, and we are not obliged to overstate their use.

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Charles Nepps Mar 05 2015 LEEDuser Member 533 Thumbs Up

Michelle, I agree; whether or not LEED guidelines accurately predict individual behavior is difficult to say. I would assume as more actual water usage data is collected from certified projects and compared to the predicted performance, the guidelines will be refined. My gut feeling is the current limits probably overstate water usage in most public/office restrooms.

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Jean Marais b.i.g. Bechtold DesignBuilder Expert Mar 05 2015 LEEDuser Member 9897 Thumbs Up

The installation time limit doesn't matter for LEED. In LEED theory, if the setting is 5 seconds, the user will switch the faucet on enough times to reach the 12 second limit.

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Michelle Rosenberger Partner, ArchEcology, LLC Mar 09 2015 LEEDuser Member 6712 Thumbs Up

FYI, answer as expected is "Projects should use a 12 second design case duration for LEED calc purposes, which allows projects to earn some savings for autocontrol faucetsAutocontrol faucets have automatic fixture sensors or metering controls., but not for the durations where users are likely to reactivate in order to fully wash their hands. As such projects may select faucets with cycles of any duration, and may set those faucets as they see fit".

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Charles Nepps Mar 09 2015 LEEDuser Member 533 Thumbs Up

Interesting. Does the faucet have a proximity sensor, or is it simply on for 7.5 seconds, then off`? I have had success with faucets pre-set to turn off after 6 seconds, once hands are removed from the "active range".

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LEED Consultant Green Building and Alternative Energy
Mar 02 2015
LEEDuser Member
1981 Thumbs Up

Wastewater treatment plant offsite

Hello all,

We are working on an industrial facility project were the wastewater treatment plant is offsite the project. The project is located in an industrial complex with the necessary infrastructure for treating wastewater.

The water will be send to the treatment plant (we have a signed contract between the owner and the industrial complex administration), and then the local government will supply the treated water, since the government runs the plant for the treated water supply (we also have the signed contract between the owner and the local government).

Is this a feasible way for obtaining the pre-requisite WEp1 and the credit WEc3? because, reading the document WEp1 Additional Guidance, the document indicates:

"Sources of 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. that do not apply to the Water Use Reduction prerequisite and credit include: municipally treated wastewater...."

In this case the wastewater from the project will be send to the treatment plant in order to obtain treated water supply by using the existing infrastructure in the area.

Thank you in advance,

Regards!

Isabel.

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Kathryn West LEED AP BD+C, O+M, Green Globes Professional, Guiding Principles Compliance Professional Energy Ace
Mar 02 2015
Guest
4987 Thumbs Up

Transients vs. Retail?

is there a definition for transients versus retail?

We have a dining hall and aren't sure how to classify the students who enter the building for meals.

The definition for Transient users in the reference guide isn't helpful...

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Charles Nepps Mar 02 2015 LEEDuser Member 533 Thumbs Up

Students using a dining hall would be considered "transients". You just need to estimate the number of total of "student hours" the hall is used and then divide by 8 hours per day to determine 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.. So for example, 100 students spending an average of 2 hrs/day in the hall would come out to 25 FTE's

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Kathryn West LEED AP BD+C, O+M, Green Globes Professional, Guiding Principles Compliance Professional, Energy Ace Mar 10 2015 Guest 4987 Thumbs Up

that doesn't make sense to me... why would they have different categories in the form if you just convert them to 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. at the end of the day....

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Charles Nepps Mar 10 2015 LEEDuser Member 533 Thumbs Up

It makes a difference as to how the water usage is calculated.
Per the Reference Guide (p171) "Most buildings with students, visitors, and retail customers will also have 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. occupants. Half of all students and visitors are assumed to use a flush fixture and a lavatory faucet in the building and are not expected to use a shower or kitchen sink. A fifth of retail customers are assumed to use a flush and a flow fixture in the building and no shower or kitchen sink."

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Susan Walter Sr Project Architect, Wilmot/Sanz Mar 10 2015 LEEDuser Expert 17534 Thumbs Up

Because there is more than one way to view something? Personally, I would not have used Charles' method although I do see it as valid. The transient population is variable and their behavior changes throughout the day. The form is allowing you to customize. For example, your students may not make use of the facilities at dinner because they've been to their dorms before hand but they may use them during lunch. If your lunch population is less than your dinner population, then you can adjust the water use in the form instead of making sweeping assumptions that may not be applicable to the individual project.

For the record, I would not have done things the way Charles does not because I feel he is wrong but because our projects have transients that have more predictable behavior which allows us to model more accurately. His way is completely valid.

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Kathryn West LEED AP BD+C, O+M, Green Globes Professional, Guiding Principles Compliance Professional, Energy Ace Mar 10 2015 Guest 4987 Thumbs Up

thanks guys!!! I am going to try to get more info from the owner to see how long these students are expected to dine in the building per day to make the usage as accurate as possible. I'm hoping they are more like retail than transients because our flow fixtures in a residential part of the building are about ~10% more efficient than our dining hall fixtures. I was confused by converting them to 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. in the form even though the math makes sense. I'd love to get this form approved on the first round of review.

It's also a little hard for us to estimate how many kitchen sink uses will occur in the dorms since the kitchens are very few and far between.

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Ayda Sahaf Building Analyst IG
Mar 01 2015
Guest

WEP1 for A project in Middle East

The project I am working on is an office building located in middle east. the Washroom water closets all has water jets or a bun gun fixture for washing purpose instead of using toilet paper. Shall these fixtures be included in WEp1 or WEc3 credits? and if yes under which family group should they be ?

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Michelle Robinson Re:Vision Architecture Mar 05 2015 LEEDuser Member 971 Thumbs Up

Since these are not regulated by Energy Policy Act they are exempt and are NOT included in the WEp1/WEc3 calcs.

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Todd Bundren Director of Sustainabilty - Architectural Project Manager Lawrence Group
Feb 24 2015
LEEDuser Member
1450 Thumbs Up

WEp1 - PIf3 link - new LEED on line

Project Location: United States

My project was upgraded to the new version of LEED online around the beginning of the year so I am getting used to the new set up (so far it is very nice). Question: My plumbing engineer has said in the past his WEp1 form has been linked to 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. information in PIf3. Is this accurate? I thought the FTE count in PIf3 wasn't specifically "linked" to the WEp1 credit template as the groups could be slightly different. This is a bit complicated as we are pursuing a multiple building certification and are dealing with University dorms with a dining hall so the FTEs are complicated to say the least. Am I correct that there isn't a "link" missing between the PIf3 and the WEp1 template? I really appreciate the help!

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Kathryn West LEED AP BD+C, O+M, Green Globes Professional, Guiding Principles Compliance Professional, Energy Ace Feb 24 2015 Guest 4987 Thumbs Up

your overall numbers in WEp1 should add up to equal the numnbers in PIf3. So if you have 100 dining hall 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 300 visitors and 100 residents that should be the same between WEp1 and PIf3 or your reviewers will point out the discrepancy and deny the credit. You can split them up however the fixture groups work out. So you might have 50 dining hall FTE using one set of fixtures and 50 dining hall FTE using another but if you had a split that didn't add up to 100 FTE you'd have a problem. The WEp1 form lists the data you included in PIf3 but then you set your fixture groups on your own manually. That data at the top of Wep1 is autopopulated from PIf3.

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Laura Charlier LEED Services Director Group14 Engineering
Feb 20 2015
LEEDuser Member
455 Thumbs Up

Exam room sinks

Project Location: United States

Do sinks in exam rooms need to be included in the calculations? They are primarily used for handwashing. If so, are they entered as 'sinks' or 'lavatories' as the baseline?

Thanks.

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Susan Walter Sr Project Architect, Wilmot/Sanz Feb 20 2015 LEEDuser Expert 17534 Thumbs Up

In LEED HC, clinical sinks are specifically exempt from the calculation and exam rooms are clinical use fixtures. There are a lot of other healthcare regulations and research about the flow rates on these sinks. If your owner is being fairly pushy about it, you need to accept what they are telling you.

My thoughts are that NC will follow the HC guide on the exempting these sinks and I'm pretty certain it would. There is likely 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. or LEED Addenda for NC but I don't have it at my fingertips at the moment. Do write in your narrative that you've exempted the sinks due to the clinical nature and the demands of the clinical environment.

Patient bathroom sinks for inpatient rooms are still included but are private.

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Carlie Bullock-Jones, LEED Fellow Principal, Ecoworks Studio Feb 20 2015 LEEDuser Expert 2883 Thumbs Up

WEp1 Water Use Reduction addenda, dated 2/2/2011, states that faucets whose usage patterns and flow rates are regulated for medical or industrial purposes are exempt from this calculation. Exam sink fixtures are not covered by the EPAct 1992 standard, Uniform Plumbing Code, or International Plumbing Code, as required by WEp1 requirements, and can skew water use consumption due to not having a standardized code that defines typical daily uses.

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Michelle Robinson Re:Vision Architecture Feb 20 2015 LEEDuser Member 971 Thumbs Up

There was also an addenda more recently (Oct. 2014) that clarifies it in more detail - Addenda ID#100001966 :

http://www.usgbc.org/leed-interpretations?keys=ID%23100001966

"For healthcare projects, fixtures used for clinical use related to medical procedures, such as surgical scrub sinks and exam rooms sinks, in hospitals and medical office buildings are excluded from the water use calculations. Medication room sinks, utility room sinks, and other exam / procedure / observation room sinks for clinical use are also excluded. Should exam / procedure / observation room sinks be used primarily for hand-washing, they may be included in the water use calculations at the project team’s discretion under the public lavatory category. If included, project teams should provide a narrative explaining the usage assumptions for these sinks. Lavatories in hospital inpatient bathrooms and inpatient rooms are considered private. The inpatient lavatory and water closet should use the default residential usage assumptions (of five times per day per residential occupant), unless specific project conditions warrant an alternative. Lavatories in hospital inpatient rooms (outside the bathrooms) are considered private if used by patients and/or staff similarly to a residential lavatory, or can be exempt if they are used by staff primarily for medical or clinical use.
Nutrition station (pantry) sinks and hospital staff lounge sinks should be included in the water use calculations under the kitchen sink category."

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Charalampos Giannikopoulos Founder DCarbon
Feb 19 2015
LEEDuser Member
341 Thumbs Up

Existing features

For an existing building undergoing major renovation how should the existing water fixtures be handled as far as WE prerequisite is concerned? Please note that no addition to the building will take place.
Could existing fixtures, if outside the scope of renovation, be excluded from the calculations? If not, because of the lack of technical information about existing features, would measurements be accepted to the BD+C version similarly to the EBOMEBOM is an acronym for Existing Buildings: Operations & Maintenance, one of the LEED 2009 rating systems. one? Thank you in advance.

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Denise Dauplaise Architect Berners Schober
Feb 12 2015
LEEDuser Member
221 Thumbs Up

Metered Lavatory Defaults

Project Location: United States

Through a series of circumstances, we are in the appeal process to try and meet WEp1. We have determined that we can either spend a significant amount of money to install two additional urinals in ADA single-user bathrooms, or reduce the automatic flow duration on lavatory faucets below the 12 second default. We previously had listed 8 seconds for the duration (and passed), but didn't justify it in our submittal, so the prereq was denied.

Has anyone had success in justifying a duration other than the default on metered faucets? We were considering citing client request and a campus-wide average currently in place to justify it. We don't want to chance this though, as we are already in appeal. Thanks.

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Kathryn West LEED AP BD+C, O+M, Green Globes Professional, Guiding Principles Compliance Professional, Energy Ace Feb 12 2015 Guest 4987 Thumbs Up

I don't have any experience with that getting approved. I'm fairly certain they'd say 12 seconds is required for sufficient hand washing. I would not approve it and it would be very risky to submit. I believe they say this is a major no-no in the principles of LEED webinars. If you want more feedback Toto might have the best info. They had a faucet with a <12 second duration but LEED reviewers wouldn't let the duration be less than 12 seconds in the calcs. They had a good article in EDC magazine but it's no longer posted online. Best of luck.

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Carlie Bullock-Jones, LEED Fellow Principal, Ecoworks Studio Feb 12 2015 LEEDuser Expert 2883 Thumbs Up

I would caution using anything below a 12 second duration in your appeal. The USGBC Water Use Additional Guidance states that durations less than this are not permitted for LEED calculations as shorter intervals are insufficient for typical hand washing. The direction of LEED (per v4) is also moving away from giving so much credit (in v2009) to metering faucets.

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Denise Dauplaise Architect, Berners Schober Feb 12 2015 LEEDuser Member 221 Thumbs Up

Thanks for the input Kathryn and Carlie. That's exactly what we needed to know.

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Michelle Robinson Re:Vision Architecture Feb 12 2015 LEEDuser Member 971 Thumbs Up

Yeah, I've never seen less than 12 seconds approved. (And I've always seen anything less than 12 seconds be questioned and be forced to change back to 12 sec.)

You're already using 0.35 gpm aerators I assume? And dual flush toilets in those bathrooms?

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CT G
Jan 30 2015
LEEDuser Member
347 Thumbs Up

Greywater and wastewater reuse

We have seen several comments regarding the possibility (or not) to achieve both WEp1 and WEc3 through the use of on-site greywater and wastewater. We would like to confirm that, in fact, we can calculate the % of water savings by subtracting the on-site reuse of grey and wastewater for toilets and urinals, from the design annual water use as a result of the installed fixtures. A project we are working on cannot achieve a 20% reduction solely from fixtures, but is treating all of its grey and waterwater and reusing it, which means that 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. will only be used for faucets and showers, achieving a water savings of over 50%. The Additional Water Guidance (version 8) states that "projects are allowed to use on-site alternative sources of water to achieve water use reduction through an alternative compliance path". It goes on to say that "examples of on-site non-potable water sources that apply to the Water Use Reduction PREREQUISITE and credit include: greywater, captured rainwater, air conditioning condensate, etc". Because we have seen comments saying that the 20% reduction MUST be achieved through efficient fixtures, we would like to confirm that this is not the case and that, per the Additional Water Guidance, grey and wastewater reuse can in fact be used to achieve the 20% reduction.

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Charles Nepps Jan 30 2015 LEEDuser Member 533 Thumbs Up

If you are treating the grey/wastewater and then re-using it for toilet and urinal flushing, then it counts. If you use for irrigation, it doesn't. "The design case annual water use is determined by totaling the annual volume of each fixture type and subtracting any 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." (LEED Reference Guide for Green Building Design and Construction 2009 Edition)

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Courtney Royal, LEED AP BD+C Sr. Sustainability Consultant Taitem Engineering
Jan 07 2015
LEEDuser Member
1399 Thumbs Up

treat rainwater?

area you required to treat harvested rainwater when using to flush toilets? if yes, what does "treated" mean exactly, what level of treated would be required? Thanks!

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CATALINA CABALLERO SUSTAINABILITY COORDINATOR JALRW Eng. Group Inc.
Dec 24 2014
LEEDuser Member
3682 Thumbs Up

Dual flush - average flow rate and fixture uses

Looking at the Water Use Reduction - Additional Guidance in the section for Dual flush, they say: " For the female water closet usage, there is a 1:2 ratio in terms of number of full-flush to low-flush uses per day. For the male water closet usage, there is a full-flush usage per day." Does this mean that if a visitor female with 0.5 uses/day and male visitor with 0.1 uses/day according to the default fixture uses, then in the average for dual flush the default uses are broken down by the ratio like this?

Male:
(0.033 uses/day x full flush rate) + (0.066 uses/day x full flush rate) +
Female
(0.166 uses/day x full flush rate) + (0.332 uses/day x full flush rate)
divided by 0.6 total female & male uses.

Is this assumption correct?

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Carlie Bullock-Jones, LEED Fellow Principal, Ecoworks Studio Jan 05 2015 LEEDuser Expert 2883 Thumbs Up

Based on the Water Use Guidance document example you would calculate visitor dual-flushA type of water-saving toilet that gives a choice of flushes depending on the type of waste — solid or liquid. uses as:

[(0.1 use/day * 1.6 gpf) + (0.1 use/day * 1.6 gpf) + (0.4 use/day * 1.1 gpf)] / 4 uses/day = 1.27 gpf avg. flow rate (with urinals)

Hope this helps!

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Mohammed Faisal Kalaigar LEED AP(BD+C)
Dec 10 2014
Guest
26 Thumbs Up

Sensor based lavatory faucet compliance

Project Location: Saudi Arabia

Hi,
How should be the compliance (of 0.25gpc) for sensor based lavatory faucet be checked if the manufacturer mentions only “ adjustable from 1 - 20 minutes “ , the model in question is EAF-200-P-ISM(by SLOAN)

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Charles Nepps Dec 10 2014 LEEDuser Member 533 Thumbs Up

Mohammed, do you mean 1-20 seconds? The GPC should be base on 12 seconds of flow.

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Mohammed Faisal Kalaigar LEED AP(BD+C) Dec 10 2014 Guest 26 Thumbs Up

charles, you can refer the product data sheet at :
http://www.sloanvalve.com/Specifications/Optima_Lino_EAF-200.pdf

the data sheet states "Continuous Run — 2 minute default setting (adjustable from 1 - 20 minutes)"----this is all that it states with respect to sensor timing,

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Charles Nepps Dec 12 2014 LEEDuser Member 533 Thumbs Up

Mohammed, The faucet is designed only to operate when the users hands are within range of the sensor beam, and will shut off automatically after 2 minutes of continuous flow. "Water will flow until the hands are removed or until the faucet reaches its automatic timeout setting"
The 1-20 minute run time is part of the of the "iq Click Feature", which is optional. This feature allows the user to change the automatic timeout setting of the faucet to 1 - 20 minutes. The spec does states that this feature is not recommend for public restrooms.
GPC would still be calculated based on flow for 12 seconds.

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Mohammed Faisal Kalaigar LEED AP(BD+C) Dec 12 2014 Guest 26 Thumbs Up

Thanks charles

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jorge calderon earth lab
Dec 04 2014
Guest
259 Thumbs Up

fixture family

If we are using an exposed WC Flush Valve, which fixture family and fixture type should we choose in table WEp1-3?

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Charles Nepps Dec 04 2014 LEEDuser Member 533 Thumbs Up

Family would still be "Water Closet", then for fixture type Select "other" and manually enter the installed flush rate.

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CATALINA CABALLERO SUSTAINABILITY COORDINATOR JALRW Eng. Group Inc.
Nov 03 2014
LEEDuser Member
3682 Thumbs Up

showers and lavatories in ammenities area

Hello,
We currently have a project of an apartment building with 5 FTEs, 8 visitors and 78 residents. It also has an amenities level with shower of 2 gpm and lavatories of 0.5 gpm, that is accessed by both the residents and the visitors. I was wondering since not all the visitors/residents will be using these fixtures at the same time what is the most appropriate uses/day that I should give to the calculation?

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Christine Harvey
Oct 17 2014
Guest
3 Thumbs Up

Pot washing sink

Project Location: United States

I saw a comment on this site that implied the water used for pot washing sinks and kitchen food prep sinks can be excluded from the calculations, can someone verify that for me? I don't see anything to back that up in the credit form or the LEED Reference Guide. Thanks!

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Michelle Rosenberger Partner, ArchEcology, LLC Oct 20 2014 LEEDuser Member 6712 Thumbs Up

Hi Christine,
Yes, excerpt from a Proven Provider presubmittal call "kitchen hand sinks that are used for food prep, wash down or cleanup (including handwashing due to these activities) should be excluded 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.. If the sink runs through a grease interceptor, it can be excluded as a process water use. If the hand sink is used primarily for hand washing or similar to breakroom kitchen sink, it can included as a kitchen sink regardless of grease interceptor."

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Shenhao Li Atkins
Oct 14 2014
Guest
334 Thumbs Up

How to calculate Squatter Toilet in we p1? and roof garden?

Project Location: China

HI, i have 2 questions to ask:
1.Now i have a hotel project in china. In this project, Several squatter toilets(with water tank) are designed and will be constructed in the future. But i can`t figure out which fixture family is more appropriate for it as the baseline(water closet or blow-out)?
Also i want to know the exactly definition of blow-out fixture.

2. Also in this project. Our client will build a roof garden. Some areas of roof garden is vegetated roof, and other area will be construct as lane, tennis court or other things. These areas are paved by wood, pebble,tiles instead of traditional roof material(paints, concrete etc.). Can we treat these parts as vegetated roof? Or equivalent SRI for these parts by material color is more acceptable? If we equivalent SRI for this parts, is it acceptable i upload a test report or cut sheets of the equivalent material? (For example, if i have a pavement constructed by green tiles, and we know the SRI of green paints is 21, can we submit the SRI of green tiles as 21?)

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Carlie Bullock-Jones, LEED Fellow Principal, Ecoworks Studio Oct 14 2014 LEEDuser Expert 2883 Thumbs Up

Hello Shenhao -

1. Check out the USGBC's Water Use Reduction Additional Guidance document found here for information on blow-out fixtures - http://www.usgbc.org/Docs/Archive/General/Docs6493.pdf

2. Be sure to post your inquiry #2 under the SSc7.2 section of LEEDuser for feedback.

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Razan Nejem Environmental Engineer, LEED AP BD+C
Sep 17 2014
LEEDuser Member
369 Thumbs Up

LEED male/female 50/50 gender ratio

Hi Everyone,

Regarding one of the FAQ's above in the birds eye view section with regards to gender ratio. I once received a comment from GBCI on a project stating the following
"The current staffing level is not an acceptable rationale for deviating from the standard usage ratio of 50/50 M/F. The calculations require a balanced, one-to-one sex ratio unless project conditions exist (such as a male dormitory) which would affect the gender ratio for the life span of the building and warrant an alternative ratio. "

hope that helps

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Perrilyn Fanfulik PE, LEED AP BD+C, WMATA Feb 27 2015 LEEDuser Member 145 Thumbs Up

We have allocated 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. per the standard ratio of 50/50 M/F. However, due to the actual users being predominately male, we have provided additional fixtures above code requirements. Is this acceptable?

Thanks.

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Michelle Robinson Re:Vision Architecture Feb 27 2015 LEEDuser Member 971 Thumbs Up

It sounds like you could argue a different ratio than the default 50/50 and take advantage of the savings if you have urinals that are lower flow (ex. 0.5 gpf vs. 1.0 gpf default = 50% savings).

Per the "Water Use Reduction Additional Guidance" (http://www.usgbc.org/resources/water-use-reduction-additional-guidance) :
"Projects specifically designed for an alternative gender ratio: ... any project that can show that flush and flow fixtures have been distributed to account for the modified ratio. Project teams must provide documentation of the code-required plumbing fixture counts per gender, so the review team can verify that the flush-fixture ratio installed in the project supports the alternative gender ratio claimed."

However, if you want to just claim the standard 50/50 ratio, I would imagine it would go through just fine...

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Perrilyn Fanfulik PE, LEED AP BD+C, WMATA Feb 27 2015 LEEDuser Member 145 Thumbs Up

Thanks so much.

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Ghaith Moufarege
Sep 05 2014
LEEDuser Member
8955 Thumbs Up

Discrepancy in graywater volume between Engineer & ELED

Dear all,

We are consulting for a big retail shopping mall. The project is aiming to achieve this prerequisite and the WEc3 by installing sanitary fixtures close to the baseline values, but complementing it with a full 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. recycling system which will collect water from all lavatories and kitchen sinks (non-greasy water of course).

The Mechanical Engineer performed calculations based on typical projects of the same size / type, and calculated around 200 cubic meter of graywater recycled per day.

We did the same calculations as per the LEED guidance , and found that the total amount of graywater is around 20 cubic meter per day (almost 10% of the Engineer's estimated value). We assumed the same flow rates of lavatories / sinks, but it seems that the Engineer has assumed more uses and also included water consumption for activities which LEED doesn't take into consideration (washing food in restaurants, water for cleaning the floor, etc).

My question is:
If I provide sufficient calculations by the Mechanical Engineer to the USGBC, would this be enough to assume the Engineer's graywater volumes in the LEED Credits? If I use the Engineer's numbers, I would be able to achieve the full 4 credits of WE Credit 3 (plus 1 ID point), in addition to the 4 credits of WE Credit 1 (Water Efficient Landscaping) as no 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. would be used for irrigation.

Anyone had a previous experience of a similar situation?
Thanks!

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Jean Marais b.i.g. Bechtold DesignBuilder Expert Sep 05 2014 LEEDuser Member 9897 Thumbs Up

I've not checked this for a while, but I must caution not to lump credit requirements together. For the prerequisite, you may only account for those elements listed and still must reach the minimum...that means regardless your greywater use, you still must have efficient taps, etc.

For greywater calcs. I think the engineer's numbers are good to use if you include them with a narritive.

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