NC-v2.2 WEc3.1-3.2: Water Use Reduction

  • NC_v2-2_WEc3_Type3_WaterUseReduction Diagram
  • It’s very doable

    Water-use reduction is a good opportunity for all projects to earn points. For this credit you will need to reduce your project’s water consumption from indoor fixtures including: water closets, urinals, lavatory faucets, showers, and kitchen sinks. Other water using appliances and irrigation are not included.

    Your baseline for determining percent reduction is based on the Energy Policy Act of 1992 fixture requirements.  You will earn one point for WEc3.1, a 20% indoor water use reduction and a total of two points for WEc3.2, a 30% reduction. You are also eligible for an Exemplary PerformanceIn LEED, certain credits have established thresholds beyond basic credit achievement. Meeting these thresholds can earn additional points through Innovation in Design (ID) or Innovation in Operations (IO) points. As a general rule of thumb, ID credits for exemplary performance are awarded for doubling the credit requirements and/or achieving the next incremental percentage threshold. However, this rule varies on a case by case basis, so check the credit requirements. point via IDc1 for a 40% reduction. The calculations for Exemplary Performance can include 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. reductions in the total, as long as the EPAct 1992 regulated fixtures first meet a 30% reduction.  

    The credits are fairly easy to achieve with careful fixture selection. You also have the option of replacing 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 non-potable sources—for example using captured rainwater or 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..

    Solutions are simple and widely available

    If you pay close attention to the flow rates of the water fixtures you select (gallons per minute for flow fixtures and gallons per flush for flush fixtures), you should be able to achieve a 30% reduction in water use by using widely available efficient fixtures—at a minimal cost premium and without compromising on comfort. 

    Some typical approaches here include low-flow faucets with sensors, low-flush or dual-flushA type of water-saving toilet that gives a choice of flushes depending on the type of waste — solid or liquid. toilets, and low-flush or waterless urinals. Use of graywater and rainwater for toilet flushing is also a fairly common way to contribute to the credit.

    Combining several of these strategies can bring your water savings within the 30%–40% range, maxing out your points for this credit. 

    Try it—you’ll like it

    When water-efficient fixtures first appeared in the 1990s, they often didn’t perform very well, creating a lot of doubts that still may be harbored by some project team members. Research and development as well as new testing protocols have really changed things since then, so make sure these doubts are put to rest. Providing hands-on experience with efficient fixtures through visiting another LEED building is a good way to do this. 

    Follow these key steps

    • Set goals for interior water-use reduction. 
    • Determine full time equivalent (FTE) occupancy and fixture usage groups. 
    • Create a baseline water 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 budget. 
    • Use the LEED Online submittal template to compare baseline and design-case water budgets to determine the water reduction percentage for the project. 
    • Complete the LEED Online submittal template.

     Consider these questions when approaching this credit

    • What occupancy patterns are expected? 
    • What are the highest-intensity water uses? How can you target these for savings?
    • Is rainwater collection feasible on your site? What are potential sources of graywater for your project? Does the municipality or local water utility supply reused water through a purple pipe? 
    • Are rebates or incentives for water-efficient fixtures available in your area?

Legend

  • Best Practices
  • Gotcha
  • Action Steps
  • Cost Tip

Pre-Design

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  • Include goals for water-use reduction in the Owner’s Project Requirements (OPR) for EAp1: Fundamental Commissioning. Reduced use of hot water with efficient fixtures can save a lot of energy. 


  • Perform a water-balance study for the entire project to inform decisions about where to focus water-saving efforts. Understand which end uses require the most water, identify all alternative water sources available onsite—such as rainwater and graywater—and note opportunities for using that water for interior water use and/or irrigation.  


  • Outdoor water use is not part of this credit. But looking at the whole system to understand how indoor water use compares to outdoor use can help you gauge where to focus reduction efforts for the greatest benefit. Some water-saving strategies can address both indoor and outdoor water needs holistically. For example, graywater collected from interior sink fixtures can be used for landscape irrigation, benefiting WEc1: Water Efficient Landscaping. However, this strategy will not contribute to a water reduction for this credit.


  • Appliance and process water uses such as clothes washers, dishwashers, cooling tower makeup, and others, are not included in the LEED water use reduction calculations for this credit.


  • You can earn an Exemplary Performance point through IDc1 for a 40% reduction. To help you meet this threshold, you can include appliance and process water in the calculations, even though that’s not allowed for the standard credit calculations. 


  • Establish preliminary goals for water-use reduction. Consider setting water-reduction goals higher than the 30% reduction required by this credit, and aim for a reduction greater than 40% or higher for exemplary performance under IDc1. You are likely to need rainwater or graywater reuse to reach this threshold. 


  • Target your efficiency efforts at fixtures that use the most water.


  • For residential projects, showers typically use more water than other fixtures due to the duration of use.


  • For commercial projects, toilets and urinals typically use more water than other fixture types. 


  • When water-efficient fixtures first appeared in the 1990s, they often didn’t perform very well, creating a lot of doubts that still may be harbored by some project team members. Research and development as well as new testing protocols have really changed things since then, so make sure these doubts are put to rest. Providing hands-on experience with efficient fixtures by visiting another LEED building is a good way to do this. Providing information on testing results of products is another good way to sway hesitations (see GreenSpec’s related products in the right-hand column for more information).


  • Are composting toilets an option? While not common, composting toilets are waterless fixtures that go a long way toward achieving this credit. However, they do affect programming and layout, so consider them early in the planning stage.


  • Consider replacing potable water use with alternative sources such as collected graywater, rainwater, municipally supplied treated wastewater, or wastewater treated onsite for reuse.


  • Well and pond water are not considered “reused” 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: 

    • Rainwater;
    • treated wastewater supplied by the municipality or water utility;
    • graywater coming from onsite lavatories, sinks, and showers;
    • treated blackwater;
    • rejected water from a reverse-osmosis treatment process;
    • sump-pump water;
    • air-conditioning and cooling tower condensate.

  • Graywater and rainwater collection systems can offer a potential non-potable water source for interior applications. However, you may find that it is easier—based on code issues and simplicity of system design—to direct reused water to an irrigation system or cooling tower. All solutions should be viewed in the context of finding the best whole-system approach for building and site water use.


  • Consider occupants when debating whether to use graywater or waterless and/or dual-flush fixtures. Cultural perceptions of these types of applications may need to be evaluated to gauge whether they will be successful in your building. It is also a good idea to have education outreach in order for building occupants to know how to use the new fixtures and to understand the importance of water reduction strategies.


  • Check local codes and restrictions. Throughout the U.S. there are widely varying laws addressing water use, and many states have very different approaches to rainwater collection and greywater/blackwater reuse. 


  • Check for local incentives through municipalities and utilities that reward or encourage water-saving strategies—as well as restrictions that may apply. Rebates are common, as are plumbing codes restricting certain water-savings technologies such as waterless urinals, graywater reuse, onsite wastewater treatment and reuse, rainwater harvesting, composting toilets, and other strategies. See Resources for more.

Schematic Design

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



  • Determine user groups for the various water fixtures, as not all occupants may be using all fixtures. For example, employee restrooms and customer toilets in a retail store have different usage patterns that would affect the water use calculations if the fixtures were different. For example: 

    • 2 male staff using a 1.6 gpf toilet 3 times per day each = 9.6 gallons a day.
    • 50 male customers using a 1.0 gpf efficient toilet  0.2 times per day each = 10 gallons a day.
    • 9.6 gallons from the staff + 10 gallons from the customers = 19.6 gallons daily.
    • If the staff got the more efficient 1.0 gpf toilet, and the customers got the less-efficient 1.6 gpf toilet, you would have employees generating 6 gallons and customers generating 16 gallons = 22 gallons daily, an increase.

  • Run preliminary water use calculations to establish the baseline water use and confirm goals for water-use reduction. This should include clearly identifying target flow and flush rates for fixtures. 


This credit only includes core water uses—bathroom sinks, toilets, urinals, showers, and kitchen faucets.


  • 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.


  • Using 0.5 gpm lavatory faucets is a cheap and easy way to help earn the majority of your water use reduction points.


  • Reductions in potable water used in flush fixtures can also contribute to the achievement of WEc2: Innovative Wastewater Technologies.


  • Healthcare projects are not permitted to include exam room sinks within their WEp1 and WEc3 calculations. These sinks would be considered "process water" and thus should not be included; in addition they are commonly regulated by different standards, and three uses per day would not capture their water use levels.

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. 


  • Use the calculator built into the LEED Online submittal template to help facilitate decision-making. Re-run comparisons between the baseline and design-case water budgets until the final selections of water fixtures and strategies have been made and the project’s water-reduction goals are satisfied.  


  • Design and 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 can 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, which is less common, can cause similar problems.


  • Piping to interior water fixtures is doubled when graywater or rainwater is reused in addition to potable water. This is likely to add upfront costs, but can potentially reduce water and sewer charges.


  • Sensors on toilets and faucets are sometimes 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 as they may interpret the flow of water as a solid object. If you do choose lavatory sensors, look for models with adjustable flow durations, and test the sensitivity of the sensor.


  • Flow restrictors and aerators can cost only a few dollars per fixture and can help add efficiency to more conventional sink fixtures. This can also be an easy inexpensive way to retrofit existing faucets; however, make sure restrictors or aerators are compatible with faucet fixtures.


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


  • Toilet-lid-sink retrofits for standard toilets are one of the most basic and easy graywater reuse tools available, costing around $100.  When toilets are flushed, potable water first flows though the sink for handwashing before filing up the toilet tank for flushing.  

Construction Documents

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  • Specify efficient water fixtures in construction documents. Be sure to include specific flow and flush rates (gpm or gpf) for each type of fixture.


  • Specify signage for water fixtures or strategies that may require special instructions for use, or educate users on water savings. This may include signage for explaining proper operation of dual-flush toilets, waterless urinals, indicating non-potable water if supplied at faucets, and distinguishing pipes carrying reused water for operations and maintenance personnel.


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


  • Apply for any water-reduction incentives and rebates available through local municipal water authorities or utilities.


  • Fill out the LEED Online submittal template and upload water fixture cut sheets to LEED Online. 

Construction

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


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

Operations & Maintenance

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  • Provide building managers with manuals and guidance for all fixtures and fittings, water-reuse technologies, onsite water treatment systems and unconventional products.


  • Consider installing permanent water metering for ongoing monitoring of the project’s water use. A submetering 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, faucet sensors and other unconventional fixtures. 

  • USGBC

    Excerpted from LEED for New Construction and Major Renovations Version 2.2

    WE Credit 3.1–3.2: Water Use Reduction

    2 Points

    Intent

    Maximize water efficiency within buildings to reduce the burden on municipal water supply and wastewater systems.

    Requirements

    Credit 3.1: 20% Reduction
    1 Point

    Employ strategies that in aggregate use 20% less water than the water use baseline calculated for the building (not including irrigation) after meeting the Energy Policy Act of 1992 fixture performance requirements. Cal- culations are based on estimated occupant usage and shall include only the following fixtures (as applicable to the building): water closets, urinals, lavatory faucets, showers and kitchen sinks.


    Credit 3.2: 30% Reduction
    1 Point

    Employ strategies that in aggregate use 30% less water than the water use baseline calculated for the building (not including irrigation) after meeting the Energy Policy Act of 1992 fixture performance requirements. Cal- culations are based on estimated occupant usage and shall include only the following fixtures (as applicable to the building): water closets, urinals, lavatory faucets, showers and kitchen sinks.

    Potential Technologies & Strategies

    Use high-efficiency fixtures, dry fixtures such as composting toiletsComposting (or Nonwater) toilet systems are dry plumbing fixtures and fittings that contain and treat human waste via microbiological processes. and waterless urinals, and occupant sensors to reduce 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. demand. Consider reuse of stormwater and greywater for non-potable applications such as toilet and urinal flushing, mechanical systems and custodial uses.

Technical Guides

Energy Policy Act of 1992 & amendments

This is a referenced standard for this credit.


2006 International Plumbing Code

This is a referenced standard for this credit.


EPA Water Sense

WaterSense label helps US consumers choose high-quality, water-efficient products.

Web Tools

WATERGY v3.0

A spreadsheet model that uses water/energy relationship assumptions to analyze the potential of water savings and associated energy savings.


EPA Water Regional & State Links

A map with regional water information.


American Standard’s Rebate Locator

Search for local rebates for water efficiency products.


Toilet Rebate

Searchable national database of toilet rebates.

Publications

How to Conserve Water and Use it Effectively

This chapter addresses the following questions: What's the problem? What practices might be used to solve it? How effective are they? What do they cost? Where have they been used successfully? Practices for system users residential, industrial/commercial, and agricultural are presented first, followed by practices for system operators.

Organizations

Alliance for Water Efficiency

An advocate for water-efficient products and programs. Provides information and assistance on water conservation efforts.


EPA Office for Water

Information and links to a range of water-related issues.


American Rainwater Catchment Systems Association

Offers web-based information exchange, workshops, and other educational opportunities.


Oasis Greywater Policy Center

Compilation 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. laws.

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 Sample Template – WEc3

This template is the flattened, public version of the dynamic template for this credit that is used within LEED-Online v2 by registered project teams. This and other public versions of LEED credit templates come from the USGBC website, and are posted on LEEDuser with USGBC's permission. You'll need to fill out the live version of this template on LEED Online to document this credit.

USGBC

Official LEED Online Forms

Design Submittal

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

73 Comments

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Suzanne Allerton Architect W2A Design Group
Aug 15 2013
Guest
899 Thumbs Up

FTE for a Community Library related to WE

Clarification regarding 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 Community Library

Our office is completing work on a community library of approximately
30,000 GSF.

The staff has been calculated to be 38 FTE – this from the total hours
of all PT and FT employees.

In order to calculate the number of daily visitors (in this case patrons)
we reviewed the visitor counts of the existing library and found an
average of the most occupied hour (the first hour after opening).

There is also a Community room in the new facility (full capacity of 126). It is not known if groups other than Library groups will use this
new room – or any data about its future patron use. Most probably
a majority of the use will be after hours use or evening use.

1. Will the reviewer be satisfied with our basis for FTE of adding the existing data of peak building patrons per the peak hour and averaging then adding to the staff FTE of 38? Or is it recommended to add a speculated average or expectation for the community room also?

We will then use the number across the credits requiring FTE.
For the WE 3.1 /3.2 Credit we plan to separate the space per the
occupancy described above, staff and patron/ public areas.

2. Also for the WE 3.1/3.2 credit we will make the case that 95% of the 38 FTE are female as there is only one male FT employee. Will this division be satisfactory?

Clarification regarding FTE for a Community Library

Our office is completing work on a community library of approximately
30,000 GSF.

The staff has been calculated to be 38 FTE – this from the total hours
of all PT and FT employees.

In order to calculate the number of daily visitors (in this case patrons)
we reviewed the visitor counts of the existing library and found an
average of the most occupied hour (the first hour after opening).

There is also a Community room in the new facility (full capacity of 126). It is not known if groups other than Library groups will use this
new room – or any data about its future patron use. Most probably
a majority of the use will be after hours use or evening use.

1. Will the reviewer be satisfied with our basis for FTE of adding the existing data of peak building patrons per the peak hour and averaging then adding to the staff FTE of 38? Or is it recommended to add a speculated average or expectation for the community room also?

We will then use the number across the credits requiring FTE.
For the WE 3.1 /3.2 Credit we plan to separate the space per the
occupancy described above, staff and patron/ public areas.

2. Also for the WE 3.1/3.2 credit we will make the case that 95% of the 38 FTE are female as there is only one male FT employee. Will this division be satisfactory?

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Kathryn West LEED AP BD+C, O+M, Green Globes Professional, Guiding Principles Compliance Professional, Energy Ace Aug 15 2013 Guest 2814 Thumbs Up

You can't assume that the staff will remain 37/38 female and 1/38 male for the life of the building. You're supposed to use the default 50/50 gender ratio unless the discrepancy is expected to exist for the life of the building. I've only seen this approved on male dormitories and fire stations.

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Sheryl Swartzle LEED administration TLC Engineering for Architecture
May 02 2013
LEEDuser Member
654 Thumbs Up

Commercial Kitchen Sinks

We are working on a Culinary Arts Bldg that has 6 commercial kitchen sinks (sinks used for dishwashing and food prep during the course of teaching students). Is this water use considered "process waterProcess water is used for industrial processes and building systems such as cooling towers, boilers, and chillers. It can also refer to water used in operational processes, such as dishwashing, clothes washing, and ice making." and excluded from WEc3 calculations in LEED NC v2.2?

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Tristan Roberts LEED AP BD+C, Editorial Director – LEEDuser, BuildingGreen, Inc. Nov 04 2013 LEEDuser Moderator

Correct. A kitchen sink is not a regulated fixture under the credit requirements.

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Sheryl Swartzle LEED administration TLC Engineering for Architecture
May 02 2013
LEEDuser Member
654 Thumbs Up

Multifamily Buidlings

We have a residential project with 72 units x 2 = 144 residents, 6 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. (onsite maintenance personnel) and a multi-purpose room (for residents and visitors to use for playing games or other gatherings) that can hold a maximum of 153 people. How do we determine the visitor count?

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Tristan Roberts LEED AP BD+C, Editorial Director – LEEDuser, BuildingGreen, Inc. Nov 04 2013 LEEDuser Moderator

Sheryl, there are no real guidelines for this. It's up to you to have some idea how the facility will be used.

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Catalina Caballero Sustainability Coordinator JALRW Eng. Group Inc.
Apr 25 2013
LEEDuser Member
2253 Thumbs Up

Rehabilitation Center Population Classification

Hello. Im having a hard time trying to classify the users of this center for water calculation purpose.Only a few would come and stay for a few days, or even not a day in some cases because its temporary stay for their detox treament.

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Susan Walter Sr Project Architect, Wilmot/Sanz Apr 26 2013 LEEDuser Expert 14152 Thumbs Up

Think less about the individual and more about the type of resident. For those spending the night, what is the average occupancy of the facility? What is the average occupancy of those not spending the night? How long are they typically at the facility? The center should have all of that information. Then set up use cases for each occupancy (staff, overnight residents, short term stay residents).

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Lawrence Lile Chief Engineer Lile Engineering LLC
Mar 05 2013
LEEDuser Member
1344 Thumbs Up

Handwashing sink in a commercial kitchen - public or private?

In a commercial kitchen, I am assuming the handwashing sink needs to be counted under the WEp1 and WE3 credits.

If that is the case, is this considered a "Private" or a "Public" lavatory. Customers cannot access it, only kitchen employees. But does this make it "Private"?

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Susan Walter Sr Project Architect, Wilmot/Sanz Mar 05 2013 LEEDuser Expert 14152 Thumbs Up

No. It is only private when it is for the use or benefit of a single person. There is likely more than one person in your commercial kitchen so the handwashing sinks are public.

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Hernando Miranda Owner, Soltierra LLC Mar 05 2013 Guest 7159 Thumbs Up

Commercial kitchens are all 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. loads. A commercial kitchen specific hand wash sink would be exempt. To properly exempt the sink it should be part of the kitchen and not part of a public or kitchen only restroom.

If a commercial kitchen dedicated restroom was part of project, you could make a case that needs to meet residential flow requirements for reason of public health and safety. Kitchen staff need to wash very well between different tasks. Going from kitchen cleaning, to food prep, to dish washing to food serving, these are not tasks that should be forced to used 0.5 gpm fixtures for a 15-second limit. And, a such a public type lav faucet should not be specified and claimed for the purposes of earn LEED credit.

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Lawrence Lile Chief Engineer, Lile Engineering LLC Mar 05 2013 LEEDuser Member 1344 Thumbs Up

Hernando's answer is the one I like the best, because it makes the kitchen sink problem dissappear! Also seems logical. Hernando, is this answer, I would assume, based on your experience with completed and reviewed LEED projects?

Would you expect the same answer for a handwashing sink in a bar - call it a process load?

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Hernando Miranda Owner, Soltierra LLC Mar 05 2013 Guest 7159 Thumbs Up

Lawence, yes it is based on all kitchen water uses being exempt as process for an approved LEED Schools project with a full-service cafeteria, with the exception of pre-rinse spray values.

For commercial (kitchen) pre-rinse spray valves the WE prerequisite is 1.6 gpm of less for all LEED projects. Schools have a 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. Credit and these need to be 1.4 gpm of less if chosen as a measure. Pre-rinse spray valves are off-calculation, meaning they only need to meet a flow rate value and annual water usage calculation is not required.

Just remember to include prerinse sprayers and you'll be okay. Don't exclude any restrooms. You'll be okay.

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Hernando Miranda Owner, Soltierra LLC Mar 05 2013 Guest 7159 Thumbs Up

...and yes, a bar sink is the same. It is not a public sink. It is a commercial washing sink. If anything such sinks should be treated similar to residential performance values, and similar to pre-rinse sprayers. That would mean 2.2 gpm with no use duration, no pressure requirement, and no annual use calculation.

If you think about it, trying to calculate use for commercial sinks is a guessing game. It is completely dependent in meals served or drinks served. These are not estimates that can be made with any sort of reliability.

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Catalina Caballero Sustainable Designer JALRW
Dec 05 2012
Guest
114 Thumbs Up

Sink at Catering Room

Would the hand sink at a catering room need to be considered in the calculation? Would it be call kitchen sink or utility sink?

Thanks

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Tristan Roberts LEED AP BD+C, Editorial Director – LEEDuser, BuildingGreen, Inc. Dec 18 2012 LEEDuser Moderator

How is the sink used? Most likely you would need to include it—only if it's a pot filler could you leave it out.

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Catalina Caballero Sustainability Coordinator, JALRW Eng. Group Inc. Dec 18 2012 LEEDuser Member 2253 Thumbs Up

Just as hand sink. They come with the food prepared already.

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Tristan Roberts LEED AP BD+C, Editorial Director – LEEDuser, BuildingGreen, Inc. Dec 18 2012 LEEDuser Moderator

Sounds like a lavatory sink, and subject to the credit requirements.

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Catalina Caballero Sustainability Coordinator, JALRW Eng. Group Inc. Feb 04 2014 LEEDuser Member 2253 Thumbs Up

what if you have a commercial kitchen sink and pre-rinse spray valve in a catering room but is only use a few times a year because is a catering room and the food comes prepared from offsite, there is no oven in the room. Would this count as lavatory?

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Kathryn West LEED AP BD+C, O+M, Green Globes Professional, Guiding Principles Compliance Professional, Energy Ace Feb 04 2014 Guest 2814 Thumbs Up

This is covered in guidance for LEEDv3. Not sure if the same applies to v2.2 Under v3 the hand sink is supposed to count unless the water goes through a grease interceptor then you can exclude it. Pre Rinse Spray valves just need to be ≤1.6 gpm. I don't think they impact your calculation but if you're more than 1.6 gpm I think you can't comply with LEED prerequisite WEp1.

A LEED addendum from 2/2/2011 states:

"the "kitchen sinks" category encompass 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. However professional grade/ commercial faucets such as those in a commercial kitchen would not be included."

Then there's another addendum from 11/1/2011 that says "hand washing sinks located in commercial kitchen areas that do not pass through a grease interceptor should be included in water use calculations under the kitchen sink category."

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Hernando Miranda Owner Soltierra LLC
Oct 21 2012
Guest
7159 Thumbs Up

Reviews Denying Duration Controls

For a recent LEED review the reviewer claimed the following:

The owner installed showers with automatic shoutoff valves. Similar to school gyms, fitness centers, and prisons.

"Please note that the flow duration for showers should be the same in the baseline and design cases as there are currently no published exceptions allowing design case savings for showers with an automatic shut off from the default baseline duration of 300 seconds."

The reviewer claims there is no published exception, but there is also no published requirement that durations must match. For LEED 2009 projects, unfortunately the LEED Online Form authors decided that water efficiency controls were a schedule measure, and not a water reducing measure. Now, they are applying the same 2009 LEED requirement backwards to v2 projects.

I find the schedule requirement odd. It does not exist in the member-approved LEED Rating system, and is counter to good green building practice. I can no longer encourage owners to install lavatory or faucet controls duration, but flush water use controls are still LEED acceptable.

Refusing to accept duration controls (run times must now match for both baseline and designs cases) would also imply that water duration controllers for landscaping should also be treated as schedule measures and not water savings measures.

Anyone else who practice green design see the failure by the USGBC to properly address water savings measures? Why pick on duration controls for WEc3 gpm devices only, while allowing quantity controls for WEc3 flush devices and WEc1 controllers as LEED-approved savings measures? The inconsistency makes no sense, but it is cast-in-concrete now for all LEED projects by the USGBC.

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Hernando Miranda Owner, Soltierra LLC Nov 27 2012 Guest 7159 Thumbs Up

After re-reading the LEED Reference Guide (RG) it is clear how wrong the reviewers are to deny duration controls for showers. The RG absolutely states automatic controls are an acceptable strategy for showers, and also sinks.

WE Overview Section: Water efficiency measures in commercial buildings can easily reduce water usage by 30% or more. … low-flow fixtures coupled with sensors and automatic controls can can save a minimum of 1 million gallons of water per year …

WEc3, Approach and Implementation: Effective methods to reduce 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 include: … installation and maintenance of automatic fixture sensorsAutomatic fixture sensors are motion detectors that automatically turn on and turn off lavatories, sinks, water closets, and urinals. Sensors can be hard wired or battery operated. or metering controls … on lavatory, sink, and shower fixtures …

WEc3, Tables 4 and 5, Conventional Lavatory and Kitchen Sink: For both the duration time is 12 seconds for the design case, and 15 seconds for the baseline case. [Note: Showers are not listed with controls, but the tables are only an example calculation.]

WEc3, Definitions: Metering Controls are generally manual on/automatic off controls which are used to limit the flow time of water. These types of controls are most commonly installed on lavatory faucets and on showers.

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Simon Chantal LEED Coordinator Martin Roy & Associés
Apr 12 2012
Guest
112 Thumbs Up

WEc3 under Version 1.0: Multiple showerhead calculation

The project got three different models of showerheads and the three models have different flow rates.

It is quite complex to determine the amount of person who will use the # 1 compared to the model # 2 or # 3.

Could we do a weighted average of rates according to each model and apply that average to all occupants? If no, what can we do to calculate the water use reduction?

Thanks!

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Tristan Roberts LEED AP BD+C, Editorial Director – LEEDuser, BuildingGreen, Inc. Aug 30 2012 LEEDuser Moderator

Simon, it's hard to say without more detail. Is there anything different about where the various models are installed? Are they installed in equal quantities?

The way fixture use is entered in your credit documentation would probably not allow the exact solution you suggest, but something close to that could be possible.

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Brian ORourke C&O Design
Feb 01 2012
Guest
150 Thumbs Up

Need a 1.1 GPF Toilet back outlet

I am looking for a 1.1 gpf toilet with back outlet that is not pressure assist. Does this even exist? seems like they are all pressure assist.

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Tristan Roberts LEED AP BD+C, Editorial Director – LEEDuser, BuildingGreen, Inc. Mar 06 2012 LEEDuser Moderator

Brian, I don't know of one, but perhaps you could call WaterSense and ask if floor outlet/rear outlet is part of the data they collect, and if so, they might help find one.

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Melissa Wrolstad Senior Project Manager, CodeGreen Solutions Mar 07 2012 LEEDuser Member 1850 Thumbs Up

Hi Brian,

American Standard just came out with a new line of low flow fixtures. Maybe this is what you're looking for:
http://www.americanstandard-us.com/products/productDetail.aspx?id=5381

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Brian ORourke C&O Design Mar 07 2012 Guest 150 Thumbs Up

Thanks very much Mellisa. This is what I was looking for.

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Susan Walter Sr Project Architect Wilmot/Sanz
Dec 07 2011
LEEDuser Expert
14152 Thumbs Up

Corrupt Form?

Has anyone else had problems with corrupt forms for this particular credit? I have to evaulate a construction change and the work around that i used for Design Review is no longer producing reliable results. The GBCI says they aren't supporting v2.2 forms. The sample forms available via the USGBC say sample all over them and won't save information. Once I was able to get around the pop up blocker, I could get that new form but it doesn't save as the new template. It is pretty frustrating. Anyone have a better work around?

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Melissa Wrolstad Senior Project Manager, CodeGreen Solutions Dec 07 2011 LEEDuser Member 1850 Thumbs Up

Select Alternative Compliance and upload your own unprotected Excel sheet that does the calculations. Make sure to include a narrative that explains in detail how your Excel sheet works.

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William Weaver Sustainability Practice Lead JLL
May 31 2011
LEEDuser Member
1267 Thumbs Up

Calculating for Shelled Spaces?

i am working on a 4-story mixed use facility. The upper three floors are multi-family residential, and the ground level is office and retail. The bulk of the retail floor is shelled space for future tenant upfit. For the shelled spaces, we have written tenant guidelines that provide maximum allowable flow/flush rates for fixtures, as well as provided specs for recommended fixtures. Additionally, the owner intends to require the tenants to pursue LEED CI or LEED Retail certification for their respective upfits through the lease agreement.

Given the square footage of shelled space, we can use the table in Appendix A of the LEED reference manual to calculate the projected 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 transients.

My question is, do we need to include the calculated FTE/transients in the water use reduction calculations since there is no actual occupancy or fixtures in place; or do we need to include them? If we are to include, do we calculate assuming they will use baseline fixtures, or can we use the recommended fixtures from the tenant guidelines?

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Tristan Roberts LEED AP BD+C, Editorial Director – LEEDuser, BuildingGreen, Inc. Jun 08 2011 LEEDuser Moderator

William, first question—what rating system are you using? Just checking since this seems like a CS question that's posted in the NC-v2.2 forum.

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William Weaver Sustainability Practice Lead, JLL Jun 08 2011 LEEDuser Member 1267 Thumbs Up

Tristan, this project is pursuing a LEED NC certification. It is a 4-story project. Three stories are completely fit out, and the lower level is split - partial occupancy for management office and amenity spaces, with the remainder (approx 13,000sf) being shell space for future retail and/or office upfit.

The future tenants of the shelled space will not have access to the restrooms in the remainder of the building, and therrefore will be required to fit out their own facilities within their space(s). The owner intends to require the future tenants to pursue LEED CI for their respective upfits via green lease, and we have written guidelines providing maximum allowable flow rates, and recommended fixtures.

As LEED NC is a whole building rating system, I cannot technically exclude the shelled volume and must account for it in our calculations with the rest of the building. My question is how do I go about accomodating that future occupancy within my calculations? Am I required to assume they will upfit their restrooms using baseline fixtures, or can I use the maximum allowable flow rates that we've provided in the tenant guidelines, provided that the owner submits a letter attesting that they will hold the tenant to those flow rates within the lease agreement?

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Tristan Roberts LEED AP BD+C, Editorial Director – LEEDuser, BuildingGreen, Inc. Jun 08 2011 LEEDuser Moderator

William, I think the best guidance on this is from CS Appendix 4 in the 2009 BD&C LEED reference guide. Yes, it's 2009 and yes it's CS, but I think the prescription there is perfectly logical for your situation.

Assume that tenant fixtures will be equivalent to the baseline, unless you're claiming savings in which case those must be supported by tenant sales and/or lease requirements.

Does that make sense?

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William Weaver Sustainability Practice Lead, JLL Jun 08 2011 LEEDuser Member 1267 Thumbs Up

Yes, that makes sense. But, if I understand Appendix 4 correctly, we would have to provide a copy of a lease agreement in order to claim savings? Would a signed letter from the owner stating that they will enforce those requirements through a binding tenant lease be sufficient for our needs to claim savings, or must we literally have a copy of the agreement?

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Tristan Roberts LEED AP BD+C, Editorial Director – LEEDuser, BuildingGreen, Inc. Sep 02 2011 LEEDuser Moderator

William, I don't know. I would think that the letter would work, but the leases would be more ironclad.

If you find out what works, let us know.

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William Weaver Sustainability Practice Lead, JLL Sep 02 2011 LEEDuser Member 1267 Thumbs Up

There is currently no tenant in place yet. The owner, being a non-profit, opted not to pay legal fees to generate a draft lease agreement until they have a prospective tenant lined up. So, we moved forward by submitting a signed letter from the owner attesting to enforcing requirements through a binding lease, as well as highly detailed tenant upfit guidelines. Fingers crossed...

I'm anticipating we'll receive award notification sometime mid-September. I'll post here what the determination is.

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David Mirabile LEED AP, BD+C
May 20 2011
Guest
873 Thumbs Up

Daily Average Building Occupants

I have submitted on a Campus building where we include staff as 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.'s(26) and Students (189) as the transient/students (makes sense right!). However, our review included the following comment:

"Revise the calculations as necessary to include the daily average building occupants." Am I missing something? We submitted our calculated FTE (26) and transient/student (189) occupancy numbers. Don't I just put them in each column under the occupancy breakdown portion on the template and be done with it? What else could they be asking here? Is daily average building occupants something different/separate? Thanks.

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William Weaver Sustainability Practice Lead, JLL May 31 2011 LEEDuser Member 1267 Thumbs Up

David - though I agree with your line of thinking, it is conceivable that there may be other visitors/transients to the building aside from the students. If you refer to the table in Appendix A in the reference manual, you can calculate transient occupancies for schools with the following formula:

# transients = gross square footageSum of the floor areas of the spaces within the building including basements, mezzanine and intermediate-floored tiers, and penthouses with headroom height of 7.5 ft or greater. It is measured from the exterior faces of exterior walls or from the centerline of walls separating buildings, but excluding covered walkways, open roofed-over areas, porches and similar spaces, pipe trenches, exterior terraces or steps, chimneys, roof overhangs, and similar features. / 150

So, if you had a 50,000sf facility, your total transient occupancy would be 50,000 / 150 = 333. (189 students plus 144 additional visitors/transients)

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David Mirabile LEED AP, BD+C May 31 2011 Guest 873 Thumbs Up

Thanks for your reply. Do you think that would solve their request for daily average building occupants? From my submitted template and attached calculations, they probably can't conclude or differentiate between students and "other" visitors becuase I included them as one in the same.

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William Weaver Sustainability Practice Lead, JLL May 31 2011 LEEDuser Member 1267 Thumbs Up

I can't speak to a higher-ed facility submitted under LEED NC, but under LEED for Schools the template clearly delineates between 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., Students, and Average Visitors.

My recommendation would be to provide a narrative that spells out the number of staff and students, and provides the calculation for transients. Refer to the table in Appendix 1 in your narrative so there's no question where your trnasient calculation came from.

On a side note, in my original response, I said the transient number included the student occupancy. The more I think about it, the transients may be in addition to the student population given that the LEED Schools template makes the delineation.

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David Mirabile LEED AP, BD+C May 31 2011 Guest 873 Thumbs Up

Yes, our facility willl be different than a k-12 type, it is more of a traching lab building where 1-2 classes/day may be brought in. Regarding the student vs. transient discussion, my confusion is in the template where you can list 1.) the FTEs, 2.) a student/visitor, 3.) customers, 4.) resident, and 5.) Other. So to me if they are not full-time they are calculated as a transient (at least in the template). That is why I wondered if the "daily building average" was including the transients into the FTE but the template surely is not set up that way to calculate your water usage, i think you are probably correct in stating that a narrative would help.

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Catalina Caballero Sustainability Coordinator, JALRW Eng. Group Inc. Feb 12 2013 LEEDuser Member 2253 Thumbs Up

What about Multifamily buildings? Our building contains

Residential Units = 72 units x 2 people = 144 persons
Multipurpose room = 2,288 sf / 15 people = 153 persons
Storage/mechanical rooms = 1,578 sf / 300 people = 6 persons
Total = 303 persons

How should we determine the transient/visitor count for the multipurpose rooms and mech rooms? Keep in mind that the multipurpose room is used by elederly people to play games and stuff, but it's not a regularly occupancy and some maybe residents while some can be outsiders. Is there rule of thumb?

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Kendall E Design Partners Inc.
May 05 2011
LEEDuser Member
381 Thumbs Up

Exemplary Performance ID Credits

The LEED v2.2 Reference Guide describes one added point for Exemplary PerformanceIn LEED, certain credits have established thresholds beyond basic credit achievement. Meeting these thresholds can earn additional points through Innovation in Design (ID) or Innovation in Operations (IO) points. As a general rule of thumb, ID credits for exemplary performance are awarded for doubling the credit requirements and/or achieving the next incremental percentage threshold. However, this rule varies on a case by case basis, so check the credit requirements. if water savings is at 40%. It then says that project teams may also achieve an ID credit if process and non-regulated water use savings is at least 10%. If we meet both of these criteria, does this mean we qualify for two ID points?

"In addition to earning WE Credits 3.1 and 3.2, project teams that achieve a projected water savings of 40% are eligible for an exemplary performance ID credit.

Project teams may also achieve an ID credit for demonstrating potable waterPotable water meets or exceeds EPA's drinking water quality standards and is approved for human consumption by the state or local authorities having jurisdiction; it may be supplied from wells or municipal water systems. use reduction in process and non-regulated water consuming fixtures. The calculation methodology for demonstrating process and non-regulated water savings is similar to the calculation outlined above for regulated water use. Project teams define reasonable usage assumptions and calculate design and baseline water consumption based on high efficiency and standard water use fixtures. Process and non-regulated water use savings is then compared to regulated water use. If the process and non-regulated water use savings is at least 10% of the total design regulated water use, the project team is eligible for an Innovation in Design point."

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David Hubka Director of Operations, Transwestern Sustainability Services May 05 2011 LEEDuser Expert 4407 Thumbs Up

Yes, if you meet both criteria you'll qualify for two ID credits.

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Michele Van Hyfte President, Monarch Design/Consulting May 12 2011 Guest 44 Thumbs Up

GBCI just denied my project a 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. ID credit because the project had also been awarded the WEc3 40% reduction ID credit. This conflicts with your interpretation. The review comment states: "The project has already achieved exemplary performanceIn LEED, certain credits have established thresholds beyond basic credit achievement. Meeting these thresholds can earn additional points through Innovation in Design (ID) or Innovation in Operations (IO) points. As a general rule of thumb, ID credits for exemplary performance are awarded for doubling the credit requirements and/or achieving the next incremental percentage threshold. However, this rule varies on a case by case basis, so check the credit requirements. of WEc3. Only one exemplary performance point is available for each credit." The comment further states: "Innovation in Design credits are not awarded when the strategy aids in the achievement of an existing credit." I may appeal this. Does anyone have a good idea how to justify it? Or has anyone actually achieved two ID credits for WEc3? Thank you!

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David Hubka Director of Operations, Transwestern Sustainability Services May 12 2011 LEEDuser Expert 4407 Thumbs Up

I would agree with their comment "Innovation in Design credits are not awarded when the strategy aids in the achievement of an existing credit"; however 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. consuming fixtures DO NOT contribute to the achievement of WE Credit #3.2.

On page #393 of the LEED NC ver2.2 reference guide it states that "no single strategy is eligible for more than one point". It does not say that only one exemplary performanceIn LEED, certain credits have established thresholds beyond basic credit achievement. Meeting these thresholds can earn additional points through Innovation in Design (ID) or Innovation in Operations (IO) points. As a general rule of thumb, ID credits for exemplary performance are awarded for doubling the credit requirements and/or achieving the next incremental percentage threshold. However, this rule varies on a case by case basis, so check the credit requirements. point is available for each credit.

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. usage and process water usage are,in my opinion, two completely seperate items. LEED NC ver2.2 does not include a credit strictly dedicated to process water consumption. However the LEED 2009 rating systems include a credit specifically for process / cooling tower water. Furthermore, BOTH the Water Use Reduction & Process Water Use Reduction credits of LEED 2009 allow project teams exemplary performance. Since ver2.2 does not specifically include a credit for process water usage it must lump it into the Water Use Reduction credit.

I disagree with the LEED reviewer and argue that project teams should not be penalized for "incompletions" of older rating systems.

I brought my soap box to LEEDuser today. :)
Hopefully you achieve success when interacting with the GBCI on this issue.
-Dave

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Lauren Sparandara Sustainability Manager Google
Mar 21 2011
LEEDuser Expert
15255 Thumbs Up

Exemplary Process Water Use Reduction

I received the following comment for one of my projects. However, I'm not sure I understand what the reviewer is asking us to calculate. We have provided calculations demonstrating savings in regulated water use (for WEc3) and calculations for our savings for 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. use. Do we now need to combine the two to see that our total savings is at least 10% or are they asking us to compare total savings *between* savings in regulated water use and savings in process water use?

LEED Comment:
The LEED Submittal Template has been submitted stating that the project achieves an exemplary performanceIn LEED, certain credits have established thresholds beyond basic credit achievement. Meeting these thresholds can earn additional points through Innovation in Design (ID) or Innovation in Operations (IO) points. As a general rule of thumb, ID credits for exemplary performance are awarded for doubling the credit requirements and/or achieving the next incremental percentage threshold. However, this rule varies on a case by case basis, so check the credit requirements. point for process water reduction. Calculations and product brochures have been provided.

However, calculations comparing the process water use to all regulated water use have not been provided. Please note that the strategy for achieving exemplary performance of WEc3 - Process Water Reduction is outlined on page 145 of the LEED NC v2.2 Reference Guide, Third Edition.

TECHNICAL ADVICE:
Please provide calculations demonstrating a 10% reduction in process and non-regulated water use savings, compared to the total deign regulated water use.

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Tristan Roberts LEED AP BD+C, Editorial Director – LEEDuser, BuildingGreen, Inc. Apr 23 2011 LEEDuser Moderator

Lauren, I am not looking at the Reference Guide right now, but my guess is that they are asking you to demonstrate a combined reduction of 10%.

Have you figured this out since you posted the question?

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Angie Plantz LEED, AP The Milnes Co., Inc.
Mar 10 2011
Guest
214 Thumbs Up

Hotel - FTE calculations - I can't seem to get this right.

I am working on a hotel, we have just completed the deisgn review and below are the comments from the USGBC. Can anyone give me some pointers?

The LEED Submittal Template has been provided stating that the project has reduced 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 by 33.6% from a calculated baseline design through the installation of low-flush water closets, low-flow urinals, low-flow lavatories, low-flow showers, and low-flow kitchen sinks. A narrative as also been provided.

However, 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. occupancy (107) is inconsistent with the FTE reported in SSc4.2: Alternative Transportation, Bicycle Storage and Changing Rooms (10). The hotel transient guests must be counted as residential occupants for the purposes of WEc3: Water Use Reduction. Please note that it is not expected that hotel transient guests will use a kitchen sink within each unit. Additionally, the EPAct of 1992 does not include janitor’s sinks in its regulation, and therefore must be excluded from the calculations.

TECHNICAL ADVICE:
Please provide a revised template and calculations with a revised daily occupancy. Ensure that the janitor's sinks have been excluded.

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David Posada Sustainability Manager, SS TAG member, GBD Architects Mar 10 2011 LEEDuser Expert 17414 Thumbs Up

Angie -
There's a link at the bottom of this page to the 2009 page where Mara discusses this in a few places. It sounds like you'll want to look into using fixture groups to differentiate between guest and staff water use. Also, look for the place to enter "Total number of residents" in PI form 3 - it's on page 3 after the FTE and Occupancy tables.

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Veronica Addison
Feb 24 2011
LEEDuser Member
168 Thumbs Up

Revised Template using both dual flush toilets and urinals

Does anyone have experience with the "revised template" available for this credit through LEED online?

I have a project with both dual flush toilets and low flow urinals. The restrooms for visitors all have urinals. FTEs have access to these restrooms and also several unisex restrooms. The revised template allows me to enter the % of males expected to use urinals. I am trying to figure out how this value is incorporated into the calculation. Do I also need to adjust the % of occupants column in Table 2.1 or does the "% of males expected to use urinals" already take this into account?

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Tristan Roberts LEED AP BD+C, Editorial Director – LEEDuser, BuildingGreen, Inc. Apr 23 2011 LEEDuser Moderator

Veronica, I just played around with the template a bit and it seems like if you vary the percentage of male bathrooms that have urinals, it changes the water use, even if you are not changing anything about daily uses, etc. So yes, it takes it into account.

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Melissa Wrolstad Senior Project Manager CodeGreen Solutions
Feb 09 2011
LEEDuser Member
1850 Thumbs Up

Default Core and Shell Museum Type FTE and Transient Values

We have a core and shell space that is a museum type. Where do we look to determine default gross square feet per occupant for employees and transients?

Note: None of the default occupancies in version 2009 come close to museum type.

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Tristan Roberts LEED AP BD+C, Editorial Director – LEEDuser, BuildingGreen, Inc. Feb 09 2011 LEEDuser Moderator

Melissa, would this be a better post for the CS WEc3 forum?

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Melissa Wrolstad Senior Project Manager, CodeGreen Solutions Feb 09 2011 LEEDuser Member 1850 Thumbs Up

Sorry Tristan, I believe that my initial question did not contain sufficient detail.

My project is an NC v2.2 project consisting of a residential tower with a core and shell space (approximately 22% of total GSF) that is most likely going to be built out into a museum. The residential tower and core and shell space core bathrooms have different types of plumbing fixtures. We are having difficulties with:

1.) Figuring out how to use the v2.2 LEED Online Template with multiple fixture and occupant types, AND
2.) Estimating number of transients for the core and shell space since there is not a type listed in “Table 1. Default Occupancy Numbers” in the LEED BD+C Reference Guide, Core & Shell Appendix 1.

Can we use the NC v2009 template in lieu of the v2.2 LEED Online Template, since it will let us easily incorporate multiple occupant and fixture types? AND, since this core and shell space is a portion of a primarily residential New Construction project, is the CS WEc3 forum the best place for us to track down an answer to the initial inquiry of how to estimate the number of transients and FTEs for a core and shell space that will most likely end up being museum space?

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Tristan Roberts LEED AP BD+C, Editorial Director – LEEDuser, BuildingGreen, Inc. Feb 24 2011 LEEDuser Moderator

Melissa, in terms of using the 2009 form I would ask GBCI if this is okay. It seems to make sense but I would ask in this situation.

Relative to estimating transients and FTEs, that's a difficult question. It seems unusual to build a C&S space for a museum without having some idea who the tenant will be. If you do have some idea, can you look at existing museum space that is similar and estimate from that?

There are so many different kinds of museums, it would seem hard to have a general rule for this.

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Janika McFeely Associate, Sustainability Specialist EHDD Architecture
Nov 02 2010
LEEDuser Member
859 Thumbs Up

Accounting for unisex restrooms

We have a project with a significant number of single accommodation unisex restrooms (no urinals) as well as multi-accommodation men's restrooms with urinals. Does anyone have any suggestion as to how to account for the unisex restrooms and urinals for males? Thanks very much!

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Tristan Roberts LEED AP BD+C, Editorial Director – LEEDuser, BuildingGreen, Inc. Nov 02 2010 LEEDuser Moderator

I believe you can address this by setting up fixture usage groups identifying the varying fixture groups and their anticipated usage. Make sense?

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Beckham Price Nov 05 2010 Guest 145 Thumbs Up

I'm confused. I have a similar issue on a project. Can I for example, nominate 2 of 4 unisex WC's for men and count them without urinals or can I disregard them entirely?

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Tristan Roberts LEED AP BD+C, Editorial Director – LEEDuser, BuildingGreen, Inc. Nov 05 2010 LEEDuser Moderator

Beckham, I don't know what you mean about disregarding them (what?) entirely.

If the WC's are unisex and will be marked as unisex then I don't see how you can count them as being just for men in your calcs.

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Janika McFeely Associate, Sustainability Specialist, EHDD Architecture Nov 05 2010 LEEDuser Member 859 Thumbs Up

Hi Tristan,
Can you use fixture groups with the 2.2 template? I asked for clarification from our review team and they are saying we should base the percentage on the number of restrooms accessible for males. For example, we have 6 multi-accommodation restrooms for males and 22 unisex restrooms therefore we only have 21% of male restrooms with urinals. This means we loose all of our water reduction points! I'm going to ask if we can base it on number of fixtures instead. Something to be aware of on projects with significant numbers of unisex toilets. If anyone has any other experience with this, I'd love to hear. Thanks.

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Beckham Price Nov 08 2010 Guest 145 Thumbs Up

Tristan,
Them is the WC's. I'm specifically wondering how I count WCs vs Men's Rooms with Urinals. The template requires a percentage of Men's Rooms with Urinals be input. Am I required to count the Unisex WCs as Men's Rooms without Urinals or can I disregard the Unisex WCs from the equation?

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Janika McFeely Associate, Sustainability Specialist, EHDD Architecture Nov 08 2010 LEEDuser Member 859 Thumbs Up

Hi Beckham,
Based on my recent experience with a reviewer, yes: you have to count unisex restrooms as accessible to men. Therefore if you have 5 unisex restrooms without urinals and 5 male restrooms with urinals, you'd have to put in that only 50% of men's restrooms have urinals. The template says that if your project has any urinals, you can not use the dual-flushA type of water-saving toilet that gives a choice of flushes depending on the type of waste — solid or liquid. option for males, which for our project means we loose all of our water points. I'm appealing this with our reviewer and have submitted two separate templates: one for just the percentage of male restrooms with urinals and one for everything else. I then added the two baselines and the two design case water usages and got a percentage from that. I think this is a more accurate reflection of usage and ironically it's almost the same percentage I got without all the number gymnastics. I'm not sure if they're going to accept though. I'll post and update once I hear back. Has anyone seen 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 about this kind of issue? I haven't been able to find one. Thanks

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Nancy Henderson Managing Partner, ArchEcology Jan 05 2011 LEEDuser Member 628 Thumbs Up

I have just run into the same review comment. We have a theatre with 2 unisex restrooms, 1 male restroom with urinals and 1 female restroom. The reviewer is saying we have 3 male restrooms and therefore only 33% of male restrooms with urinals. We also have dual flush toilets and they are requireing that we call 100% of the male use of the dual flush toilets as full flush. This seems totally skewed to me. We have a 50/50 gender split so half of the time the unisex restrooms will be used by women. This is a double penalty for having unisex restrooms. I guess I can understand calling them male, since they are accessible to males, but then the logic that there is NO half flush use of the dual flush toilets for males makes no sense.

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Janika McFeely Associate, Sustainability Specialist, EHDD Architecture Jan 05 2011 LEEDuser Member 859 Thumbs Up

Hi Nancy,
I finally heard back from the GBCI regarding my alternative compliance approach. They spent a long time looking at it apparently and provided the following guidance:

"First of all, please note that the percentage of male restrooms with urinals may be calculated based on the percentage of male fixtures in bathrooms that have urinals versus the total number of fixtures available to male occupants. For example, if your project has 20 male-accessible bathrooms with a total of 100 male fixtures (both urinals and toilets) and the breakdown is 5 bathrooms that contain a collective total of 85 fixtures (mix of toilets and urinals) and 15 bathrooms that contain a collective total of only 15 toilets (with no urinals), the percentage of male restrooms with urinals would be 85% (85 mixed fixtures / 100 total male fixtures). Please take care to include all fixtures that are available to males in your calculations (i.e. any unisex toilets must also be included in the total number of male fixtures in addition to those dedicated solely for male occupants).

In order to claim credit for dual-flushA type of water-saving toilet that gives a choice of flushes depending on the type of waste — solid or liquid. toilets in male restrooms when the project also includes urinals, you must perform a weighted calculation to determine an accurate percentage of males who will be utilizing the dual-flush option versus those that are expected to use only the full-flush option (i.e. those males who will be accessing the urinals). This number must be calculated using the percentage of male restrooms that was determined above. For example, assuming that you have 200 male occupants and that 20% of these occupants will have access to the urinals – these 40 people cannot be assumed to use the low-flush option of the toilet as they will be expected to be utilizing the urinals instead. However, you must calculate the amount of water they will generate using the full-flush option. To do this, you will need to perform the following calculations (numbers used as examples):

• Male Occupants with Urinals:
o Percentage of Male Restrooms with Urinals:
1. Count the total number of male-accessible fixtures: 100 Total Male Fixtures
2. Count the total number of fixtures in only the bathrooms that contain both urinals and toilets: 85 Mixed Bathroom Fixtures
3. Percentage of Male Restrooms = 85 Mixed Bathroom Fixtures / 100 Total Male Fixtures = 85% Male Bathrooms with Urinals
o Breakdown of 200 Male 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:
• Males Without Urinals: 200 Male FTE Occupants x 15% Male Restrooms Without Urinals = 30 occupants
• Males With Urinals: 200 Male FTE Occupants x 85% Male Restrooms With Urinals = 170 occupants

2A. Full-Flush Water Use:
a. Males Without Urinals: 30 FTE males-without-urinals x 1 uses/day = 30 uses/day x 1.6 gallons/flush = 48 Full-Flush Gallons/Day
b. Males With Urinals: 170 FTE males-with-urinals x 1 use/day = 170 uses/day x 1.6 gallons/flush = 272 Full-Flush Water Gallons/Day
i. Total Full-Flush Water Use = 48 gallons/day + 272 gallons/day = 320 Full-Flush Water Gallons/Day

2B. Low-Flush Water Use:
a. Males Without Urinals: 30 FTE males-without-urinals x 2 uses/day = 60 uses/day x 1.1 gallons/flush = 66 Low-Flush Gallons/Day
b. Males With Urinals: 0 Low-Flush Gallons/Day as these occupants are assumed to be using Urinals rather than Low-Flush Toilets
ii. Total Low-Flush Water Use = 66 gallons/day + 0 gallons/day = 66 Low-Flush Water Gallons/Day

3. Total Daily Male Water Used: 320 Full-Flush Water Gallons/day + 66 Low-Flow Water Gallons/day = 386 Total Daily Male Water/Day
a. Percentage of Males Using Full-Flush: 320 Full-Flush Water Gallons/Day / 386 Total Daily Male Water/day = 82.90% FTE Males Using Full-Flush
b. Percentage of Males Using Low-Flush: 100% Total Fixture Use – 82.90% Males Using Full-Flush = 17.1% FTE Males Using Low-Flush

Please note that if you have multiple types of occupants within the project such as Transients, Residents, etc, the calculations for Steps 2A and 2B will need to be performed for each individual group based on the group’s total male occupancy, the group’s access to the urinals, and the group’s appropriate usage rates. The Total Water Use found in these steps should include the sum total of each group’s individual water use so that the overall percentage is accurate for each group.

For the urinals, you would still need to use the default of 100% of Males use the Urinals. For the design final review, please provide a copy of this email correspondence to confirm usage of this calculation method, separate calculations documenting the weighted fixture calculations provided in the Template, and a revised Template to show the weighted percentages for the male use of the dual-flush toilets. "

While this helped, I was still confused as to how to calculate the total savings and don't want to do all the calculations separately by hand when it seems that the template can handle it. I therefore replied with a second proposal that I split the occupancy between male restrooms with urinals on one template (using their guidance on percentage of fixtures to determine % of occupants applicable) and then womens and unisex on another. Haven't heard back yet but will let you know what they say. Ironically, the percent water savings was about the same from the split template and the initial version i submitted. It should be more straightforward!

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Nancy Henderson Managing Partner, ArchEcology Jan 06 2011 LEEDuser Member 628 Thumbs Up

Wow - that is indeed complicated! Thanks for the update it will definitely help me.

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Ruben Porter Feb 11 2014 Guest 97 Thumbs Up

Has anyone had any success with this calculated approach? I'm guessing that once you calculate the percentage of FTEFull-time equivalent (FTE) represents a regular building occupant who spends 8 hours a day (40 hours a week) in the project building. Part-time or overtime occupants have FTE values based on their hours per day divided by 8 (or hours per week divided by 40). Transient Occupants can be reported as either daily totals or as part of the FTE. Residential occupancy should be estimated based on the number and size of units. Core and Shell projects should refer to the default occupancy table in the Reference Guide appendix. All occupant assumptions must be consistent across all credits in all categories. using low flow flush and full flow, you would put that percentage under the "Percent of Occupants" column on Table 2.1.

From what I understand we should leave the "Percentage of male occupants expected to use urinals" at 100%, but do I need to adjust the urinal FTE?

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Gayle Borst President / CEO Stewardship, Inc.
Sep 01 2010
Guest
157 Thumbs Up

FTE calculation for a fire station

We have a municipal fire / EMS station with maximum possible occupancy of 20 (16 firefighters and 4 EMS personnel) at any given time. They operate on a 24 hour shift cycle, so we think we must use 60 (20 x 3 8-hour periods) as our total 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 this credit. Do you agree?

Part 2 of my question: Based on the City's current and projected gender ratios, this new building is designed for a gender ratio of 3 men to 1 woman. If and when the gender ratio equalizes,significant structural changes would be required to the building's locker rooms and dorm rooms. Our GBCI design phase reviewer commented: "Please note, 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." Should we bite the bullet and use 50/50 gender ratio, or should we present our case for 3:1? (Our mechanical engineer failed to submit any explanation for the unequal ratio for the design phase review.)

Part 3: We used only FTE water uses rather than both FTE and Residential, per Table 2 in the Reference Guide because we consider this building as all "commercial" use rather than commercial and residential. However, the GBCI HVAC reviewer seems to think the building should be modeled as part commercial and part residential because of the dorm rooms. Our feeling is that the firefighters are at work when the occupy this building, the don't reside there. When they do sleep there, it is incidental to their job - They are "working", not "living" while they use the dorms. I ask this question here because we have to be consistent across the credits. Do you know how other fire station projects have dealt with this?
Thanks for any help anyone can offer.

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Tristan Roberts LEED AP BD+C, Editorial Director – LEEDuser, BuildingGreen, Inc. Sep 02 2010 LEEDuser Moderator

1) Yes, I agree.

2) Based on your note that the unequal staffing was not explained in the initial submission, and since your description makes it sounds like the situation meets the threshold the reviewer described, you have a good shot at justifying the unequal ratio and should go for that.

3) From what I have seen from GBCI, fire stations, or at least the dorm part, are considered "residential" for EAc1, i.e. HVAC, because EAc1 references ASHRAE 90.1 in which those dorms are residential.

With WEc3, GBCI is prepared to see a fire station as either residential or commercial depending on the project specifics. One of the factors they look at is shift length, and it sounds like you make a good case that this is more of a "commercial" situation than residential.

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