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LEED v4
Data Centers – NC
Water Efficiency
Indoor water use reduction

LEED CREDIT

Data-Centers-NC-v4 WEp2: Indoor water use reduction Required

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View the LEED v4.1 version of this credit »

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emily reese moody

LEED AP BD+C, GGP, GPCP, ENV SP, Fitwel Ambassador, GCP

Jacobs
Sustainability Director, Certifications & Compliance

SPECIAL REPORT

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© Copyright U.S. Green Building Council, Inc. All rights reserved.

Intent

To reduce indoor water consumption.

Requirements

Building Water Use
For the fixtures and fittings listed in Table 1, as applicable to the project scope, reduce aggregate water consumption by 20% from the baseline. Base calculations on the volumes and flow rates shown in Table 1. All newly installed toilets, urinals, private lavatory faucets, and showerheads that are eligible for labeling must be WaterSense labeled (or a local equivalent for projects outside the U.S.).
Table 1. Baseline water consumption of fixtures and fittings
Commercial Fixtures, Fittings, and Appliances Current Baseline (IP Units) Current Baseline (SI units)
Water closets (toilets)* 1.6 gallons per flush (gpf) 6 liters per flush (lpf)
Urinal* 1.0 (gpf) 3.8 lpf
Public lavatory (restroom) faucet 0.5 gpm at 60 psi all others except private applications 1.9 lpm at 415 kPa, all others except private applications
Private lavatory faucet* 2.2 gpm at 60 psi 8.3 lpm at 415 kPa
Kitchen faucet (excluding faucets used exclusively for filling operations) 2.2 gpm at 60 psi 8.3 lpm at 415 kPa
Showerhead* 2.5 gpm at 80 psi per shower stall 9.5 lpm at 550 kPa per shower stall
* WaterSense label available for this product type gpf = gallons per flush gpm = gallons per minute psi = pounds per square inch lpf = liters per flush lpm = liters per minute kPa = kilopascals
Appliance and process water use
Install appliances, equipment, and processes within the project scope that meet the requirements listed in the tables below .
Table 2. Standards for appliances
Appliance Requirement
Residential clothes washers ENERGY STAR or performance equivalent
Commercial clothes washers CEE Tier 3A
Residential dishwashers (standard and compact) ENERGY STAR or performance equivalent
Prerinse spray valves ≤ 1.3 gpm (4.9 lpm)
Ice machine ENERGY STAR or performance equivalent and use either air-cooled or closed-loop cooling, such as chilled or condenser water system
gpm = gallons per minute
lpm = liters per minute
Table 3. Standards for processes
Process Requirement
Heat rejection and cooling No once-through cooling with potable water for any equipment or appliances that reject heat
Cooling towers and evaporative condensers Equip with:
  • makeup water meters
  • conductivity controllers and overflow alarms
  • efficient drift eliminators that reduce drift to maximum of 0.002% of recirculated water volume for counterflow towers and 0.005% of recirculated water flow for cross-flow towers
See all forum discussions about this credit »

What does it cost?

Cost estimates for this credit

On each BD+C v4 credit, LEEDuser offers the wisdom of a team of architects, engineers, cost estimators, and LEED experts with hundreds of LEED projects between then. They analyzed the sustainable design strategies associated with each LEED credit, but also to assign actual costs to those strategies.

Our tab contains overall cost guidance, notes on what “soft costs” to expect, and a strategy-by-strategy breakdown of what to consider and what it might cost, in percentage premiums, actual costs, or both.

This information is also available in a full PDF download in The Cost of LEED v4 report.

Learn more about The Cost of LEED v4 »

Frequently asked questions

Not all fixture types can get the WaterSense label. Which fixtures do we need to ensure have the WaterSense label for our project?

The answer to this question is available to LEEDuser premium members. Start a free trial »

(If you're already a premium member, log in here.)

How does the CEE Tier 3A criteria for commercial clothes washers compare to ENERGY STAR certified washers?

The answer to this question is available to LEEDuser premium members. Start a free trial »

(If you're already a premium member, log in here.)

Is the WaterSense label really required, even if a non-labeled fixture has a comparable flush or flow rate?

The answer to this question is available to LEEDuser premium members. Start a free trial »

(If you're already a premium member, log in here.)
See all forum discussions about this credit »

Addenda

4/9/2021 – Updated: 4/19/2021
Reference Guide Correction
Description of change:
Under Step 2. Select Watersense-Labeled Products:
Delete "or showers" from the sentence "Newly installed aerators or flow restrictors added to private lavatories or showers must be WaterSense labeled.”

Campus Applicable
No
Internationally Applicable:
No
10/1/2014 – Updated: 12/3/2019
Reference Guide Correction
Description of change:
Replace "Projects in unlisted countries must comply with the 20%-below-baseline requirement but have no additional performance requirements" with: "Project outside the U.S. must meet WaterSense flush and flow rates."

In the related “International Water Labeling Programs” Guidance Document (http://www.usgbc.org/resources/international-water-labeling-programs), edit the note at the bottom of the document to read:
“Note: countries without a listed labeling program must meet the flush and flow requirements of “Table 6. Maximum installed flush or flow rates for prescriptive path” listed in the Step-by-Step Guidance section of the LEED Reference Guide.
Campus Applicable
No
Internationally Applicable:
Yes
7/25/2019 – Updated: 7/30/2019
Rating System Correction
Description of change:
Add an asterisk to the end of "private lavatory faucets" in the first column of the table.
Campus Applicable
No
Internationally Applicable:
No
4/6/2018 – Updated: 4/24/2018
Reference Guide Correction
Description of change:
Add the following content to the end of the "International Tips" section:

“Projects served by water supply pressures different than specified in LEED v4 may install pressure compensating aerators in flow fixtures to achieve the desired flow rate without compromising user satisfaction.”
Campus Applicable
No
Internationally Applicable:
Yes
4/6/2018 – Updated: 4/23/2018
Reference Guide Correction
Description of change:
ID+C reference guide, STEP-BY-STEP GUIDANCE section:

Under Step 4. Select High-Efficiency Appliances, add the following content after the sentence that begins "ENERGY STAR may not be readily available in all areas": "Existing appliances intended for reuse in the project are not required to meet the requirements in Table 2. Standards for appliances"

Under Step 5. Design Process Water Systems, add the following content after the sentence that begins "Where applicable, select and design appliances and equipment": "Existing equipment intended for reuse in the project is not required to meet the requirements in Table 3. Standards for processes."

BD+C reference guide, STEP-BY-STEP GUIDANCE section:

Under Step 4. Select High-Efficiency Appliances, add the following content after the sentence that begins "Select appliances that meet the labeling or performance requirements":
"Existing appliances intended for reuse in the project are not required to meet the requirements in Table 2. Standards for appliances"

Under Step 5. Design Process Water Systems, add the following content after the sentence that begins "Where applicable, select and design appliances and equipment": "Existing equipment intended for reuse in the project is not required to meet the requirements in Table 3. Standards for processes."
Campus Applicable
No
Internationally Applicable:
Yes
1/27/2017 – Updated: 10/12/2017
Reference Guide Correction
Description of change:
BD+C, ID+C reference guide: Revise the Group Approach section to read: "Eligible. The percentage reduction can be based on the total combined water use reduction in all LEED project buildings. If nonpotable water systems will be shared by multiple projects, ensure adequate supply to meet the demands of all projects using nonpotable water. The nonpotable water may not be double-counted among projects. Submit separate documentation for each building, as required for WE Prerequisite Indoor Water Use Reduction. "

O+M reference guide: Revise the Group Approach section to read: "Eligible. The percentage reduction can be based on the total combined water use reduction in all LEED project buildings. The baseline adjustment for year of substantial system completion should be averaged based on all plumbing fixtures in all buildings. If nonpotable water systems will be shared by multiple projects, ensure adequate supply to meet the demands of all projects using nonpotable water. The nonpotable water may not be double-counted among projects. Submit separate documentation for each building, as required for WE Prerequisite Indoor Water Use Reduction. "
Campus Applicable
Yes
Internationally Applicable:
Yes
1/27/2017 – Updated: 1/27/2017
Form Update
Description of change:
modified flow fixture calculation to allow for savings on total daily water use from non-default duration (v03)
Campus Applicable
No
Internationally Applicable:
No
4/5/2016 – Updated: 4/7/2016
Reference Guide Correction
Description of change:
Compliance Path 1. Prescriptive Achievement (Prerequisite Only), Step 2. Collect manufacturers’ information
Change the last sentence to read: “A plumbing fixture schedule is acceptable, provided it contains the fixture manufacturer, model, flush or flow rate information, and the WaterSense designation where applicable.”
Campus Applicable
Yes
Internationally Applicable:
Yes
4/5/2016 – Updated: 4/7/2016
Reference Guide Correction
Description of change:
Revise the second sentence to read: “If the spaces use different fixtures or have dramatically different patterns of occupancy or varying annual days of operation, complete the indoor water use calculator with a separate fixture group for each space type.”
Campus Applicable
Yes
Internationally Applicable:
Yes
10/1/2014 – Updated: 2/14/2015
Form Update
Description of change:
For CS projects only, added tenant lease agreement upload and narrative describing future tenant plumbing fixtures to WE Credit Indoor Water Use Reduction section. Throughout form, added instructional notes clarifying when field values should be based on developer-installed fixtures versus future tenant plumbing fixtures.
Campus Applicable
Yes
Internationally Applicable:
Yes
10/1/2014 – Updated: 2/14/2015
Reference Guide Correction
Description of change:
Add Additions to Project Type Variations –

Additions
For credit compliance, include in the credit documentation all plumbing fixtures necessary to meet the occupants’ needs whether they will be installed as part of the project’s scope of work or not. Include at a minimum all necessary restroom fixtures (toilets, urinals, and lavatories) to meet the project occupants’ needs, and showers when seeking LT Credit Bicycle Facilities. The WaterSense label requirement does not apply to fixtures that are outside of the scope of the LEED project.
Campus Applicable
No
Internationally Applicable:
Yes
10/1/2014 – Updated: 2/14/2015
Form Update
Description of change:
Fixed errors in previous version including uses per day calculation. Added override functions for special circumstances, modified built-in dual flush calculator, added custom naming of tabs and streamlined output fields

Added Neighborhood Development calculations
Campus Applicable
No
Internationally Applicable:
Yes
7/1/2014 – Updated: 2/14/2015
Reference Guide Correction
Description of change:
Remove "seawater" from list of untreated water sources ineligible for this credit.
Add "treated seawater" to the list of acceptable alternative water sources, behind stormwater.
Campus Applicable
No
Internationally Applicable:
Yes
1/27/2017
LEED Interpretation
Inquiry:

Can automated-maintenance urinals be considered "waterless" for the purposes of WE prerequisite and credit Indoor Water Use Reduction?

Ruling:

Yes, automated maintenance urinals with water use not to exceed 150 gallons (568 liters) annually can be considered as waterless urinals for the purposes of credit achievement calculations in LEED v4 WE prerequisite and credit Indoor Water Use Reduction. Do not include the volume of water used by these urinals in the LEED v4 Indoor Water Use Calculator (they can be excluded, or considered to have a water use of 0 gallons/liters). Projects must also submit manufacturer documentation showing the annual volume of water used by the urinals.

Campus Applicable
Yes
Internationally Applicable:
Yes
See all forum discussions about this credit »

Documentation toolkit

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LEEDuser’s Documentation Toolkit is loaded with calculators to help assess credit compliance, tracking spreadsheets for materials, sample templates to help guide your narratives and LEED Online submissions, and examples of actual submissions from certified LEED projects for you to check your work against. To get your plaque, start with the right toolkit.

LEEDuser expert

headshot

emily reese moody

LEED AP BD+C, GGP, GPCP, ENV SP, Fitwel Ambassador, GCP

Jacobs
Sustainability Director, Certifications & Compliance

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Our editors have written a detailed analysis of nearly every LEED credit, and LEEDuser premium members get full access. We’ll tell you whether the credit is easy to accomplish or better left alone, and we provide insider tips on how to document it successfully.

USGBC logo

© Copyright U.S. Green Building Council, Inc. All rights reserved.

Intent

To reduce indoor water consumption.

Requirements

Building Water Use
For the fixtures and fittings listed in Table 1, as applicable to the project scope, reduce aggregate water consumption by 20% from the baseline. Base calculations on the volumes and flow rates shown in Table 1. All newly installed toilets, urinals, private lavatory faucets, and showerheads that are eligible for labeling must be WaterSense labeled (or a local equivalent for projects outside the U.S.).
Table 1. Baseline water consumption of fixtures and fittings
Commercial Fixtures, Fittings, and Appliances Current Baseline (IP Units) Current Baseline (SI units)
Water closets (toilets)* 1.6 gallons per flush (gpf) 6 liters per flush (lpf)
Urinal* 1.0 (gpf) 3.8 lpf
Public lavatory (restroom) faucet 0.5 gpm at 60 psi all others except private applications 1.9 lpm at 415 kPa, all others except private applications
Private lavatory faucet* 2.2 gpm at 60 psi 8.3 lpm at 415 kPa
Kitchen faucet (excluding faucets used exclusively for filling operations) 2.2 gpm at 60 psi 8.3 lpm at 415 kPa
Showerhead* 2.5 gpm at 80 psi per shower stall 9.5 lpm at 550 kPa per shower stall
* WaterSense label available for this product type gpf = gallons per flush gpm = gallons per minute psi = pounds per square inch lpf = liters per flush lpm = liters per minute kPa = kilopascals
Appliance and process water use
Install appliances, equipment, and processes within the project scope that meet the requirements listed in the tables below .
Table 2. Standards for appliances
Appliance Requirement
Residential clothes washers ENERGY STAR or performance equivalent
Commercial clothes washers CEE Tier 3A
Residential dishwashers (standard and compact) ENERGY STAR or performance equivalent
Prerinse spray valves ≤ 1.3 gpm (4.9 lpm)
Ice machine ENERGY STAR or performance equivalent and use either air-cooled or closed-loop cooling, such as chilled or condenser water system
gpm = gallons per minute
lpm = liters per minute
Table 3. Standards for processes
Process Requirement
Heat rejection and cooling No once-through cooling with potable water for any equipment or appliances that reject heat
Cooling towers and evaporative condensers Equip with:
  • makeup water meters
  • conductivity controllers and overflow alarms
  • efficient drift eliminators that reduce drift to maximum of 0.002% of recirculated water volume for counterflow towers and 0.005% of recirculated water flow for cross-flow towers

Cost estimates for this credit

On each BD+C v4 credit, LEEDuser offers the wisdom of a team of architects, engineers, cost estimators, and LEED experts with hundreds of LEED projects between then. They analyzed the sustainable design strategies associated with each LEED credit, but also to assign actual costs to those strategies.

Our tab contains overall cost guidance, notes on what “soft costs” to expect, and a strategy-by-strategy breakdown of what to consider and what it might cost, in percentage premiums, actual costs, or both.

This information is also available in a full PDF download in The Cost of LEED v4 report.

Learn more about The Cost of LEED v4 »

In the end, LEED is all about documentation. LEEDuser’s Documentation Toolkit, for premium members only, saves you time and helps you avoid mistakes with:

  • Calculators to help assess credit compliance.
  • Tracking spreadsheets for materials purchases.
  • Spreadsheets and forms to give to subs and other team members.
  • Guidance documents on arcane LEED issues.
  • Sample templates to help guide your narratives and LEED Online submissions.
  • Examples of actual submissions from certified LEED projects.

Not all fixture types can get the WaterSense label. Which fixtures do we need to ensure have the WaterSense label for our project?

The answer to this question is available to LEEDuser premium members. Start a free trial »

(If you're already a premium member, log in here.)

How does the CEE Tier 3A criteria for commercial clothes washers compare to ENERGY STAR certified washers?

The answer to this question is available to LEEDuser premium members. Start a free trial »

(If you're already a premium member, log in here.)

Is the WaterSense label really required, even if a non-labeled fixture has a comparable flush or flow rate?

The answer to this question is available to LEEDuser premium members. Start a free trial »

(If you're already a premium member, log in here.)
4/9/2021 – Updated: 4/19/2021
Reference Guide Correction
Description of change:
Under Step 2. Select Watersense-Labeled Products:
Delete "or showers" from the sentence "Newly installed aerators or flow restrictors added to private lavatories or showers must be WaterSense labeled.”

Campus Applicable
No
Internationally Applicable:
No
10/1/2014 – Updated: 12/3/2019
Reference Guide Correction
Description of change:
Replace "Projects in unlisted countries must comply with the 20%-below-baseline requirement but have no additional performance requirements" with: "Project outside the U.S. must meet WaterSense flush and flow rates."

In the related “International Water Labeling Programs” Guidance Document (http://www.usgbc.org/resources/international-water-labeling-programs), edit the note at the bottom of the document to read:
“Note: countries without a listed labeling program must meet the flush and flow requirements of “Table 6. Maximum installed flush or flow rates for prescriptive path” listed in the Step-by-Step Guidance section of the LEED Reference Guide.
Campus Applicable
No
Internationally Applicable:
Yes
7/25/2019 – Updated: 7/30/2019
Rating System Correction
Description of change:
Add an asterisk to the end of "private lavatory faucets" in the first column of the table.
Campus Applicable
No
Internationally Applicable:
No
4/6/2018 – Updated: 4/24/2018
Reference Guide Correction
Description of change:
Add the following content to the end of the "International Tips" section:

“Projects served by water supply pressures different than specified in LEED v4 may install pressure compensating aerators in flow fixtures to achieve the desired flow rate without compromising user satisfaction.”
Campus Applicable
No
Internationally Applicable:
Yes
4/6/2018 – Updated: 4/23/2018
Reference Guide Correction
Description of change:
ID+C reference guide, STEP-BY-STEP GUIDANCE section:

Under Step 4. Select High-Efficiency Appliances, add the following content after the sentence that begins "ENERGY STAR may not be readily available in all areas": "Existing appliances intended for reuse in the project are not required to meet the requirements in Table 2. Standards for appliances"

Under Step 5. Design Process Water Systems, add the following content after the sentence that begins "Where applicable, select and design appliances and equipment": "Existing equipment intended for reuse in the project is not required to meet the requirements in Table 3. Standards for processes."

BD+C reference guide, STEP-BY-STEP GUIDANCE section:

Under Step 4. Select High-Efficiency Appliances, add the following content after the sentence that begins "Select appliances that meet the labeling or performance requirements":
"Existing appliances intended for reuse in the project are not required to meet the requirements in Table 2. Standards for appliances"

Under Step 5. Design Process Water Systems, add the following content after the sentence that begins "Where applicable, select and design appliances and equipment": "Existing equipment intended for reuse in the project is not required to meet the requirements in Table 3. Standards for processes."
Campus Applicable
No
Internationally Applicable:
Yes
1/27/2017 – Updated: 10/12/2017
Reference Guide Correction
Description of change:
BD+C, ID+C reference guide: Revise the Group Approach section to read: "Eligible. The percentage reduction can be based on the total combined water use reduction in all LEED project buildings. If nonpotable water systems will be shared by multiple projects, ensure adequate supply to meet the demands of all projects using nonpotable water. The nonpotable water may not be double-counted among projects. Submit separate documentation for each building, as required for WE Prerequisite Indoor Water Use Reduction. "

O+M reference guide: Revise the Group Approach section to read: "Eligible. The percentage reduction can be based on the total combined water use reduction in all LEED project buildings. The baseline adjustment for year of substantial system completion should be averaged based on all plumbing fixtures in all buildings. If nonpotable water systems will be shared by multiple projects, ensure adequate supply to meet the demands of all projects using nonpotable water. The nonpotable water may not be double-counted among projects. Submit separate documentation for each building, as required for WE Prerequisite Indoor Water Use Reduction. "
Campus Applicable
Yes
Internationally Applicable:
Yes
1/27/2017 – Updated: 1/27/2017
Form Update
Description of change:
modified flow fixture calculation to allow for savings on total daily water use from non-default duration (v03)
Campus Applicable
No
Internationally Applicable:
No
4/5/2016 – Updated: 4/7/2016
Reference Guide Correction
Description of change:
Compliance Path 1. Prescriptive Achievement (Prerequisite Only), Step 2. Collect manufacturers’ information
Change the last sentence to read: “A plumbing fixture schedule is acceptable, provided it contains the fixture manufacturer, model, flush or flow rate information, and the WaterSense designation where applicable.”
Campus Applicable
Yes
Internationally Applicable:
Yes
4/5/2016 – Updated: 4/7/2016
Reference Guide Correction
Description of change:
Revise the second sentence to read: “If the spaces use different fixtures or have dramatically different patterns of occupancy or varying annual days of operation, complete the indoor water use calculator with a separate fixture group for each space type.”
Campus Applicable
Yes
Internationally Applicable:
Yes
10/1/2014 – Updated: 2/14/2015
Form Update
Description of change:
For CS projects only, added tenant lease agreement upload and narrative describing future tenant plumbing fixtures to WE Credit Indoor Water Use Reduction section. Throughout form, added instructional notes clarifying when field values should be based on developer-installed fixtures versus future tenant plumbing fixtures.
Campus Applicable
Yes
Internationally Applicable:
Yes
10/1/2014 – Updated: 2/14/2015
Reference Guide Correction
Description of change:
Add Additions to Project Type Variations –

Additions
For credit compliance, include in the credit documentation all plumbing fixtures necessary to meet the occupants’ needs whether they will be installed as part of the project’s scope of work or not. Include at a minimum all necessary restroom fixtures (toilets, urinals, and lavatories) to meet the project occupants’ needs, and showers when seeking LT Credit Bicycle Facilities. The WaterSense label requirement does not apply to fixtures that are outside of the scope of the LEED project.
Campus Applicable
No
Internationally Applicable:
Yes
10/1/2014 – Updated: 2/14/2015
Form Update
Description of change:
Fixed errors in previous version including uses per day calculation. Added override functions for special circumstances, modified built-in dual flush calculator, added custom naming of tabs and streamlined output fields

Added Neighborhood Development calculations
Campus Applicable
No
Internationally Applicable:
Yes
7/1/2014 – Updated: 2/14/2015
Reference Guide Correction
Description of change:
Remove "seawater" from list of untreated water sources ineligible for this credit.
Add "treated seawater" to the list of acceptable alternative water sources, behind stormwater.
Campus Applicable
No
Internationally Applicable:
Yes
1/27/2017
LEED Interpretation
Inquiry:

Can automated-maintenance urinals be considered "waterless" for the purposes of WE prerequisite and credit Indoor Water Use Reduction?

Ruling:

Yes, automated maintenance urinals with water use not to exceed 150 gallons (568 liters) annually can be considered as waterless urinals for the purposes of credit achievement calculations in LEED v4 WE prerequisite and credit Indoor Water Use Reduction. Do not include the volume of water used by these urinals in the LEED v4 Indoor Water Use Calculator (they can be excluded, or considered to have a water use of 0 gallons/liters). Projects must also submit manufacturer documentation showing the annual volume of water used by the urinals.

Campus Applicable
Yes
Internationally Applicable:
Yes

LEEDuser expert

headshot

emily reese moody

LEED AP BD+C, GGP, GPCP, ENV SP, Fitwel Ambassador, GCP

Jacobs
Sustainability Director, Certifications & Compliance

See all LEEDuser forum discussions about this credit » Unsubscribe from discussions about Data-Centers-NC-v4 WEp2 View the LEED v4.1 version of this credit