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LEED v2009
Schools
Water Efficiency
Water Use Reduction

LEED CREDIT

Schools-2009 WEc3: Water Use Reduction 2-4 points

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LEEDuser expert

Carlie Bullock-Jones

Ecoworks Studio
Principal

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USGBC logo

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

Intent

To further increase water efficiency within buildings to reduce the burden on municipal water supply and wastewater systems.

Requirements

Employ strategies that in aggregate use less water than the water use baseline calculated for the building (not including irrigation). The minimum water savings percentage for each point threshold is as follows:

% Reduction Points
30% 2
35% 3
40% 4

Calculate the baseline according to the commercial and/or residential baselines outlined below1. Calculations are based on estimated occupant usage and must include only the following fixtures and fixture fittings (as applicable to the project scope): water closets, urinals, lavatory faucets, showers, kitchen sink faucets and pre-rinse spray valves. [Europe ACP: Water Use Baseline]

Commercial Fixtures, Fittings, and Appliances Current Baseline (Imperial Units) Current Baseline (Metric units)
Commercial Toilets 1.6 gallons per flush (gpf)*
Except blow-out fixtures: 3.5 (gpf)
6 liters per flush (lpf)
Except blow-out fixtures: 13 lpf
Commercial Urinals 1.0 (gpf) 4 lpf
Commercial Lavatory (Restroom) Faucets 2.2 gallons per minute (gpm) at 60 pounds per
square inch (psi), private applications only (hotel
or motel guest rooms, hospital patient rooms)
0.5 (gpm) at 60 (psi)** all others except private
applications
0.25 gallons per cycle for metering faucets
8.5 liters per minute (lpm) at 4 bar (58 psi),
private applications only (hotel or motel guest
rooms, hospital patient rooms)
2.0 lpm at 4 bar (58 psi), all others except
private applications
1 liter per cycle for metering faucets
Showerheads 2.5 (gpm) at 80 (psi) per shower stall **** 9.5 lpm at 5 bar (58 psi)
For projects with commercial pre-rinse spray valves, the flow rate must comply with the asME a112.18.1 standard of 1.6 gpm or less.

Residential fixtures, fittings, and appliances Current baseline (imperial units) Current baseline (metric units)
Residential toilets 1.6 (gpf)*** 6 liters per flush (lpf)
Except blow-out fixtures: 13 lpf
Residential lavatory (bathroom) faucets 2.2 (gpm) at 60 psi 4 lpm
8.5 lpm at 4 bar (58 psi), private applications only
(hotel or motel guest rooms, hospital patient rooms)
2.0 lpm at 4 bar (58 psi), all others except private
applications
1 liter per cycle for metering faucets
Residential kitchen faucet
Residential showerheads 2.5 (gpm) at 80 (psi) per shower stall**** flow rate ≤ 6.1 lpm
(no pressure specified; no performance requirement)
* EPAct1992 standard for toilets applies to both commercial and residential models.
** in addition to Epact requirements, the american society of Mechanical Engineers standard for public lavatory faucets is 0.5 gpm at 60 psi (2.0 lpm at 4 bar (58 psi)) (asME a112.18.1-2005). this maximum has been incorporated into the national uniform plumbing Code and the international plumbing Code.
*** EPAct 1992 standard for toilets applies to both commercial and residential models.
**** residential shower compartment (stall) in dwelling units: the total allowable flow rate from all flowing showerheads at any given time, including rain systems, waterfalls, bodysprays, bodyspas and jets, must be limited to the allowable showerhead flow rate as specified above (2.5 gpm) per shower compartment, where the floor area of the shower compartment is less than 2,500 square inches (1.5 square meters). for each increment of 2,500 square inches (1.5 square meters) of floor area thereafter or part thereof, an additional showerhead with total allowable flow rate from all flowing devices equal to or less than the allowable flow rate as specified above must be allowed. Exception: showers that emit recirculated nonpotable water originating from within the shower compartment while operating are allowed to exceed the maximum as long as the total potable water flow does not exceed the flow rate as specified above.

The following fixtures, fittings and appliances are outside the scope of the water use reduction calculation:

  • Commercial Steam Cookers
  • Commercial Dishwashers
  • Automatic Commercial Ice Makers
  • Commercial (family-sized) Clothes Washers
  • Residential Clothes Washers
  • Standard and Compact Residential Dishwashers

Alternative Compliance Paths (ACPs)

Europe ACP: Water Use Baseline

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

See all forum discussions about this credit »

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Frequently asked questions

In LEED review comments I've been referred to the Water Use Reduction Additional Guidance document. I didn't know this was a required reference document.

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Should I include bar sinks? What about mop sinks or janitor sinks? Swimming pools? Safety showers? Bidets? Tub spouts?

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We provided new showers in our project to comply with the alternative transportation credit. Should they be considered in WEp1 calculations?

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Can you explain the 12-second duration for metering faucets?

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Can I use a nonpotable water source to contribute to WEp1 compliance?

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Our project does not have any eligible water fixtures in the project boundary. Can we comply with WEp1?

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We are having trouble finding EPAct-compliant fixtures. Is that a problem?

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Where can I find a clear meaning of "public" and "private" as relevant to lavatory faucets?

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Our project is a factory with historically a 95% male workforce. The restroom design accounts for this. Can I argue that the male/female gender ratio is different than 50/50?

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Are shower duration controls an acceptable water-saving strategy?

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Can I include process water savings in order to earn an Exemplary Performance point?

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Will the reviewers accept a spreadsheet as a plumbing fixture schedule in lieu of the plans from the Construction Documents?

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Credit achievement rate

XX%

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LEEDuser expert

Carlie Bullock-Jones

Ecoworks Studio
Principal

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USGBC logo

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

Intent

To further increase water efficiency within buildings to reduce the burden on municipal water supply and wastewater systems.

Requirements

Employ strategies that in aggregate use less water than the water use baseline calculated for the building (not including irrigation). The minimum water savings percentage for each point threshold is as follows:

% Reduction Points
30% 2
35% 3
40% 4

Calculate the baseline according to the commercial and/or residential baselines outlined below1. Calculations are based on estimated occupant usage and must include only the following fixtures and fixture fittings (as applicable to the project scope): water closets, urinals, lavatory faucets, showers, kitchen sink faucets and pre-rinse spray valves. [Europe ACP: Water Use Baseline]

Commercial Fixtures, Fittings, and Appliances Current Baseline (Imperial Units) Current Baseline (Metric units)
Commercial Toilets 1.6 gallons per flush (gpf)*
Except blow-out fixtures: 3.5 (gpf)
6 liters per flush (lpf)
Except blow-out fixtures: 13 lpf
Commercial Urinals 1.0 (gpf) 4 lpf
Commercial Lavatory (Restroom) Faucets 2.2 gallons per minute (gpm) at 60 pounds per
square inch (psi), private applications only (hotel
or motel guest rooms, hospital patient rooms)
0.5 (gpm) at 60 (psi)** all others except private
applications
0.25 gallons per cycle for metering faucets
8.5 liters per minute (lpm) at 4 bar (58 psi),
private applications only (hotel or motel guest
rooms, hospital patient rooms)
2.0 lpm at 4 bar (58 psi), all others except
private applications
1 liter per cycle for metering faucets
Showerheads 2.5 (gpm) at 80 (psi) per shower stall **** 9.5 lpm at 5 bar (58 psi)
For projects with commercial pre-rinse spray valves, the flow rate must comply with the asME a112.18.1 standard of 1.6 gpm or less.

Residential fixtures, fittings, and appliances Current baseline (imperial units) Current baseline (metric units)
Residential toilets 1.6 (gpf)*** 6 liters per flush (lpf)
Except blow-out fixtures: 13 lpf
Residential lavatory (bathroom) faucets 2.2 (gpm) at 60 psi 4 lpm
8.5 lpm at 4 bar (58 psi), private applications only
(hotel or motel guest rooms, hospital patient rooms)
2.0 lpm at 4 bar (58 psi), all others except private
applications
1 liter per cycle for metering faucets
Residential kitchen faucet
Residential showerheads 2.5 (gpm) at 80 (psi) per shower stall**** flow rate ≤ 6.1 lpm
(no pressure specified; no performance requirement)
* EPAct1992 standard for toilets applies to both commercial and residential models.
** in addition to Epact requirements, the american society of Mechanical Engineers standard for public lavatory faucets is 0.5 gpm at 60 psi (2.0 lpm at 4 bar (58 psi)) (asME a112.18.1-2005). this maximum has been incorporated into the national uniform plumbing Code and the international plumbing Code.
*** EPAct 1992 standard for toilets applies to both commercial and residential models.
**** residential shower compartment (stall) in dwelling units: the total allowable flow rate from all flowing showerheads at any given time, including rain systems, waterfalls, bodysprays, bodyspas and jets, must be limited to the allowable showerhead flow rate as specified above (2.5 gpm) per shower compartment, where the floor area of the shower compartment is less than 2,500 square inches (1.5 square meters). for each increment of 2,500 square inches (1.5 square meters) of floor area thereafter or part thereof, an additional showerhead with total allowable flow rate from all flowing devices equal to or less than the allowable flow rate as specified above must be allowed. Exception: showers that emit recirculated nonpotable water originating from within the shower compartment while operating are allowed to exceed the maximum as long as the total potable water flow does not exceed the flow rate as specified above.

The following fixtures, fittings and appliances are outside the scope of the water use reduction calculation:

  • Commercial Steam Cookers
  • Commercial Dishwashers
  • Automatic Commercial Ice Makers
  • Commercial (family-sized) Clothes Washers
  • Residential Clothes Washers
  • Standard and Compact Residential Dishwashers

Alternative Compliance Paths (ACPs)

Europe ACP: Water Use Baseline

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

XX%

Upgrade to LEEDuser Premium to see how many projects achieved this credit. Try it free »

Got the gist of WEc3 but not sure how to actually achieve it? LEEDuser gives step-by-step help. Premium members get:

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  • 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.

In LEED review comments I've been referred to the Water Use Reduction Additional Guidance document. I didn't know this was a required reference document.

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.)

Should I include bar sinks? What about mop sinks or janitor sinks? Swimming pools? Safety showers? Bidets? Tub spouts?

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.)

We provided new showers in our project to comply with the alternative transportation credit. Should they be considered in WEp1 calculations?

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.)

Can you explain the 12-second duration for metering faucets?

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.)

Can I use a nonpotable water source to contribute to WEp1 compliance?

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.)

Our project does not have any eligible water fixtures in the project boundary. Can we comply with WEp1?

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.)

We are having trouble finding EPAct-compliant fixtures. Is that a problem?

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.)

Where can I find a clear meaning of "public" and "private" as relevant to lavatory faucets?

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.)

Our project is a factory with historically a 95% male workforce. The restroom design accounts for this. Can I argue that the male/female gender ratio is different than 50/50?

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.)

Are shower duration controls an acceptable water-saving strategy?

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.)

Can I include process water savings in order to earn an Exemplary Performance point?

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.)

Will the reviewers accept a spreadsheet as a plumbing fixture schedule in lieu of the plans from the Construction Documents?

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.)

LEEDuser expert

Carlie Bullock-Jones

Ecoworks Studio
Principal

See all LEEDuser forum discussions about this credit » Subscribe to new discussions about Schools-2009 WEc3