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| v3 - LEED 2009

Water use reduction

WEp1 | Required

Intent

To increase water efficiency within the tenant space to reduce the burden on municipal water

Requirements

Employ strategies that in aggregate use 20% less water than the water use baseline calculated for the tenant space (not including irrigation).

Calculate the baseline according to the commercial and/or residential baselines outlined below. Calculations are based on estimated occupant usage and must include only the following fixtures and fixture fittings located within the tenant space: water closets, urinals, lavatory faucets, showers, kitchen sink faucets and prerinse spray valves.

Commercial Fixtures, Fittings, and Appliances Current Baseline (Imperial Units) Current Baseline (Metric Units)
Commercial toilets 1.6 gallons per flush (gpf)*
Except blow-out fixtures: 3.5 (gpf)
6 liters per flush (lpf)
Except blow-out fixtures: 13.5 lpf
Commercial urinals 1.0 (gpf) 4.0 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
Commercial prerinse spray valves
(for food service applications)
Flow rate ≤ 1.6 (gpm)
(no pressure specified; no performance requirement)
Flow rate ≤ 6 lpm (no pressure specified; no performance requirement)

Residential Fixtures, Fittings, and Appliances Current Baseline (Imperial Units) Current Baseline (Metric Units)
Residential toilets 1.6 (gpf)*** 6 liters per flush (lpf)
Residential lavatory (bathroom) faucets 2.2 (gpm) at 60 psi 8.5 lpm at 4 bar (58 psi)
Residential kitchen faucet
Residential showerheads 2.5 (gpm) at 80 (psi) per shower stall**** 9.5 lpm  at 5.5 bar (80 psi) per shower stall
 
*       EPAct 1992 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/9.5 lpm) 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
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