To reduce effects on natural water resources and reduce burdens on community water supply and wastewater systems.
For nonresidential buildings, mixed-use buildings, and multifamily residential buildings four stories or more:
Indoor water usage in new buildings and buildings undergoing major renovations as part of the project must be an average 20% less than in baseline buildings. The baseline usage is based on the requirements of the United States Energy Policy Act of 1992 and subsequent rulings by the Department of Energy, the requirements of the United States Energy Policy Act of 2005, and the fixture performance standards in the 2006 editions of the Uniform Plumbing Code or International Plumbing Code as to fixture performance. Calculations are based on estimated occupant usage and include only the following fixtures and fixture fittings (as applicable to the project scope): water closets (toilets), urinals, lavatory faucets, showers, kitchen sink faucets, and prerinse spray valves.
The water efficiency threshold is calculated as a weighted average of water usage for the buildings constructed as part of the project based on their conditioned area. Projects may also follow the LEED for Multiple Buildings and On-Campus Building Application Guide alternative calculation methodology to show compliance with this prerequisite.
|Commercial fixtures, fittings, or appliances||Baseline water usage|
|Commercial toilet||1.6 gpf1 (6 lpf1)
Except blow-out fixtures, 3.5 gpf (13.2 lpf)
|Commercial urinal||1.0 gpf (4 lpf)|
|Commercial lavatory (restroom) faucet||2.2 gpm at 60 psi (8.5 lpm) at 4 bar ( 58 psi), private applications only (hotel-motel guest rooms, hospital patient rooms)
0.5 gpm at 60 psi2 (2 lpm) at 4 bar (58 psi) all others except private applications
0.25 gallons per cycle for metering faucets (1 liter per cycle)
|Commercial prerinse spray valve (for food service applications)||Flow rate ≤ 1.6 gpm (6 lpm) (no pressure specified; no performance requirement)|
|1 EPAct 1992 standard for toilets applies to both commercial and residential models.
2 In addition to EPAct requirements, the American Society of Mechanical Engineers standard for public lavatory faucets is 0.5 gpm at 60 psi (2 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.
|Residential Fixtures, Fittings, and Appliances||Baseline water usage|
|Residential toilet||1.6 gpf3 (6 lpf3)|
|Residential lavatory (bathroom) faucet||2.2 gpm at 60 psi (8.5 lpm) at 4 bar ( 58 psi)|
|Residential kitchen faucet|
|Residential showerhead||2.5 gpm at 80 psi per shower stall4 (9.5 lpm) at 5.5 bar (80 psi)|
|gpf = gallons per flush; psi = pounds per square inch.
Source: Adapted from information developed and summarized by the U.S. EPA Office of Water.
3 EPAct 1992 standard for toilets applies to both commercial and residential models.
4 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, shall be limited to the allowable showerhead flow rate as specified above (2.5-gpm or 9.5 lpm ) per shower compartment, where the floor area of the shower compartment is less than 2,500 sq.in. (1,600,000 sq. mm). For each increment of 2,500 sq.in. (1,600,000 sq. mm). 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 shall be allowed. Exception: Showers that emit recirculated non-potable 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.
For new single-family residential buildings and new multiunit residential buildings three stories or fewer, 90% of buildings must use a combination of fixtures that would earn 3 points under LEED for Homes 2008 WE Credit 3, Indoor Water Use.
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