LEED Indoor Water Use Reduction
Baseline against design water use for toilets, urinals, faucets and showerheads, the percentage reduction, the 20% prerequisite and the credit points.
The LEED v4 and v4.1 BD+C calculation for the Indoor Water Use Reduction prerequisite and credit. The daily uses each occupant type makes of each fixture (Reference Guide Tables 8 and 9) are multiplied by the flush volume, or by the flow rate and the default duration, once at the Table 1 baseline and once with the fixtures you specify. The prerequisite needs a 20% reduction and WaterSense or equivalent labelling; the credit awards 1 point at 25% up to 6 at 50% for New Construction, and up to 5 at 45% for Schools, Retail, Hospitality and Healthcare.
Occupants and operation
Residents from the building
Hotel: rooms × 1.5 × 60%. Multifamily: bedrooms + 1 per unit.
Fixtures specified (design case)
Reduction against the LEED thresholds
Annual water by fixture
Baseline Design
Fixture by fixture
| Fixture | Daily use | Baseline rate | Design rate | Baseline a year | Design a year | Saving | Reduction |
|---|
Uses per day by occupant type
| Occupants | Number | Water closet | Urinal | Public lavatory | Private lavatory | Kitchen | Shower |
|---|
Export
Questions engineers ask
What does the calculator compare?
The annual water of the fixtures you specify against the same building fitted at the LEED baseline: 6 L (1.6 gal) per flush for toilets, 3.8 L (1.0 gal) for urinals, 1.9 L/min (0.5 gpm) for public lavatory faucets, 8.3 L/min (2.2 gpm) for private lavatory and kitchen faucets and 9.5 L/min (2.5 gpm) for showerheads. The uses per occupant and the durations are the Reference Guide defaults.
How many points can the credit earn?
New Construction: 25% gives 1 point, then one more for each 5% up to 6 points at 50%. Schools, Retail, Hospitality and Healthcare: the same steps up to 5 points at 45%. Below 20% the prerequisite is not met and the project cannot certify.
How are dual-flush toilets and metering faucets counted?
A dual-flush toilet is taken at one full and two reduced flushes. A metering faucet rated per cycle is converted to a flow rate (volume per cycle × 60 ÷ cycle seconds) and used with the default 30 seconds; sensors and timers earn no duration savings in the design case.
What if some restrooms have no urinals?
Set the share of male users who have urinals available. The urinal uses of the rest are counted at the water closet, in the baseline and the design alike, as the USGBC calculator does.
Does it apply to LEED v5?
No. LEED v5 replaced this fixture calculation with its whole-project water use framework. For a v5 project use the LEED scorecard on this site for the points, and this page for a fixture-level check.
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