LEED (Leadership in Energy and Environmental Design Certification) Water Efficiency 2 — Questions and Answers
Question 1: Which LEED credit category specifically addresses cooling tower water management?
- Indoor Water Use Reduction
- Outdoor Water Use Reduction
- Cooling Tower Water Management (Correct answer)
- Water Metering
Correct answer: Cooling Tower Water Management
LEED has a dedicated Cooling Tower Water Management credit that targets water efficiency in HVAC cooling systems.
Question 2: What is the baseline flush volume (gpf) for a standard tank-type toilet under LEED Water Efficiency calculations?
- 1.28 gpf
- 1.6 gpf (Correct answer)
- 2.0 gpf
- 3.5 gpf
Correct answer: 1.6 gpf
LEED v4 uses 1.6 gpf as the baseline for tank-type toilets when calculating water use reduction.
Question 3: A building installs a greywater system to flush toilets. Which LEED prerequisite or credit does this strategy primarily support?
- Outdoor Water Use Reduction
- Indoor Water Use Reduction (Correct answer)
- Water Metering
- Rainwater Management
Correct answer: Indoor Water Use Reduction
Using greywater for toilet flushing directly reduces potable water consumption for indoor fixtures, supporting the Indoor Water Use Reduction credit.
Question 4: Under LEED v4, which of the following appliances is NOT typically included in the indoor water use baseline calculation?
- Toilets
- Urinals
- Cooling towers (Correct answer)
- Lavatory faucets
Correct answer: Cooling towers
Cooling towers are addressed in a separate LEED credit (Cooling Tower Water Management) rather than the indoor water use baseline fixtures.
Question 5: What does 'potable water' mean in the context of LEED Water Efficiency credits?
- Water that has been recycled from greywater sources
- Water that meets drinking water quality standards (Correct answer)
- Water collected from rainfall
- Water used exclusively for irrigation
Correct answer: Water that meets drinking water quality standards
Potable water meets drinking water quality standards and is suitable for human consumption; LEED credits aim to reduce its use wherever non-potable alternatives suffice.
Question 6: Which metric is used to measure outdoor irrigation water efficiency in LEED's Outdoor Water Use Reduction credit?
- Evapotranspiration rate (ET)
- Gallons per square foot per year
- Landscape water requirement (LWR) relative to baseline (Correct answer)
- Precipitation index
Correct answer: Landscape water requirement (LWR) relative to baseline
LEED calculates outdoor water reduction by comparing the designed landscape water requirement (LWR) against a calculated baseline using regionally-appropriate species and irrigation efficiency.
Question 7: A project achieves a 50% reduction in outdoor irrigation water use. Under LEED v4 BD+C, what is the minimum percentage reduction required to earn the Outdoor Water Use Reduction credit?
- 25%
- 30% (Correct answer)
- 40%
- 50%
Correct answer: 30%
LEED v4 BD+C requires a minimum 30% reduction in landscape water use compared to the calculated baseline to earn the Outdoor Water Use Reduction credit.
LEED (Leadership in Energy and Environmental Design Certification) Water Efficiency 2
Which LEED credit category specifically addresses cooling tower water management?