TheLEED for Homes Rating System (v4)addresses landscape water use in theWater Efficiency (WE) Credit: Outdoor Water Use, which requires calculating the design landscape water requirements to optimize irrigation efficiency. Key factors influence the water needs of a landscape, guiding the design and irrigation strategy.
According to theLEED Reference Guide for Homes Design and Construction (v4):
WE Credit: Outdoor Water Use (1–4 points)
Calculate the landscape water requirement based on the following factors:
Vegetation selection: Choose plants with low water needs (e.g., native or drought-tolerant species).
Microclimate: Consider site-specific conditions like sun exposure, shade, and wind that affect evapotranspiration rates.
Irrigation type: Select efficient systems (e.g., drip irrigation) to minimize water waste.These factors are used to estimate the water demand and design an efficient irrigation system.Source: LEED Reference Guide for Homes Design and Construction, v4, Water Efficiency Credit: Outdoor Water Use, p. 98.
TheLEED v4.1 Residential BD+Crating system confirms:
WE Credit: Outdoor Water Use
The design landscape water requirement is determined by vegetation selection, microclimate factors (e.g., sun/shade), and irrigation system efficiency (e.g., drip vs. spray).
Source: LEED v4.1 Residential BD+C, Credit Library, accessed via USGBC LEED Online.
The correct answer isvegetation selection, microclimate, and irrigation type(Option B), as these are the primary factors for calculating water requirements per LEED guidelines.
Why not the other options?
[Reference: LEED Reference Guide for Homes Design and Construction, v4, WE Credit: Outdoor Water Use, p. 99 (discusses implementation, not calculation factors)., C. Soil slope, “no-disturbance” zones, and runoff velocity: These relate toSustainable Sitescredits (e.g., Rainwater Management) for managing runoff, not calculating landscape water needs.Reference: LEED Reference Guide for Homes Design and Construction, v4, Sustainable Sites Credit: Rainwater Management, p. 76., D. Soil pH, soil compaction, and impervious surfaces: While soil conditions affect plant health, they are secondary to vegetation, microclimate, and irrigation for water requirement calculations. Impervious surfaces are relevant to heat island or runoff credits.Reference: LEED Reference Guide for Homes Design and Construction, v4, WE Credit: Outdoor Water Use, p. 98., TheLEED AP Homes Candidate Handbookemphasizes WE credits, including outdoor water use, and references theLEED Reference Guide for Homes Design and Constructionas a key resource. The exam is based onLEED v4, ensuring the relevance of these factors., References:, LEED Reference Guide for Homes Design and Construction, v4, USGBC, Water Efficiency Credit: Outdoor Water Use, p. 98–99., LEED v4.1 Residential BD+C, USGBC LEED Credit Library, accessed via LEED Online (https://www.usgbc.org/credits)., LEED AP Homes Candidate Handbook, GBCI, October 2024, p. 12 (references study resources and exam scope based on LEED v4)., USGBC LEED for Homes Rating System (v4), available via USGBC website (https://www.usgbc.org/resources/leed-homes-design-and-construction-v4)., LEED v4.1 for Homes, USGBC, accessed via LEED Online, confirming landscape water factors., ]
