“Maximizing Water Efficiency in Commercial Buildings: Understanding LEED BD+C Water Efficiency Credits”
The Water Efficiency category of LEED BD+C aims to promote water conservation in commercial buildings. A total of 11 points can be earned under this category. The category includes five credits, namely Outdoor Water Use Reduction, Indoor Water Use Reduction, Building-Level Water Metering, Cooling Tower Water Use, and Water Metering.
Under the Outdoor Water Use Reduction credit, projects can earn required points and an additional 2 points by reducing outdoor water use by 50% and 100%, respectively. For the Indoor Water Use Reduction credit, projects can earn required points plus up to 6 additional points by reducing indoor water use by 20-50%.
Building-Level Water Metering is a mandatory credit that requires installing water meters for all major uses in the building. The Cooling Tower Water Use credit allows projects to earn 2 points by reducing the water use of cooling towers by at least 50%. Lastly, the Water Metering credit requires the installation of water meters for major uses in the building, such as potable water, flush water, and any other water uses.
To earn the credits, specific documentation requirements should be fulfilled. For instance, projects should submit a detailed water use analysis, plumbing fixtures schedule, and flushometer valve specification for the Indoor Water Use Reduction credit. A flow diagram and meter schedule should be submitted for the Building-Level Water Metering credit. For Cooling Tower Water Use credit, projects should provide a summary of the water use calculation and cooling tower water makeup and bleed-off data.
Location can be a constraint for projects to achieve all points under this category. For instance, in areas with limited water supply or high water stress, it may not be possible to achieve the full points for Outdoor Water Use Reduction or Cooling Tower Water Use credits. Projects can explore alternative solutions or consult with the USGBC to find suitable strategies to meet the credit requirements.
A summary table of the Water Efficiency category and its credits is provided below:
|Max Points Achievable
|Outdoor Water Use Reduction
|Water use analysis
|Indoor Water Use Reduction
|Plumbing fixtures schedule
|Flushometer valve spec
|Building-Level Water Metering
|Cooling Tower Water Use
|Water use calculation
|Cooling tower makeup data
|Water meter installation