Water Performance: Water Efficiency Credit for LEED Existing building (O+M)
Water is a valuable resource that must be preserved and managed efficiently, especially in buildings. The Leadership in Energy and Environmental Design (LEED) program developed by the U.S. Green Building Council (USGBC) includes a Water Performance prerequisite for existing buildings (O+M) and interiors. The intent of this prerequisite is to support water management and reduce water consumption. The following article will explain the requirements and steps to obtain LEED points for water performance.
The requirements for complying with the Water Efficiency Credit for LEED Existing Building (O+M) include having installed water meters that measure total potable water use for the project and grounds, as well as collecting monthly data for 12 consecutive months. The minimum water performance score required is 40, with additional points awarded for higher scores according to Table 1. Interiors projects without fixtures or fittings in the project scope are exempt from the minimum score requirement but must still input data and calculate a score.
| Water Performance Score | LEED Points |
|---|---|
| 40 (Required) | 6 (Required) |
| 44 | 7 |
| 50 | 8 |
| 57 | 9 |
| 64 | 10 |
| 70 | 11 |
| 77 | 12 |
| 84 | 13 |
| 90 | 14 |
| 97 | 15 |
Step-by-Step approach to comply the credit:
Step 1: Check Meters: Ensure that all water meters installed in the project building and grounds are functioning correctly to capture water usage. Include all water usage for irrigation, indoor plumbing fixtures, domestic hot water, process water, reclaimed water, boiler water, and cooling towers. For interior projects, ensure that sub-meters are included in the project scope or establish a process for pro-rating water usage based on occupancy and base building water use.
Step 2: Measure Water Use: Collect the total potable water use for 12 consecutive months, which equals one full year.
Step 3: Input Data: Input your building’s water consumption using one of the following methods:
- Upload USGBC data import spreadsheet
- Share water data from ENERGY STAR Portfolio Manager
- Connect existing BAS or meters to the platform (contact USGBC for more information)
- Enter data manually
You can enter data for any project-defined intervals, and make sure there are no gaps or missing data, and all meters for all water sources are included. Also, input your weighted occupancy and weighted operating hours using the USGBC calculator.
Step 4: Determine Water Performance Score: After entering the data, the platform will produce a water performance score for your project.
Step 5: Prepare Documentation for Certification Review: Complete the prerequisite information, including the following documentation:
- Utility bills for all water sources, with consumption values and dates highlighted
- Calculated water performance score. A minimum performance score of 40/100 is required.