What is Water Use Intensity (WUI)?
If you benchmark water use in Portfolio Manager, one of the key metrics you'll see is water use intensity, or WUI. Essentially, the WUI expresses a building's water use as a function of its size or other characteristics. For most property types in Portfolio Manager, the WUI is expressed as gallons per square foot per year. It's calculated by dividing the total water consumed by the building in one year by the total gross floor area of the building.
Percentile Breakdown of WUIs in the United States
In addition to the median, the 5th, 25th, 75th, and 95th percentile values have been provided in the table below for further context. Where possible, median values for property-type-specific metrics (operating characteristics specific to each property type) have also been included.
For details on how these national water use intensities are calculated, see Portfolio Manager Technical Reference: U.S. Water Use Intensity by Property Type.
| Portfolio Manager Property Type | WUI (gal/ft²/year) Percentile | ||||
|---|---|---|---|---|---|
| 5th | 25th | 50th/Median | 75th | 95th | |
| College/University | 2.48 | 6.20 | 13.40 | 28.34 | 66.92 |
| Fire Station | 5.00 | 13.95 | 28.90 | 54.29 | 162.95 |
| Hospital (General Medical & Surgical) | 14.30 | 38.28 | 55.71 | 77.44 | 151.18 |
| Hotel | 23.94 | 40.06 | 52.02 | 69.28 | 120.23 |
| K-12 School (includes Pre-school/Daycare) | 3.04 | 6.88 | 10.84 | 19.71 | 55.69 |
| Medical Offices (includes Urgent Care/Clinic/Other Outpatient) | 5.73 | 12.86 | 23.40 | 38.82 | 84.71 |
| Multifamily | 16.76 | 31.71 | 45.15 | 65.56 | 126.14 |
| Non-Refrigerated Warehouse (includes Self-Storage Facility and Distribution Center) | 1.15 | 1.84 | 3.43 | 6.69 | 20.88 |
| Office (includes Bank Branch/Financial Office/Other Offices) | 2.93 | 7.83 | 14.48 | 29.41 | 81.52 |
| Retail Store | 1.41 | 2.84 | 5.24 | 8.99 | 28.59 |
| Senior Living Community | 22.18 | 39.80 | 56.41 | 77.69 | 129.26 |
| Supermarket (includes Grocery Store, Wholesale Club and Supercenter) | 9.65 | 21.03 | 31.00 | 45.58 | 78.42 |
Understanding the Reference Data
The ENERGY STAR program has been able to provide similar Energy Use Intensity (EUI) data by property type primarily using data from the U.S. Energy Information Administration's Commercial Building Energy Consumption Survey (CBECS). Since no comparable data source exists for water use in buildings, ENERGY STAR and WaterSense prepared this document using information entered by users in the ENERGY STAR Portfolio Manager benchmarking tool for calendar year 2019 (except for multifamily buildings, which use a different data source).
The data in ENERGY STAR Portfolio Manager is entered by individual account holders voluntarily or, in some cases, as required by a local or state law. None of the water benchmarking data entered into Portfolio Manager by users is verified by EPA. As a result, while efforts have been taken to eliminate clearly erroneous data, property types that are highly skewed in terms of climate/geographic region, and property types that lack a variety of operators, the data should not be interpreted as being statistically representative.
Adding Property Types
EPA will evaluate data again in the future and work to add property types as more data becomes available in Portfolio Manager. In addition, EPA offers the 1-100 Water Score for multifamily properties. The score evaluates a multifamily building relative to its peers, similar to ENERGY STAR scores, and also adjusts for climate and business activity. Learn more about the 1-100 Water Score for multifamily properties. EPA will also continue to evaluate the possibility of adding Water Scores as data becomes available to support this.