Profile
Approximately 41% of potable water use in a typical office building in the U.S. can be attributed to plumbing fixtures (Figure 3).4 Additionally, office buildings account for approximately 9% of the total water use in commercial building in the US, and of this, 22% is attributed to irrigation and landscape maintenance.5 Management of water used for operation of plumbing fixtures and irrigation can typically address the majority of overall water consumption.
Considerations
Understanding both indoor and outdoor water usage is essential to water conservation. Sites should begin the water use examination process by determining how water is being used. Water audits provide intelligence on how to prioritize water strategies. In addition to monitoring overall water use, sites should install submeters on irrigation, wells, WWT systems, and cooling tower make-up water.
Figure 3: Typical U.S. office building potable water use, 2017
Data Source: EPA
The most effective sequence for pursuing water efficiency is:
- Load reduction: Making operational improvements on existing water systems can provide instant benefits. The systems’ base load can be significantly impacted by occupant behavior, leaks, fixture efficiencies, and irrigation schedules that do not account for outdoor weather conditions.
- System efficiency: Retrofitting plumbing fixtures and irrigation systems, such as with high-efficiency or dual-flush toilets, aerators, low-flow showerheads, and drip irrigation, can lead to significant water savings.
- Renewable resources: Many water end uses can be served by non-potable or renewable water sources, including rainwater or reclaimed wastewater. These systems can make a significant impact on sites that are not connected to fully developed municipal supply or treatment systems.