To meet this prerequisite, teams must assess the efficiency of the installed indoor plumbing fixtures, including lavatory faucets, toilets, urinals, kitchen sinks, and showerheads. They must determine how much potable water is consumed relative to a LEED baseline case.

Perform the calculation using a calculator developed by USGBC. Teams should become very familiar with the calculator, the information needed to complete it, and the various rules for using it in order to accurately assess performance.

Alternatively, teams have the option to meter fixtures and fittings and record metered water use data for one year to establish a baseline. The USGBC calculator is not used under this option.

All projects, regardless of which compliance option is pursued, must develop a fixture and fitting replacement and retrofit policy. USGBC has developed a template policy to help teams with this requirement.

What’s New in LEED v4

• USGBC added metered water use as a second option for prerequisite compliance.
• Teams can no longer apply nonpotable water in the prerequisite calculation.
• Under the calculated water use option, the baseline multiplier date has changed from 1994 to 1995. Additionally, the multiplier for pre-1995 water use has changed from 160% of UPC/IPC plumbing codes to 150%. The multiplier for post-1995 water use remains the same at 120% of UPC/IPC.
• Duration-based savings from autocontrol faucets with sensors or metering controls are no longer allowed, since studies have shown that autocontrol faucets do not produce water savings.

Readiness Review Questions

• How many different types of each fixture are installed in the building? Are fixture specs or product data sheets available for the installed fixtures?
• Do you have the staff resources to survey installed fixtures if an accurate inventory doesn’t already exist?
• Was the building initially occupied before or after 1995? This will determine your water use baseline. If occupancy was pre-1995, were any plumbing renovations completed during or after 1995 (thereby impacting the baseline for those specific fixtures)?
• Are there any high-intensity water uses? For example, is there a fitness center with showers?
• What opportunities exist for low-cost upgrades? 

• What upgrades will have the greatest effect on reducing water consumption? 

• Are rebates or incentives available to offset upgrade costs?
• Are fixtures and fittings separately metered? Can metered data be provided for a full year?