Water-use reduction is a good opportunity for all projects to earn points. For this credit you will need to reduce your project’s water consumption from indoor fixtures including: water closets, urinals, lavatory faucets, showers, and kitchen sinks. Other water using appliances and irrigation are not included.

Your baseline for determining percent reduction is based on the Energy Policy Act of 1992 fixture requirements.  You will earn one point for WEc3.1, a 20% indoor water use reduction and a total of two points for WEc3.2, a 30% reduction. You are also eligible for an Exemplary Performance point via IDc1 for a 40% reduction. The calculations for Exemplary Performance can include process water reductions in the total, as long as the EPAct 1992 regulated fixtures first meet a 30% reduction.  

The credits are fairly easy to achieve with careful fixture selection. You also have the option of replacing potable water with non-potable sources—for example using captured rainwater or graywater.

Solutions are simple and widely available

If you pay close attention to the flow rates of the water fixtures you select (gallons per minute for flow fixtures and gallons per flush for flush fixtures), you should be able to achieve a 30% reduction in water use by using widely available efficient fixtures—at a minimal cost premium and without compromising on comfort. 

Some typical approaches here include low-flow faucets with sensors, low-flush or dual-flush toilets, and low-flush or waterless urinals. Use of graywater and rainwater for toilet flushing is also a fairly common way to contribute to the credit.

Combining several of these strategies can bring your water savings within the 30%–40% range, maxing out your points for this credit. 

Try it—you’ll like it

When water-efficient fixtures first appeared in the 1990s, they often didn’t perform very well, creating a lot of doubts that still may be harbored by some project team members. Research and development as well as new testing protocols have really changed things since then, so make sure these doubts are put to rest. Providing hands-on experience with efficient fixtures through visiting another LEED building is a good way to do this. 

Follow these key steps

• Set goals for interior water-use reduction. 
• Determine full time equivalent (FTE) occupancy and fixture usage groups. 
• Create a baseline water budget for indoor water use. 
• Choose fixtures and water reduction or reuse strategies. 
• Estimate the project’s water usage by creating a design case water budget. 
• Use the LEED Online submittal template to compare baseline and design-case water budgets to determine the water reduction percentage for the project. 
• Complete the LEED Online submittal template.

 Consider these questions when approaching this credit

• What occupancy patterns are expected? 
• What are the highest-intensity water uses? How can you target these for savings?
• Is rainwater collection feasible on your site? What are potential sources of graywater for your project? Does the municipality or local water utility supply reused water through a purple pipe? 
• Are rebates or incentives for water-efficient fixtures available in your area?