Analytics Comes to Water Systems

Efficiency rating for water systems growing in use.

By Mike Collignon

The use of analytics, modeling, and metrics is seemingly increasing in nearly everything, whether it’s in advertising, sports, or social media.

Now they’ve made their way into the construction industry. In the energy efficiency world, there is the Home Energy Rating System (HERS) and the U.S. Department of Energy’s Home Energy Score (HES). Water efficiency even has a performance-based metric too: the Water Efficiency Rating Score, or WERS.

What Is WERS?

WERS is a predictive, performance-based approach to residential water efficiency and water resource management. The WERS is the culmination of calculations considering the loading from principal plumbing fixtures, clothes washers, structural waste, and outdoor water management. Potential rainwater, greywater, stormwater, and blackwater catchment are also calculated.

The WERS program is applicable for both new and existing single-family and multi-family residential properties. It uses a scoring scale of 0-100 with zero being the most desirable and 100 representing the baseline home. In addition to the score, the property owner receives daily, monthly, and yearly projections of water usage.

Teams building a project also have the ability to use the WERS design tool to view initial estimates of the results of their proposed installed fixtures and appliances, as well as innovative water conservation strategies without the involvement of a WERS verifier.

In order to obtain a WERS, the project team sends the completed program document to a qualified third-party WERS verifier who then checks that fixtures, appliances, and strategies have been installed or implemented as claimed. Once the program document has been verified, it is then sent to the Green Builder® Coalition for certification processing.

The certification document issued can then be used by the project team for anything from compliance with a water conservation tax credit or incentive to a local building code that requires third-party verification.

How Is WERS Being Used?

Unlike a prescriptive program, a performance-based program gives all parties (architect/designer, builder, property owner) design and product flexibility. It doesn’t require anything. Rather, it assesses the choices made. The same flexibility extends to the implementation of the WERS program.

On its own, the WERS program can help a property owner understand where and how water is being used. Without this knowledge, it’s difficult to determine the most cost-effective conservation strategies.

For those who use wells, the combination of the projections and deeper insight into their system’s capabilities can help manage overall water usage. This can prove helpful when faced with extended dry spells.

But a voluntary modeling tool is just one way to use the WERS program. It can also be adopted as a regulation. The city of Santa Fe, New Mexico, is nearing the finish line on the road to becoming the first municipality in the nation to integrate a performance-based water efficiency requirement in its residential green building code. Santa Fe County is strongly considering using WERS in a regulatory manner if a project meets certain conditions.

The state of New Mexico allows a builder or new property owner to attach a WERS report to show compliance with the new water efficiency requirement of the state’s popular Sustainable Building Tax Credit. The WERS program has joined Build Green New Mexico and LEED for Homes as compliance paths for water.

The GreenHome Institute (GHI) after months of discussion, scrutiny, and testing began the process of implementing the WERS program as the water criteria for GreenStar, its residential green building program available nationwide. Projects achieving certain WERS levels will obtain a majority of their water points for various certification levels.

“Home energy scores and models are now becoming the norm. Why not water next?” asks Brett Little, GHI’s executive director. “It just makes sense. You can’t manage what you don’t measure and you easily weed out most waste through informed design.”

Growing Support

In addition to the entities mentioned above, the WERS program has received promotional support from the National Ground Water Association and the American Rainwater Catchment Systems Association.

Meanwhile, the WERS–Manufacturer Program currently has two members, Evolve Technologies and EcoVie Environmental. Both manufacturers are offering discounts on specific products deployed on projects pursuing WERS certification. By the end of 2016, the number of manufacturers is expected to double.

The WERS program will have been a part of 15 educational sessions at national or regional conferences, including NGWA Groundwater Week 2016, since the beginning of 2015.

Speaking of educational events, Santa Fe will host the inaugural Next Generation Water Summit on June 4-6, 2017. This first-of-its-kind national event will feature three educational tracks, two keynote speakers, and an expo. The event’s tracks will focus on emerging policy development, building design and construction, and water conservation tools and technologies. For information, visit www.NextGenerationWaterSummit.com.


Mike Collignon is the executive director and co-founder of the Green Builder Coalition. He can be reached at info@greenbuildercoalition.org.