A New Focus on Water: New Mexico’s Water Efficiency Rating Score (WERS)

This is a press release from Mike Collignon, Executive Director and Co-Founder, Green Builder Coalition. As Executive Director and Co-Founder of the Green Builder® Coalition, Mike engages in national and state-level advocacy, co-produces quarterly research reports, and publishes both a bi-monthly e-newsletter and a monthly feature in Green Builder® Magazine.

The Green Builder® Coalition, in cooperation with Build Green New Mexico (BGNM), Santa Fe Area Home Builders Association (SFAHBA), and members of the City of Santa Fe Water Conservation Committee (SFWCC) has created water modeling software that generates a Water Efficiency Rating Score, or WERS.

The initial goal was to integrate the WERS into the BGNM program and use it to document an empirical method of calculating eligibility for water use reduction tax credits. In February of 2014, goals were generated along with an initial action plan. In the following months, a formalized committee, consisting of representatives from BGNM, the SFWCC, the SFAHBA, The Coalition, and the Santa Fe Community College (SFCC), continued to refine the WERS program.

Measurable parameters were established as the foundation of WERS, along with a scoring scale of zero to 100 with zero being the most desirable. The decided focus was on indoor water use that involved the main plumbing fixtures of toilets, showers, lavatories, kitchen sinks, clothes washers and “pipe priming”. Pipe priming is the amount of water that is typically wasted before usable hot water arrives at the furthest hot water using fixture. The calculation for pipe priming was based on the water wasted for conventional water heating systems.

How it Works

Much research was done to calculate the loading from the main plumbing fixtures, clothes washers and pipe priming and their eventual impact on the WERS. For the pilot version, only the indoor water use is calculated empirically based on the estimated loading of the above items while taking into account their associated efficiencies. Rainwater and greywater catchment are also calculated. Depending on the verified filtration methods, they can be used to offset indoor water use much like solar panels can be used to offset energy use in the HERS index. Additionally, any remaining unused rainwater or greywater can be credited to potential outdoor use (if needed) as an innovative practice.

Other aspects of the WERS program include points for “Innovative Practices”. BGNM and SFWCC have both created similar lists of items that can be incorporated into a future version of the WERS calculation process. But, because these items are either not measurable or a method of empirical data collection has not been determined at the launch of the WERS pilot, they are not a part of the final score. It is envisioned that communities will select a minimum point threshold of Innovative Practices that need to be accomplished as part of the WERS program.

“The zero to 100 scale of the WERS program plays right into the competitive nature of builders and the marketplace,“ says Kim Shanahan, Executive Officer of the SFAHBA. ”Consumers can easily assess the most water efficient home. A performance-based metric always produces better results than a purely prescriptive standard. It drives innovation and best practices that are quickly adopted by others.”

Project teams have the ability to do initial estimates of the results of their proposed installed fixtures and appliances as well as innovative water conservation strategies. In order to actually achieve a WERS, the project team will have to send the completed program document to a qualified third-party verifier who will then check 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 Coalition for certification processing. The certification document that is issued will then be utilized by the project team to apply for any applicable water conservation tax credits or incentives that require third-party verification.

The Market Effect and Relevance

Most product manufacturers of fixtures and appliances that utilize water are already well aware of the multitude of green home building programs, as well as the EPA WaterSense program. Many have responded well by providing products that easily comply with both the green homebuilding programs and the EPA WaterSense program. As the WERS continues to develop nationally and incorporates items that for now are only considered innovative practices, manufacturers may want to consider following news regarding the program. One of the best ways this can be achieved is by signing up for the Green Builder® Coalition’s communications. There will also be information added soon to the official WERS website, www.wers.us.

“Having a ‘performance path’ for water will help transform the building industry in the same way that the HERS index did for energy”, says Steve Hale, Program Director for BGNM. ”Already, we are seeing much better performing fixtures and appliances. Now, with the ability to ‘mix and match’ flow rates while simultaneously examining the overall performance of indoor water use, builders and consumers can make smart choices for the products they put into their homes.”

Next Steps

The program continues to be developed under the tutelage of several industry stakeholders and has already been piloted within the State of New Mexico. Now that the WERS is available, new legislation sponsored by Senator Peter Wirth has been proposed and will be introduced in the New Mexico Senate legislature this year. The intent is to add water efficiency to the existing Sustainable Building Tax Credit legislation that already incorporates energy efficiency. The City of Santa Fe is also contemplating adding the WERS to its residential building codes. Additionally, The Coalition is working with Santa Fe Community College to begin a training program for use of the WERS program, verification procedures, and certification.

Now that the pilot version is complete, The Coalition is seeking input from other municipalities that are interested in evaluating and potentially using this tool. “We’re very proud of the inaugural version of WERS,” said Green Builder® Coalition Executive Director Mike Collignon. “Now that we’ve completed that work, we’re interested in collaborating with other municipalities who have a need or interest in conserving water. The WERS program can be valuable to those communities as either an incentive or regulation. We’re also forming a national committee to help us with the next iteration of the WERS program, where we’ll look to expand the outdoor portion.”


About Green Builder® Coalition

The Green Builder® Coalition is a not-for-profit association dedicated to amplifying the voice of green builders and professionals to drive advocacy, information and education for more sustainable home building practices. We are an action-oriented community of green builders and professionals dedicated to uniting and growing our joint expertise, values and voice to create stronger standards for sustainable, more environmentally responsible home building. For more information, visit www.greenbuildercoalition.org.

About Build Green New Mexico

Build Green NM is an education and certification program for building High Performance Homes across the State of New Mexico. High performance means added comfort, lower utility bills and healthier indoor air quality to name a few of the key features. We don’t build great homes; we certify them from experienced builders across the state. Added in 2015 is a complementary program regarding efficiency upgrades to existing homes. For more information, please visit www.BuildGreenNM.com.

About Santa Fe Area Home Builders Association

As a local Home Builders Association in one of America’s most progressive and green-focused communities, SFAHBA proudly reflects its local demographic and constantly pushes the envelope in re-imagining the built environment. With national lab scientists, world-renowned artists, and indigenous cultures going back centuries and millennia, Santa Fe builders have many sources of inspiration to draw upon. Their creative thinking on water, energy, and resource efficiency finds its way into the unique homes that embody “Santa Fe Style”. For more information, visit www.sfahba.com.


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Image courtesy Wikimedia