New WERS program focuses on water saving building design
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The HERS score has become the standard for energy efficiency in homes, and now the WERS score will do the same for water usage.
WERS, or Water Efficiency Rating Score, is a performance-based approach to residential water efficiency that takes into account both indoor and outdoor water usage.
WERS got its start with the Green Builder Coalition which, 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), created water modeling software that generates a Water Efficiency Rating Score, or WERS.
A formal committee, consisting of representatives from BGNM, the SFWCC, the SFAHBA, The Coalition, the Santa Fe Community College (SFCC), and other national stakeholders continues to refine the award-winning 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 “structural waste.”
Structural waste is the amount of water that is typically wasted before usable hot water arrives at the furthest hot water using fixture. The calculation for structural waste was based on the water wasted for conventional water heating systems.
How it Works
Extensive research was done to calculate the loading from the main plumbing fixtures, clothes washers and structural waste 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," said 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 periodically 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."
The program continues to be developed under the tutelage of several industry stakeholders and is being piloted by 14 licensees in 10 states. Now that the WERS is available, new legislation sponsored by Senator Peter Wirth has been passed by the New Mexico legislature and signed by the Governor. The intent is to add water efficiency to the existing Sustainable Building Tax Credit legislation, which already incorporates energy efficiency. The City of Santa Fe has passed a resolution calling for the addition of the WERS to its residential green building codes. The Santa Fe Sustainable Commission recently honored the WERS program with a Sustainable Santa Fe Award in the “Water Adaptation” category. Additionally, The Coalition is working with Santa Fe Community College to develop a training program for use of the WERS program, verification procedures, and certification.
As it gathers the final feedback on the pilot version, 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’ve also formed a national committee to help us with the next iteration of the WERS program, where we’ll look to expand the outdoor portion.”
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