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Draft RESNET Water Efficiency Rating Index Technical Guidelines Open for Public Review and Comment


For the past two years a group of water and energy efficiency professionals have been developing the RESNET Water Efficiency Rating (WER) Index.  RESNET is partnering with the International Code Council (ICC) to develop a national consensus standard for a Water Efficiency Rating Index (WER Index). The development of the national standard is co-chaired by:

  • Jacob Atalla of KB Home
  • Ed Osann of the Natural Resources Defense Council
  • Jonah Schein of the U.S. Environmental Protection Agency’s WaterSense program.

The RESNET WER Index will work with water efficiency of a home in the manner that the HERS® Index works for energy efficiency.

The RESNET WER Index is based on the following policies:

  • The WER Index Reference Home tracks with the reference home of the HERS® Index (the water use applications that represent standard new home construction in 2006)
  • Modeling produces a WER Index that will be a quantitative assessment of the relative efficiency of two buildings (reference and rated home) that produces a numeric scale. The reference home will be assigned a WER Index Score of 100. The relative departure of the rated home from the Reference Home will be either added to or subtracted from the 100 score.  The more efficient the rated home, the lower its score.
  • The WER Index score will be based on calculations of potable water use.

The near term goal is to create a water efficiency rating index that the HERS® infrastructure can readily and timely adopt – Vision is that the 165,000 new homes that are rated and issued a HERS® Index annually can also be cost effectively assigned a WER Index score at an affordable cost to builders.

The development of the RESNET WER Index technical guidelines are guided by a WER Index Working Group that is composed of water and energy efficiency professionals.  To see the members of the working group go to WER Index Working Group.

A draft of technical guidelines for the WER Index has been drafted.  The guidelines were developed by the below technical subcommittees:

  • Modeling and Development of Reference Home Technical Subcommittee chaired by Philip Fairey of the Florida Solar Energy Center and Jonah Schein of the EPA WaterSense program.
  • Indoor Water Use Technical Subcommittee chaired by Joe Azzarello of Kohler
  • Outdoor Water Use Technical Subcommittee chaired by Doug Bennett of the Southern Nevada Water Authority

The members of the technical subcommittees are posted at Members of WER Index Task Force Technical Subcommittees.

The proposed WER Index Technical Guidelines are at Proposed WER Index Technical Guidelines

In addition the following supporting information is available:

Prior to going through the formal RESNET ANSI standard development process, RESNET is offering interested persons an opportunity to review and comment on the draft of the proposed guidelines.

Interested parties are encouraged to comment on the proposed technical guidelines.

RESNET is particularly interested in receiving comments on Section 3.0 regarding the presence or absence of automatic outdoor irrigation system.  For a discussion on the issue click here.

RESNET hosted webinar on the draft WER technical guidelines on Wednesday March 15, 2017 at 1:00 p.m.  Click on WER Webinar to view the recording.

Public comments on the proposed amendment will be accepted until May 15, 2017.

To submit your comments click on RESNET WERI Index Technical Guidelines Comment Online Form

Comments are posted real time and you will be able to review comments that were submitted by clicking on Draft RESNET WER Index Technical Guidelines Comments

Only comments made through the online system will be accepted.

After the comment period, the RESNET WER Index Working Group will consider and document its consideration of each of the comments submitted and make appropriate changes. The revised proposed amendments will then be submitted to the RESNET Board of Directors for adoption.