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RESNET Board of Directors Adopts RESNET Water Efficiency Rating Technical Guidelines

Mar 15, 2018

Water is the new frontier for RESNET and HERS® Raters. In many parts of the nation water is fast becoming an ever increasingly expensive commodity. Other parts of the country are experiencing droughts.  There is clearly a need for a system that can mirror the HERS® Index to rate a home’s efficiency in water use. This will allow homebuyers to know how efficiently water is being used in the homes they are considering to buy. It will also provide an opportunity for homebuilders to monetize the efficiency of their homes in the same fashion that the HERS® Index plays for energy efficiency.  By tying it with the HERS® Index, it will also allow the rapid deployment of the water efficiency rating system through the network of over 1,900 certified RESNET HERS® Raters and hundreds of builders that have their homes HERS® rated.

In 2014 the RESNET Board authorized the development of a RESNET water efficiency rating system.  The RESNET water efficiency rating system is called RESNET HERSH2O®  ©.

On February 23, 2018, the RESNET Board of Directors adopted the RESNET HERSH2O®
Technical Guidelines.  The guidelines will serve as the technical basis for RESNET’s water efficiency rating system, HERSH2O®.  The guidelines were developed over a period of more than two years and included a public review and comment process.

The guidelines can be downloaded at RESNET HERSH2O®. Technical Guildelines.

To develop the HERSH2O®technical guidelines, RESNET formed a working group to oversee the development of the program’s technical guidelines.  The working group was 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

Members of the working group are:

•    Dave Bell, TopBuild Home Services
•    Peter V. DeMarco, International Association of Plumbing and Mechanical Officials
•    Philip Fairey, Florida Solar Energy Center
•    Gary Kline, Gary Kline and Associates
•    Brent Mecham, Irrigation Association
•    Kathy Nguyen, Cobb County, Georgia Water System
•    Thomas E. Pape, Best Management Partners
•    Kim Shanahan, Santa Fe Area Homebuilders Association
•    Kent Sovocool, Southern Nevada Water Authority
•    David Wells, International Code Council

The draft of the HERSH2O® technical guidelines were developed by five technical subcommittees:

•    Modeling and Development of Reference Home
•    Indoor Water Appliances
•    Outdoor Water Use
•    Rating Inspection and Testing Procedures
•    Rater Training and Qualification Requirements

The RESNET HERSH2O® Technical Guidelines are being field tested by the national production builders KB Home and Meritage Homes in the states of:

•    Arizona
•    California
•    Colorado
•    Florida
•    Nevada
•    Texas

The guidelines were featured in an open house demonstration of a KB Home that was HERSH2O® rated at the 2018 RESNET Building Performance Conference in Orlando.


RESNET HERSH2O® Open House –  From left to right:  Jonah Schein, EPA; Jacob Atalla, KB Home; Steve Baden, RESNET; Dave Wall, ICC; Mark Johnson, ICC; Dave Bell, TopBuild; Ed Osann, NRDC.

RESNET is partnering with the International Code Council (ICC) to develop an ANSI national consensus standard for rating the water efficiency rating of a home, the Water Rating Index.  To develop the ANSI candidate standard a joint RESNET/ICC Standard Development Committee (SDC) 1100 was formed.  The members of the SDC 100 are:

•    Jacob Atalla, KB Homes – Chairman
•    Jonah Schein, EPA WaterSense – Vice Chairman
•    Brett Cook, Building Code Official, City of Boardman, Oregon
•    Mary Ann Dickinson, Executive Director, Alliance for Water Efficiency
•    Andrew Espinoza, Building Code Official, City of San Antonio, Texas
•    Philip Fairey, Deputy Director, Florida Solar Energy Center
•    Ed Osann, Team Leader – Water Use Efficiency, Natural Resources Defense Council
•    David Sauter, Building Code Official, Hatfield Township, Pennsylvania
•    Kelly Stephens, Director of Operations, SunRiver Development

The SDC 1100 held its first meeting in conjunction with the 2018 RESNET Building Performance Conference.

The initial Water Rating Index standard will be based on the RESNET HERSH2O® technical guidelines.

It is expected that the draft Water Rating Index standard will be released soon for public review and comment.