Certified Water Rating Index (WRI) Score

The 2020 NGBS introduced the Water Rating Index (WRI) as a new optional path for newly-constructed homes to demonstrate compliance with water efficiency criteria. A WRI score is a value between 0-100 and can be used to understand the operational costs of a given property. A WRI score indicates a property’s total indoor and outdoor water use compared to a baseline based on the home’s size and basic configurations.

Just like with the Home Energy Rating System (HERS) and the Energy Rating Index (ERI), a lower score demonstrates higher efficiency. A WRI score of 70 or below can be used to comply with either New Construction or Single-Family Certified paths under the 2020 NGBS.

Builder can be on the cutting edge when they take advantage of this new opportunity to set their homes apart from other green certified homes. Builder benefits include:

• Ability to use new terminology to communicate expected water use
• Ability to leverage an additional third-party label as part of their marketing purposes
• Access to new tools that can help them consider various design choices and their impact on water use and expected NGBS points
• Opportunity to pursue the NGBS Green+ ZERO WATER badge

To take advantage of this new opportunity, builders must select a 2020 NGBS accredited verifier who also holds the WRI Verifier credential. These individuals have undergone additional training related to water efficiency and have access to the calculator tools necessary to score and verify a home’s WRI value.

Homes that earn a WRI of 64 or less may be eligible to earn EPA’s WaterSense home label. Builders can leverage EPA’s recognizable symbol for water efficiency and offer assurance that the homes are at least 30% more efficient than typical construction.