How to Pick an NGBS Certification Path Based on 2020 Remodeling Updates

Green-building buffs rejoice: The National Association of Home Builders has announced that the new 2020 updates to the National Green Building Standard (NGBS) program offer remodelers more flexibility in project certification.

The ICC 700-2020 NGBS now allows remodelers to get their projects certified by using a prescriptive path. The new option awards a project points “based on a suite of practices offered to improve energy and water efficiency,” according to NAHB. 

Before, remodelers could only gain project certification through a performance path, which grants certification based on a percentage reduction in energy and water consumption compared to in the conditions of the pre-renovated building. 

More flexibility for green certification

For even more flexibility, remodelers can mix and match which paths they use to gain certification. They can use a prescriptive path for meeting both energy and water standards, a performance path for both, or one for energy and one for water. 

Because the existing housing stock is diverse, the new changes will offer more flexibility to achieve energy- and water-efficient designs that are the best match for a location’s market conditions, regulatory requirements, and climate zone best practices, according to Michelle Diller, the program manager for sustainability and green building at NAHB.

“Providing more options to achieve a green remodel is important as no one size fits all,” Diller says. “The addition of prescriptive compliance paths for remodelers, and the flexibility to mix and match those paths for energy and water in the same project provides additional opportunities for all types of housing to have a cost-effective green retrofit.”

New for 2020: A prescriptive path for remodelers

Prescriptive paths will allow remodelers to gain points for efficient upgrades or building practices such as efficient fixtures, appliances, structural plumbing, irrigation practices, and the use of innovative practices including water capture and reuse, according to NAHB. The number of points earned for selected practices determines the certification level achieved.

Carl Seville, NAHB member and partner at SK Collaborative in Atlanta, Ga., says that including the prescriptive path helps remodelers certify homes that may already have efficient upgrades that would prohibit them from scoring high through the performance path based on how the score is calculated through the NGBS worksheet. 

“If a home already has high efficiency plumbing fixtures, it can be difficult, if not impossible to show the required improvement for the Performance Path,” Seville says. “The Prescriptive Path assigns points to each plumbing fixture and appliance based on their efficiency, allowing a project to meet certification regardless of the existing conditions.”

Additionally, the prescriptive path streamlines the certification process by eliminating the performance path’s need for an analysis of conditions before and after the remodel to confirm that the project can meet the minimum efficiency improvements to certify. “If a project is able to obtain enough points through the prescriptive path to certify, it could eliminate the cost of preparing the ratings, saving both time and money,” Seville says. 

Here are the certification thresholds for prescriptive paths: 

When to go with a performance path

A performance path could be the way to go if following a local code or regulation would result in a significant percentage improvement compared to the existing conditions.

For example, Diller says a high-efficiency plumbing upgrade may result in large reduction of water usage compared to an outdated fixture, and that percentage reduction may qualify the project for a higher level of certification than the prescriptive path for the water efficiency category.

Location can also come into play, according to Diller. If a remodeler’s project in an area of the country--think of hot Southwestern deserts--where outdoor water use is a substantial portion of the total water use, updating the outdoor landscaping to include efficient irrigation and drought-tolerant landscaping could also bump up the rating. 

Here are the certification thresholds for performance paths:

Remodelers can certify both whole-home renovations and small projects, though small projects follow their own prescriptive path for certification. Find out more information about NGBS at Home Innovation Research Labs.