In January, the American National Standards Institute approved the fourth version of the National Green Building Standard ICC-700 as an American National Standard. Now, builders and developers have a choice to seek NGBS Green certification based on either the 2015 NGBS or the 2020 NGBS. Which is the best version for your project and your market?

Some may presume that compliance with the 2015 NGBS would be less challenging and/or less expensive to achieve. However, the 2020 NGBS Consensus Committee has made several important improvements that warrant strong consideration before embarking on your next green building project.

NGBS Green is designed to be a voluntary, above-code program. So, one factor to consider is which building code version is in effect where you’re building. Typically, the biggest difference between the code minimum requirements and what’s required in the NGBS deals mostly with energy efficiency. Since energy efficiency improvements tend to add the most cost to a project, this is a logical place to start your analysis. Buildings located in states that are on the 2009 IECC may want to consider the 2015 NGBS as a starting point. However, buildings in states that have already adopted the 2018 suite of I-codes will definitely want to consider the 2020 NGBS.

When comparing energy efficiency requirements in the 2015 vs. 2020 NGBS, a home or low-rise multifamily building located in a state at the 2009 IECC has to be approximately 23% more energy efficient than a code-minimum home to earn 2015 NGBS Green certification at the Bronze level; the same project needs to be approximately an additional 2% more efficient to earn 2020 NGBS Green certification at the same level. With such a small incremental increase in efficiency, going for 2020 NGBS Green certification may make the most sense if it’s attainable within the project budget.

But a green home is not built on energy efficiency alone. The 2020 NGBS has a number of new practices that earn points toward certification, including those that promote car- and bike-sharing, bike storage, areas with high intersection density, and on-site recreation space.

The 2020 NGBS also includes voluntary practices that reward above-code resilient design practices, and acknowledges the importance of being able to age in place as an important component of sustainability. While the 2015 NGBS included some of these practices, builders using the 2020 NGBS can gain additional recognition for going “above and beyond” in these categories and others by attaining NGBS Green+ badges.

The 2020 NGBS also offers a streamlined Certified path for higher-volume home builders that eliminates certification point counting by providing a single list of mandatory green practices. Compliant homes, townhouses, and duplexes will achieve an energy efficiency level roughly equivalent to the Silver certification level and must successfully incorporate a series of practices, equipment, and systems focused on the most impactful green measures, such as moisture management, durability, water efficiency, and improved indoor quality.

Home Innovation has created an NGBS version decision tree to help you select the best NGBS option for your project. The decision tree and the other resources mentioned here can be found online at