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Green Building Curmudgeon

The National Green Building Standard Turns 20(20)

Navigating the ANSI process to update and broaden the use of a key green building certification program

The National Green Building Standard, AKA NGBS Green, is a residential green building certification program that has continued to grow in popularity.  Also known as ICC-700, it has been revised twice since the now-retired 2008 version was released.

Currently, the 2015 version is available for use throughout the U.S., and the 2012 version is available for registration through December 2019 in 22 states that have not yet adopted the 2012 or later IECC.  The program is managed by Home Innovation Research Labs, previously known as the NAHB Research Center, a well-respected building science and standards organization.

Being an ANSI standard, it requires periodic updating, and the next version is nearing the end of this process.  Originally intended to be called the 2018 version, due to the work involved, it is currently scheduled to be released as the 2020 version.

Making sausage

For each revision cycle, a diverse group of experts, knows as the Consensus Committee (CC), meets over a several years to develop the updated standard, review public comments, and vote on a final version.  Working along with the CC are Task Groups, consisting of CC members and other industry experts, that assist in resolving the details of the standard.

If it sounds like sausage making, trust me: it very much is.  Anyone who is interested can follow the process by reading posted documents at the Home Innovation web site, and are welcome to volunteer for committees and task groups for the next iteration when the process starts again.  Reading the documents can be an excellent cure for insomnia, and attending meetings can inspire one to learn patience and restraint.

For the 2020 version, I served as a member of two task groups, contributed comments to others, and attended several meetings of the CC to observe and comment on the process.   The last CC group meeting was held February 11 to 13, 2019, in Washington, DC, and it ended with a reasonably complete standard ready for a final round of public comments and a vote for adoption sometime during the spring of 2019.

Aiming to increase market share

While NGBS has had significant impact in the multifamily market, particularly in affordable housing, it has struggled, as have most green programs, with adoption by builders of single-family homes.  Most builders and program verifiers believe this is due to the complexity of the program, consisting of a detailed Excel workbook, a 202-page standard, hundreds of mandatory items and optional measures, and over 1100 points to choose from to complete the certification process.

A small group of participants worked on developing an alternative path to certification that limits options and streamlines the process through a simple prescriptive list of requirements.  At the most recent meeting, the Consensus Committee overwhelmingly voted in the affirmative to adopt the alternative certification path, against much resistance from several participants, particularly the U.S. Environmental Protection Agency (EPA).

Less rigorous?

Following approval of the new path, an EPA representative confronted myself and others, insisting that the new path was a disaster,  and threatened to personally ruin the entire program through the media, based on their conviction that it was less rigorous than the current  program and created a dangerous precedent.  Conversely, proponents of the new prescriptive certification path believe that it is overall equally as rigorous as Bronze level certification, meets Silver lever or higher in Energy and Water Efficiency, and by simplifying the process, expect NGBS Green to capture a larger share of the single-family market. The final decision will be rendered after additional balloting and public comment process.

Other changes to the standard allow for projects that include as much as 49% non-residential space to be certified; allowing for live-work projects to meet the 2020 standard; for commercial space within multifamily buildings to be certified — these areas are not able to be certified in current versions — and for the expansion of the definition of dwelling units to include sleeping units, thereby allowing for certification of dorms, assisted living facilities, hotels, and similar projects.

The future

The most current version of NGBS (the 2015 version) will be the only one available for use for projects registered after December 31, 2019.  The next version is expected to be available for certification in 2020, with the 2015 remaining available for use until a sunset date is determined, after which it may no longer be used for certification.

A group of verifiers, affiliated professionals, and Home Innovation staff worked diligently to shepherd the new NGBS version through the ANSI development process.  Our sincere hope is that the new certification options available will allow the program to grow, particularly in the single-family market.


  1. Expert Member
    CARL SEVILLE | | #1

    For anyone interested, public comment period is now open for the final draft. Details here:

  2. mmaccy | | #2

    Hi Carl - Wondering if you have any feedback on the 2020 standard now that it's being implemented. Thank you!

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