Party Walls

ANSI/RESNET/ICC 301-2014 is the Standard for the Calculation and Labeling of the Energy Performance of Low-Rise Residential Buildings using an Energy Rating Index. It is the basis of the most common Energy Rating Index, RESNET’s HERS Index, which is utilized by utilities and building programs like LEED^© and ENERGY STAR®, which require a consistent index to evaluate performance.

On March 2, 2018, RESNET released a draft of the 2019 version of ANSI/RESNET/ICC 301, where the most significant change will be the expansion of its scope to include Dwelling Units and Sleeping Units in ANY height building, whether that building is defined by IECC as “Residential” or “Commercial”. Other changes will include those developed by the RESNET Multifamily Sub-Committee, to better address shared systems like HVAC, hot water, solar PV, and laundry, and other scenarios specific to multifamily buildings that have largely been unaddressed until now.  The 1st preliminary draft standard of the 2019 version (dubbed PDS-01) includes these important improvements, along with all addenda to Standard ANSI/RESNET/ICC 301-2014 that were approved prior to March 2.

How Does the Revision Process Work?

The ANSI/RESNET/ICC Standards 301 (and 380) are under “continuous maintenance”. What does this mean? As revisions are needed to improve the standards, they are accomplished via “addenda”. Each addenda has to go through a “public comment” period to ensure that all stakeholders get to provide their opinions or objections to the proposed change before it becomes part of the standard. Rather than re-publishing a new edition of the standard each time a revision is approved, these standards are instead updated every 3 to 5 years to integrate any approved addenda into the body of the standard (instead of as separate addenda), along with any other necessary revisions into a new edition. This is similar to other standards like IECC, ASHRAE 62.2, or ASHRAE 90.1, which typically release a new version every 3 years.

Why Should People Care?

Let’s cut to the chase. As noted above, the updates to ANSI/RESNET/ICC 301-2014 will provide various benefits to the HERS program nationwide. Here are a few from a big picture perspective:

1. This standard is how everyone has been calculating the HERS index for homes and apartments (for utility incentives, ENERGY STAR, LEED, etc.) and was developed for single family and then stretched to MF (with no technical changes to really work for MF). This version will actually make technical changes to better address MF.
2. The new changes will expand the scope so that there is no cap at 3, 4 or 5 stories, as is now. This is a pretty big deal, considering it opens the market for HERS Raters to provide services to taller buildings.

How Do I Get Involved?

A webinar will be held on March 20, 2018 to review the proposed changes and answer your questions. It is highly recommended that you attend this webinar prior to submitting public comment. To register for this webinar, click here.  If you cannot attend the webinar, click here to view the slides from a presentation on the proposed changes to 301-2014 from the RESNET conference.

The public comment period will be open for 45 days beginning March 2, 2018 and ending April 16, 2018. To review and comment on Draft PDS-01, click here. Keep in mind, for a comment to be considered for the next draft (PDS-02), you must propose the SPECIFIC change that you are seeking, using strike-through and underline formatting to show your suggested deletions and insertions. RESNET anticipates a few rounds of public comment, but is hopeful that all issues can be addressed and the new edition of ANSI/RESNET/ICC 301 will be published in early 2019 and available for use later that year.

By Gayathri Vijayakumar, Principal Mechanical Engineer