Can you do a HERS Rating on an apartment in a 30-story building? Not now, but maybe in 2019!

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.

ANSI/RESNET/ICC 301-2014On 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. Read more

Technically Speaking: Not All Insulation is Graded Equally

About a year ago, I worked along with other HERS raters and the North American Insulation Manufacturers Association (NAIMA, a.k.a. Insulation Institute) to conduct a study on the importance of insulation installation quality and grading.

RESNET, the nation’s leading home energy efficiency network and the governing body of the Home Energy Rating System (HERS® Index) established standards for grading insulation installation.

The grading is as follows:

Grade I— the best and nearly perfect install which includes almost no gaps or compression… what some would call “G.O.A.T.”
Grade II—allows for up to 2% of missing insulation (gaps) and up to 10% compression over the insulation surface area… what some would call “mad decent”.
Grade III—insulation gaps exceed 2% and compression exceeds 10%… anything worse and the insulated surface area is considered un-insulated.

RESNET Insulation Diagram

Source: RESNET Mortgage Industry National HERS Standards

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CT Zero Energy Challenge (Part 1) – How Low Can You Go?

There were 11 projects entered into this year’s CT Zero Energy Challenge, sponsored by EnergizeCT.  The single- and multi-family homes taking part in this competition are designed and constructed utilizing innovative techniques in order to try and reach the illustrious goal of net-zero energy-use.

I’m excited to report that SWA worked with 4 of the homes entered into this year’s competition, including the first- and third-place winners! For each of the three winning projects, EnergizeCT has created a video to showcase the story behind the homes, and to highlight some of the most notable features.

Today’s video is about the first-place winner, a single-family home in South Glastonbury, CT, constructed by Glastonbury Housesmith. The owners, Carl Benker and Elizabeth Wegner are first-time homebuyers who wanted to be able to live as close to “off the grid” as possible. Check out SWA’s HERS-rater extraordinaire, Karla Donnelly, discussing the competition, and how this home came to achieve an amazing HERS Index Rating of a -23!

(Right-click and select “run this plug-in” if you cannot see the video below)


The project also won the 2015 RESNET Cross Border Challenge for lowest HERS score with photovoltaics (PV)!

You can read more information on SWA’s project here.