Home >Articles >State of Vermont Adopts Modified 2015 International Energy Conservation Code HERS Index Score Option to Its State Building Energy Code

State of Vermont Adopts Modified 2015 International Energy Conservation Code HERS Index Score Option to Its State Building Energy Code

Mar 19, 2015

On March 1, 2015, a modification to the Vermont state building energy code, the Vermont Residential Building Energy Standard (RBES), went into effect.  The code modification includes an Energy Rating Index option.  The Vermont RBES applies to all new residential construction, including additions, alterations, renovations, and repairs.

Section R 406 of the RBES contains the Energy Rating Index Compliance Alternative option for code compliance.  The Energy Rating Index option to the Vermont energy code is based on the 2015 International Energy Conservation Code (IECC) Energy Rating Index option with two significant changes.

Vermont’s action represents the first state that has adopted the 2015 IECC Energy Rating Index compliance option.

For minimum code the State of Vermont adopted the following HERS Index Scores:

Base Code Target 60 Maximum HERS Index to demonstrate code compliance
Sub Target 65 Maximum HERS Index without any renewable incorporated
Renewables Addition Limit 5 Maximum HERS Index Points that can be counted towards code target

The Vermont code includes an aspiration and innovative path called the Vermont Stretch Code that local municipalities can adopt as a leadership standard.  The Vermont Stretch Code requires the following HERS Index Scores:

Stretch Code Target 54 Maximum HERS Index to demonstrate code compliance
Sub Target 65 Maximum HERS Index without any renewable incorporated
Renewables Addition Limit 11 Maximum HERS Index Points that can be counted towards code target

To view the amended Vermont standard go to Vermont Residential Building Energy Standard

The IECC is a national model code.  States and local jurisdictions are allowed to alter the model code provisions to meet local conditions. While state and local jurisdictions may alter the Energy Rating Index scores, it is RESNET’s policy to support the Energy Rating Index compliance option adopted in Section R 406 of the 2015 IECC.

RESNET has published a set of factsheets on the Energy Rating Index option of the 2015 IECC.  They cover:

To educate code officials, home builders and HERS Raters on the Energy Rating Index compliance option, RESNET has produced a series of PowerPoint presentations. The presentations are targeted for:

  • HERS Raters
  • Builders
  • Energy efficiency code advocates

The presentations can be downloaded at The HERS Index as a Performance Path to Building Energy Codes