WHAT IS A HERS RATING?

A Home Energy Rating Service (HERS) Rating is a comparative analysis of how energy efficient your home is compared to other similar homes.

The rating will demonstrate how energy efficient the rated home is, whether new or existing. In relation to a RESNET / HERS reference home that is built to International Energy Conservation Code (IECC), 2006 minimum requirements. The energy efficiency of the rated home will be represented by a variable HERS index. The HERS reference home is a “geometric twin” of the rated home, and is built to the thermal standards and energy efficiency standards required by the IECC 2006; and always has a HERS index of 100.

For example, If the HERS index of your new or existing home is 125, It is projected to use 25% more energy than a similar home that is built to the minimum energy code of 2006. Alternately, If the HERS index of your new or existing home is 75, it is projected to use 25% less energy than a similar home that is built to the minimum energy code of 2006.

AN ENERGY RATING REQUIRES:

    • In the case of a “to be built” home: The rating requires:

      • a construction plans review and software modeling in an approved software program.

      • at least 2 site visits, and diagnostic building envelope and duct system testing, during construction and after completion.

    • In the case of an existing home: The rating requires:

      • an onsite inspection of the home as is, and software modeling in an approved software program, stating the as is / as found HERS index.

      • a presentation of proposed cost effective weatherization improvement measures to the client, stating the projected post improvement HERS index after proposed measures are installed.


    • In the case of an Energy Efficient Mortgage product: The rating requires:

      • an onsite inspection of the home as is, and software modeling in an approved software program, stating the as is / as found HERS index.

      • a presentation of proposed cost effective weatherization improvement measures to the client, stating the projected post improvement HERS index after proposed measures are installed effectively.

      • at least 1 additional site visit and diagnostic building envelope testing, after selected measures are complete to verify the wxn measures installed are effective. The difference in the as found HERS index and the post improvement HERS index demonstrates the level of energy efficiency improvement that was conducted and can show the cost effectiveness of the improvements. The cost effectiveness can be presented to the mortgagee for preferred financing terms.



If you’re building to the ENERGY STAR® Version 3 certification, the house being built will be compared to the ENERGY STAR® reference home, which is compared to the 2006 IECC.


If you’re not building to the ENERGY STAR® Version 3 certification, but want the energy performance characteristics documented for mortgage or marketing reasons, a HERS rating will provide that documentation, including HERS index. 

At Horizon RES NH LLC, all HERS activities including modeling, inspecting and testing will be conducted by a nationally recognized RESNET certified Home Energy Rater, working under the HERS  providership umbrella of Horizon RES NH LLC.