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RESNET - Learn about the HERS rating index and the Green Addendum

Click here to visit the
official RESNET website

Click here to review 2017 HERS  Ratings by State.  How did your state do?

RESNET, Setting the Nation's Standards for Home Energy Efficiency

The Residential Energy Services Network (RESNET) was founded in 1995 as an independent, non-profit organization to help homeowners reduce the cost of their utility bills by making their homes more energy efficient.

How Does the HERS Index Work?

To calculate a home’s HERS Index Score, a certified RESNET Home Energy Rater will do a home energy rating and compare the data against a 'reference home' – a design modeled home of the same size and shape as the actual home, so the HERS Index Score is always relative to the size, shape and type of house you live in. The lower the number, the more energy efficient the home.

A typical resale home represents 130 on the HERS Index while reference home (a standard new home built in 2006) is rated at 100.

  • A home with a HERS Index Score of 70 is 30% more energy efficient than a standard new home.
  • A home with a HERS Index Score of 130 is 30% less energy efficient than a standard new home.

RESNET Podcast by self proclaimed
‘Green Queen’ – Sandra Adomatis

RESTalk EP9: "Energy Efficiency Has Value When You Can Measure It, Market It, And Sell For It!, the latest RESNET podcast by Sandra Adomtis fresh off her presentation at the 2018 Appraisal Institute Conference.  Sandra talks about the importance of the partnership between RESNET and the Appraisal Institute to launch a new online Appraisal Portal, to help residential appraisers compare the value of energy efficient homes. 

Sandra Adomatis of Adomatis Appraisal Service is making it her mission to answer that question by helping the US real estate industry appreciate that you need to measure it, market it, and sell for it.

Click here to listen to this podcast


Developed by the Residential Energy Services Network and introduced in 2006, the HERS Index is the industry standard by which a home's energy efficiency is measured. Government agencies such as the Department of Energy (DOE), Department of Housing and Urban Development (HUD) and the Environmental Protection Agency (EPA) recognize the HERS Index as an official verification of energy performance.


Click here to view a video on the basics of the HERS Rating Index

Click here for a 2019 Update on the Growing Demand for HERS Ratings


The Residential Green and Energy Efficient Addendum (pdf form)

The objective of this Addendum is to standardize the communication of the high performing features of residential properties.  Identifying the features not found on the appraisal form provides a basis for comparable selection and analysis of the features.  

Builders, contractors, homeowners, and third party verifiers are encouraged to complete this Addendum and present to appraisers, agents, lenders, and homeowners.  Appraisers typically do not have sufficient information to complete this addendum without builder, contractor, or third party verifier documentation.  

Attach this completed document to the MLS listing to provide sufficient detail on sales and listings to assist buyers, appraisers, and real estate agents in understanding the high performance features of the property.

Complete the pages that apply to the property appraised and provide to appraiser prior to the completion of an appraisal.  

Provide the Addendum to the lender at the time of loan application to assist them in understanding the property type so an appraiser with sufficient knowledge of this property type will be engaged to provide an appraisal to meet secondary mortgage market guidelines.

Click here to access the Green Addendum form (pdf)

Click here to find additional resources in the valuation of green properties and completion of the Green Addendum form


Residential Green Valuation Tools.

Residential Green Valuation Tools explores the six features that make a home green—proper siting, water and energy efficiency, indoor air quality, materials, and operations and maintenance—and provides:

    - A comprehensive overview of the valuation of high-performance homes
    - Case studies illustrating common scenarios and valuation problems
    - Detailed instructions on how to complete the AI Residential Green and Energy Efficient Addendum form
    - Tips for appraising Energy Star homes, passive solar houses, solar photovoltaic systems, and net-zero energy homes

Appraisers who value green homes are breaking new ground and face unique challenges. Residential Green Valuation Tools provides the methods and resources you need to meet these challenges and become a green-friendly appraiser.

A textbook resource for completing the AI Residential Green and Energy Efficient Addendum is available. 
Click here to purchase

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