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What is the Difference Between a HERS Rater, an RFI, and a Residential Energy Auditor?

First of all, the term 'HERS' stands for 'Home Energy Rating Systems' and a certified HERS Rater is a residential energy efficiency professional that understands building science, heating & cooling equipment, residential building construction, clean energy systems, ventilation & filtration and much more. A Rating Field Inspector or 'RFI' performs the energy tests and inspections required for a residential energy rating on behalf of their affiliated certified HERS Rater. An energy auditor also tests and inspects residences for energy efficiency but has limitations that raters do not have.

Here are Some Example Programs Authorized for Certified HERS Raters but not for Energy Auditors:

  • Approve Energy Efficiency and Renewable Energy Tax Credits and Incentives;
  • Provide testing and verification services for energy code compliance inspections;
  • Approve and certify residences under national energy efficiency programs;
  • Approve and certify residences under national green/sustainable programs;
  • Qualify homes to receive benefits through lucrative energy mortgage programs: (See video below)


I am new to this industry – do you have a recommended training/certification/work path for me to follow?

Congratulations on choosing to become involved with energy and green!  There is a lot to learn and even those of us who have been working in this field for over four decades are still learning new things every single day.  The recommended path below will help you gain expertise one step at a time.

  • RESNET Certified Rating Field Inspector (RFI) – preparing for this certification will provide the RFI Candidate training on energy usage in a home, creating scaled sketches, gathering energy usage data in the field, proper use of infiltration and duct leakage testing equipment and understanding of basic residential construction techniques and materials. The RFI Candidate must take and pass the Combustion Appliance Zone simulation test.  A Rating Field Inspector works under a Certified HERS Rater who is responsible to complete the RFI’s certification by overseeing their performance in the field while they gather data for three Home Energy Ratings.  Information on recommended RFI Training courses can be found here.
  • RESNET Certified Energy Modeler - This class teaches the data points that must be gathered and input into Rating software to generate an accurate energy model.  It includes reading plans, calculating building dimensions, energy modeling of the structural components, mechanical systems and equipment, on-site energy generation, on-site test results, lighting, appliances, and other building information.  It provides information about the accredited energy modeling software tools and generating and interpreting HERS Rating reports.  This is a brand-new certification designation. Learn more about the energy modeler certification and course here.
  • RESNET Certified HERS Rater – this class will add training on heat load calculations, reading and working with building plans, proper use of certified software, climate zones, advanced construction techniques, thermal bypass and insulation installation inspections and reporting.  To complete certification, two simulated ratings, one simulated combustion appliance zone safety testing session, and one rigorous written exam must be taken and passed and five probationary ratings must be satisfactorily performed within one year as an internship with a Quality Assurance Provider.  Learn more about becoming a HERS Rater here.
  • Where you go from here is up to you. There are advanced HERS Rater training and certification classes available, you may choose to become a Green Rater, to qualify to certify homes for national green programs, to include infrared inspections in your offerings, etc.  There are also advanced designations focusing on ENERGY STAR verification, HVAC system commissioning verification, and more.

Learn more about the difference between a HERS Rater and Energy Auditor here.