Home Energy Rating Score (HERS)

HERS testing is especially useful for finding hidden problems, sometimes in combination with use of thermal imaging, such as disconnected ducts inside inaccessible areas such as wall cavities, where ducts run up/down between floors of a building. 

The Home Energy Rating System (HERS) 

The Home Energy Rating System (HERS) checks new and remodeled homes for energy efficiency. A Home Energy Rating is a measurement of a home’s energy efficiency. In the United States, the Residential Energy Services Network (RESNET) is responsible for creation and maintenance of the RESNET Mortgage Industry National Home Energy Rating Standards, as well as certification and quality assurance on RESNET Provider organizations.

Home energy ratings can be used for either existing homes or new homes. A home energy rating of an existing home allows a homeowner to receive a report listing options for upgrading a home’s energy efficiency. The homeowners may then use the report to determine the most effective ways in which to upgrade the home’s energy efficiency. A home energy rating of a new home allows buyers to compare the energy efficiency of homes they are considering buying.

The rating scores homes from 0 to 150. The lower the score, the better the energy efficiency of the home.

How the HERS Score Works

RESNET trains and licenses HERS raters to examine new homes and newly renovated homes for energy efficiency.

After inspecting the home and running the data through specialized software, the rater assigns a HERS score on a scale of 0 to 150. The lower the number, the better the score. Each one-point change in a score, up or down, represents a one percent shift in energy efficiency.

To get an accurate score the rater compares the home to a standard Reference Home. The Reference Home isn’t an actual house, just an analysis tool, but it resembles the rated home as much as possible—same size, shape, environment, and climate. This means the score is relative to the type of house, in a specific climate zone.

The US Department of Energy (DOE), the Department of Housing and Urban Development (HUD), and the Environmental Protection Agency (EPA) recognize the HERS Index as an official verification of home energy performance. 

HERS testing is required in California. In California, most times it is done at the time the house is originally built, or when a new heater and air-conditioning gets installed.  Then the building department will force the contractor to provide HERS rating to guarantee the work is done right and the ducts are airtight. 

HERS testing is especially useful for finding hidden problems, sometimes in combination with use of thermal imaging, such as disconnected ducts inside inaccessible areas such as wall cavities, where ducts run up/down between floors of a building. 

See how climate zones are defined

Help Your Clients Prepare for Better Ratings

A home is a system. As a home inspector you understand how all the points you check during a home inspection add up to a sound, safe, and usable system for living. You can help your clients achieve a low energy saving score by detecting failures in systems that increase energy usage.

Home energy raters check for system places in the home where energy use may increase through faulty or inefficient systems in the home. A better score provides immediate cost savings to your client, improves the home’s sale value, and is also an indicator of mortgage repayment reliability. 

As a home inspector you can help your clients prepare for a better energy score by identifying systems that need improvement. Indicating places for system improvements, allowing a home owner to begin remediation and repairs to help conserve energy.

Some of the top concerns for raters, fall under the scope of a standard home inspection. 

  • Air leaks in the building envelope
  • Heating, ventilating, and air conditioning (HVAC) distribution duct leaks
  • Any combustion risks
  • Air infiltration rate 

Air leaks are the most common faults that raise a HERS score. Inspectors can incorporate thermal imaging to help identify these air flow leaks.  

As you perform your inspection, you identify system faults and leaks in the home system. 

  • Wall and ceiling insulation
  • Water heating systems
  • Thermostats
  • Foundations
  • Attics and crawl spaces

When you follow the ASHI Standards of Practice your inspection identifies any areas where systems can be improved. From faulty air ducts to insufficient insulation, your experienced eye recognizes systems that need improvement. 

Inspection Report to the Rescue

Your report alerts clients to system calls that need remediation. As a legal document, your report serves to educate your client. They can show your findings to anyone they contract for repairs. 

When you call out major concerns, you help your client understand how repairs will improve the energy efficiency of the home. 

Don’t be shy about spelling it out in the report. Findings are a guide to improving the home.

Distribution Ducts – Monitor, Major Concern:  Disconnected heating & cooling supply air ducts were noted at the attic crawlspace . It is recommended a licensed HVAC contractor be contacted to further investigate this condition.

Insulation – Repair:  Missing/damaged floor insulation was noted at the sub-area crawlspace (under the kitchen, family room, and nook). 

Central Air Conditioning – Monitor, Major Concern:  Pet urine damage and corrosion was noted at the central air conditioning system condenser compressor unit. It is recommended a licensed HVAC contractor be contacted to further investigate this condition.

Help clients understand how air flow, leaky windows, poorly sealed doors, and other sources of energy loss can increase their energy bill. 

As always, client awareness is part of our ongoing education. 

A New Revenue Source for Inspectors

As an inspector, you may want to add being a Home Energy Rater. The Home Energy Rating industry is overseen by RESNET and is structured to ensure a high level of quality assurance. With that in mind, energy raters must work through a Rating Provider, who is responsible for their certification and quality assurance.

The responsibilities and requirements to be an accredited rating provider are defined in Chapter One of the Mortgage Industry National Home Energy Rating Standards

Find certified training through RESNET. After a course of study, you must pass a core competency test. Finally, sign a rater agreement with a RESNET accredited Rating Provider and complete probationary ratings. You must complete all training and testing requirements within 15 months. 

You can then offer your service to local builders, or to people getting their heating or air-conditioning replaced. 

HERS Benefits the Market

Low HERS scores are fantastic for a home’s resale value. Homes with low HERS scores and good energy efficiency can command a higher price—up to 30 percent higher than similar, less efficient homes.

Home buyers may initially pay more for a home with a low score, but long-term they will save paying consistently lower energy bills. 

The Home Energy Rating Score is getting phased in. Currently in California It’s required for new homes, so 30 years later all homes will be energy-efficient. But energy efficiency is becoming a standard in more and more states. 

Published in the American Society of Home Inspectors ASHI Reporter, October 2020 issue.


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