HERS Rater writing on notebook.

HERS Rater vs. Building Inspector

Contrary to popular belief, the average home inspection does not include detailed testing of HVAC systems. While basic functioning is checked, furnaces, heat pumps, air conditioners and other HVAC systems can still function with major malfunctions. Your home inspection generally is not detailed enough to give you the full picture of how your heating and cooling systems are performing. After all, your HVAC is the most important system in your home, and you want to make sure it’s working properly, up to building code, and energy efficient. 


Many homeowners not familiar with HERS Testing often ask why they need both a building inspector and a HERS Rater. While both are inspectors of California regulations, what they are testing is different. In fact, home inspection reports come with multiple disclaimers about their lack of HVAC knowledge. Additionally, in many stated (including California), there are no license requirements for home inspectors. 

  • HERS Rater
    • Tests for energy efficiency
    • Checks for air leakage, improper insulation and the proper HVAC appliances are installed
    • HERS Testing is REQUIRED when an HVAC system is installed, replaced, relocated or when building an addition
  • Building Inspector
    • Inspects the “building code” to make ensure the buildings structure is in intact
    • Checks for health & safety issues regarding the home’s envelope
    • REQUIRED when there is major reconstruction or construction to the home
    • Often a good idea when purchasing a home

 When to call a HERS Rater

After completion of a HVAC installation or relocation, the HERS Rater must perform the verification and testing. This step is required prior to calling for a final inspection from the building inspector.  

When to call the Building Inspector

The last step once installation is completed is the final inspection. Inspectors check that everything is up to code and operational, including airflow at the registers, operational equipment, and flue gas venting terminations. They also audit for energy code compliance and depressurization.

Need help with the HERS process? Have questions? Click Find A Pro and you’ll see a list of HERS Raters in your area.