HERS and Title 24

For some residential projects one or more HERS verifications might be required. A HERS verification is an inspection and/or diagnostic testing performed by a special third-party inspector called a Home Energy Rating System (HERS) rater. HERS verifications are required when using the "prescriptive" package approach to residential Title 24 compliance, but not required when using the "performance" approach. However, HERS verifications can optionally be used in conjunction with the performance approach to achieve extra compliance credit. This can be helpful if, for example, a proposed residence has an unusually large amount of glass and no overhangs. HERS verifications are sometimes used with the performance approach when a residential project needs to exceed the Title 24 baseline standard by 15% or more. If HERS verifications are required they will be listed on the CF-1R compliance form. Nearly all projects that comply using the performance approach do not require any HERS verifications.


A HERS rater is certified to perform the field verification and diagnostic testing that may be required to demonstrate and document compliance with the energy standards. HERS raters receive special training in diagnostic techniques and building science as part of the HERS rater certification process administered by the HERS provider. HERS raters are considered special inspectors by enforcement agencies and shall demonstrate competence, to the satisfaction of the enforcement agency, to conduct the required visual inspections and diagnostic testing of the regulated energy efficiency features installed in the dwelling. HERS raters cannot be employees of the builder or contractor whose work they are verifying. Also, HERS raters cannot have financial interest in the builder’s or contractor’s business, or advocate or recommend the use of any product or service that they are verifying.


Following is a complete list of all Title 24 HERS residential energy efficiency measures. One or more of these field verifications or diagnostic tests may be required in order to meet prescriptive package requirements or receive performance compliance credit. If any of these measures are required they will be listed on the CF-1R compliance form.


  • Duct Sealing and Leakage Testing
  • Supply Duct Location, Surface Area and R-Value
  • Low Leakage Ducts in Conditioned Space
  • Low Leakage Air Handlers
  • Refrigerant Charge in Split System Air Conditioners and Heat Pumps
  • Refrigerant Charge Indicator Display (CID)
  • Verified Cooling Coil Airflow
  • Air Handler Fan Watt Draw
  • High Energy Efficiency Ratio (EER)
  • Maximum Rated Total Cooling Capacity
  • Evaporatively Cooled Condensers
  • Ice Storage Air Conditioners
  • Building Envelope Sealing
  • High Quality Insulation Installation (QII)
  • Quality Insulation Installation for Spray Polyurethane Foam
  • PV Field Verification Protocol

(Excerpted from the CEC Title 24 Residential Compliance Manual)