RESNET (Residential Energy Services Network) administers the HERS (Home Energy Rating System) Index, a standardized scoring system for residential building energy performance. RESNET-certified HERS Raters are qualified to inspect and rate the energy performance of homes using the HERS Index.
The HERS Index is widely used in new home construction to demonstrate code compliance, qualify for Energy Star certification, access mortgage incentives (such as energy-efficient mortgages), and inform buyers about anticipated energy costs. A HERS score of 100 represents the energy use of a standard reference home; lower scores mean better energy performance.
HERS Raters perform on-site inspections during and after construction, using approved software to model energy performance. They operate under RESNET-accredited Providers (called HERS Providers) who handle quality assurance oversight.
RESNET and the HERS Index are explicitly residential systems. A HERS Rater has no standing to rate commercial buildings, and the HERS Index does not apply to commercial building codes — which use ASHRAE 90.1 and IECC commercial provisions, not residential energy codes.
This guide is included for completeness and to help commercial buyers avoid confusion when evaluating professional credentials. A professional listing only RESNET/HERS credentials for a commercial energy engagement has limited relevant commercial qualifications.
For commercial energy auditing, look for CEM (Certified Energy Manager), ASHRAE BEAP (Building Energy Assessment Professional), or a PE (Professional Engineer) with mechanical/energy focus. For commercial new construction energy compliance, LEED AP BD+C is the more applicable credential.
The only scenario where RESNET experience has marginal relevance to commercial work is when a professional is transitioning from residential to commercial practice — in which case HERS background demonstrates energy modeling familiarity, but the commercial frameworks are substantially different.
| Factor | Details |
|---|---|
| Exam Format | Coursework completion + multiple field assessments under an accredited HERS Provider |
| Training Cost | $300–$500 for RESNET-accredited training programs (varies by provider) |
| Software | Approved HERS software required (REM/Rate, EnergyGauge, others) |
| Timeline | 3–6 months from training enrollment to full certification |
| Provider Requirement | Must maintain affiliation with a RESNET-accredited Provider during certification process |
| Field Reviews | Multiple supervised ratings required to demonstrate competency |
RESNET certifications are pursued through RESNET-accredited training providers and HERS Providers. The RESNET website maintains a directory of accredited training organizations and providers by state.
Official resource: resnet.us/hers-rater
Verification Note: EnergyStackHub does not independently verify certifications. We link to official verification resources. Commercial clients should independently verify any certifications claimed by professionals. RESNET maintains a searchable public rater registry at resnet.us.
For professionals transitioning to commercial energy work, or clients seeking commercial energy qualifications:
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