What Is an ECC-Rater?
The independent third party who field-verifies and diagnostically tests the measures a Title 24 report relies on. Until 1 January 2026 this role was called a HERS rater — the tests did not change, the programme was renamed.
The rename, plainly
On 1 January 2026 the field verification and diagnostic testing side of the HERS Program moved into the new Energy Code Compliance (ECC) Program. HERS Providers became ECC-Providers and HERS raters became ECC-Raters, and the testing provisions now sit in the Energy Code itself rather than in separate HERS regulations.
The HERS Program still exists, but its remaining scope is whole-house ratings and home energy audits — which no longer demonstrate Title 24 compliance. So if a document, a contractor or a website tells you your project needs a HERS rater, they mean this, using the former name.
What they actually do
An ECC-Rater tests the things nobody can confirm by looking. Duct leakage. Refrigerant charge. Fan watt draw and airflow. Quality Insulation Installation, inspected before the walls close. Whole-building airtightness where a design depends on it.
Every one of those is a measure the compliance calculation took credit for and that would otherwise be taken on trust. That is the whole design of the arrangement: the measures that can be verified visually are inspected by the building department, and the measures that cannot get an instrument and an independent technician.
Independent of both sides
The rater is not employed by the contractor whose work is being tested, and not by the building department approving it. Results are registered through an ECC-Provider's data registry, which is the authoritative record the building department works from.
Registration is what gives the result its weight. It is not a certificate handed to the builder — it is filed, and a fail is filed too. A failed verification has to be corrected and re-verified.
Not the same as acceptance testing
The nonresidential equivalent is acceptance testing, documented on NRCA forms. It is a different programme with different certification: lighting controls and mechanical systems require a technician certified through an approved provider, while covered process tests may be performed by a field technician.
A commercial project does not have ECC verification and a house does not have acceptance testing. Confusing the two is common, and it leads to hiring the wrong specialist.
Engage one early, for one reason
The tests need physical access. Ducts have to be reachable, cavities have to be open for QII, the mechanical system has to be running. Every one of those conditions disappears as the build finishes.
Which measures need verification is stated on the design-stage certificate, so it is knowable from the start. Reading that list at the beginning and booking accordingly is the difference between a routine visit and opening up finished work.