After the initial model field verification and diagnostic testing is completed as specified in RA2.6.2, the builder, or the builder’s authorized representative shall determine a sampling procedure to be used, and shall designate the dwelling units to include in the group of dwellings that require HERS verification. The maximum number of dwelling units allowed in a sample group may range from five, to seven, to thirty as described in Sections RA2.6.3.3, RA2.6.3.4, and RA2.7 respectively.

If multiple measures requiring HERS verification are installed, each dwelling unit in a designated group shall have the same measures requiring HERS verification as the other dwelling units in the designated group. If some dwelling units have installed a different set of measures requiring HERS verification, those dwelling units shall be in a separate group.

If the dwelling units in a designated group have multiple measures that require HERS verification, sample testing for individual measures may be conducted in any of the dwelling units in the group - it is not required that all of the sample tests for all of the individual measures be completed in the same dwelling unit. Individual measures shall be allowed to be included in a group regardless of whether compliance requires one sample test, or if compliance requires more than one sample test (up to 100% sample test rate) be reported for such individual measures.

Dwelling units in a designated group shall all be located within the same enforcement agency jurisdiction and subdivision or multifamily housing development. Refer also to Section RA2.8 for requirements for sample groups applicable to alterations.

If dwelling units have central forced-air space conditioning equipment that introduces outside air into the conditioned space utilizing means that connect outside air ventilation ducts directly to the dwelling unit’s central forced air duct system (Central Fan-Integrated Ventilation System or CFI Ventilation System), the CFI ventilation technology shall be considered a separate measure for HERS verification sampling purposes, and dwellings with CFI ventilation systems shall be placed in separate groups from other dwelling units that do not utilize CFI ventilation technology.

Registration of the first Certificate of Installation, for the first dwelling in a sample group shall be required to “open” a new group. The date of the responsible persons registration signature for the first Certificate of Installation for the group shall establish the start date for the group. Additional dwellings may be entered into the registry, and included in an “open” group over a period of time subject to registration of the Certificate of Installation documents for each additional dwelling. However the group shall not remain “open” to receive additional dwellings for a period longer than six months after the start date of the group. A group may be “closed” at any time after the group has been “opened” at the option of the builder or builder’s authorized representative, thus the size of a “closed” group may range from a minimum of one dwelling to a maximum of seven dwellings. When a group becomes classified as “closed”, no additional dwellings shall be added to the group.

The following criteria shall be met as prerequisite to attaining HERS verification compliance for the group:

1. All of the dwelling units contained in the sample group have been identified. A maximum of seven dwellings are allowed to be included in a “closed” sample group for HERS compliance.
2. Installation of all the measures that require HERS verification has been completed in all the dwellings that are entered in the group, and registration of the Certificates of Installation for all the dwellings entered in the group has been completed.
3. The group has been classified as a “closed” group in the Provider data registry.
4. At the request of the builder or the builder’s authorized representative, a HERS Rater shall randomly select one dwelling unit from the “closed” sample group for field verification and diagnostic testing. If the dwelling unit meets the compliance requirements, this “tested” dwelling and also each of the other “not-tested” dwellings in the group shall receive a registered Certificate of Verification.

The following criteria shall be met as prerequisite to attaining HERS verification compliance for the group:

1. At least one dwelling unit from the sample group has been identified. A maximum of five dwellings are allowed to be included in an “open” sample group for HERS compliance.
2. Installation of all the measures that require HERS verification shall be completed in all the dwellings that are entered in the group, and registration of the Certificates of Installation for all the dwellings entered in the group has been completed.
3. At the request of the builder, or the builder’s authorized representative, a HERS Rater shall randomly select one dwelling unit from those currently entered into the “open” sample group for field verification and diagnostic testing. If the dwelling unit meets the compliance requirements, the “tested” dwelling and also each of the other “not tested” dwellings currently entered into the group shall receive a registered Certificate of Verification. If less than five dwelling units have been entered into the group, the group shall be allowed to remain “open” and eligible to receive additional dwelling units. Dwelling units entered into the “open” group subsequent to the compliant HERS verification of the “tested” dwelling shall also receive a registered Certificate of Verification as a “not tested” dwelling subject to receipt of the registered Certificate of Installation by the HERS Provider data registry for the dwelling. The group shall be “closed” when it reaches the limit of five dwellings or when the six month limit for “open” groups has been exceeded, or when the builder requests that the group be closed.

The builder or the HERS Rater may request removal of untested dwelling units from a group by notifying the HERS Provider prior to selection of the dwelling sample that will be tested from an “open” or “closed” group and shall provide justification for the change. Removed dwelling units shall be field verified and diagnostically tested individually or shall be included in a subsequent group for sampling.

There are exceptions to the requirement to have completed Certificate of Installation data entered into the HERS Provider data registry prior to selection of the dwelling unit to be tested in a group. Some HERS measures require multiple verifications during the construction process. A sample group is not required to be closed before HERS field verification and diagnostic testing can begin for the following measures. For these measures the HERS Rater is allowed to randomly select the dwelling unit to be field verified from those that are at the proper stage of construction to enable the first of the multiple verifications to be completed.

1. Quality Installation of Insulation measure requires inspection of the air barrier and inspection of the insulation behind tubs and showers at framing rough-in. Verification of the wall, floor and ceiling insulation must be completed prior to drywall installation. Attic insulation installation may require follow-up verification.
2. Buried Ducts measure requires verification of the duct design prior to verification of the attic insulation.
3. Duct Surface Area requires verification of the duct design prior to installation of the attic insulation.

The HERS Rater, with no direction from the installer or builder, shall randomly select one dwelling unit from a “closed” sample group for field verification and diagnostic testing upon receiving the builder’s or builder representative’s request for HERS verification of that group. Alternatively, the HERS Rater shall randomly select one dwelling unit from the dwellings currently entered into an “open” sample group upon receiving the builder’s or builder representative’s request for HERS verification of that group. The HERS Rater shall diagnostically test and field verify the selected dwelling unit. The HERS Rater shall enter the test and/or field verification results into the HERS Provider data registry regardless of whether the results indicate a pass or fail. If the test fails, then the failure must be entered into the Provider’s data registry even if the installer immediately corrects the problem. In addition, the procedures in Section RA2.6.4 shall be followed.

If field verification and diagnostic testing determines that the requirements for compliance are met, the HERS Rater shall enter the test results into the HERS Provider data registry. Whereupon the Provider shall make available to the HERS Rater, the builder, the enforcement agency, and other approved users of the HERS Provider data registry, a registered copy of the Certificate of Verification for the “tested” dwelling, and for all other “not tested” dwelling units entered in the group at the time of the sample test. The registered Certificate of Verification shall report the successful diagnostic testing results and conclusions regarding compliance for the tested dwelling unit. The registered Certificate of Verification shall also provide:

1. Building permit number for the dwelling unit.
2. Registration Number that conforms to the numbering convention specified in Reference Joint Appendix JA7.
3. Group Number that conforms to the numbering convention specified in Reference Joint Appendix JA7.
4. Time and date stamp of the Provider’s issuance of the registered Certificate of Verification.
5. Provider’s logo, water mark, or official seal.
6. Indication that the dwelling was a “tested” dwelling, or was a “not-tested” dwelling in a sample group.

Whenever the builder changes subcontractors who are responsible for a feature that is being diagnostically field verified and tested, the builder shall notify the HERS Rater of the subcontractor change, and terminate sampling for any affected groups. All dwelling units utilizing features that require HERS verification for compliance that were installed by previous subcontractors or were subject to verification and testing under the supervision of a previous HERS Provider, for which the builder does not have a completed Certificate of Verification, shall be individually tested or included in a separate group for sampling. Dwelling units with installations completed by new subcontractors shall be individually tested or shall be included in a new sampling group.

The HERS Rater shall not notify the builder when sample testing will occur prior to the completion of the work that is to be tested, or prior to registration of the Certificate of Installation.

The HERS Provider shall “close” any “open” group within 6 months after the earliest signature date shown on any Certificate of Installation for a dwelling entered in the group. When such group closure occurs, the HERS Provider shall notify the builder that the group has been “closed”, and require that a sample dwelling shall be selected for field verification and diagnostic testing by a HERS Rater if field verification has not yet been conducted on a sample dwelling entered in the group.

The HERS Rater shall randomly select for re-sampling one of the remaining untested dwelling units in the group for retesting of the feature that failed. If the failed dwelling was entered in a “closed” group, and the testing of the second randomly selected dwelling unit in the group confirms that the requirements for compliance credit are met on that unit, then the dwelling unit with the initial failure shall not be considered an indication of failure in the remaining untested dwelling units in the group. The HERS Rater shall transmit the re-sample test results to the HERS Provider registry, whereupon the Provider shall make available to the HERS Rater, the builder, the enforcement agency, and other authorized users of the HERS Provider data registry, a registered copy of the Certificate of Verification for the remaining dwelling units in the group including the dwelling unit in the re-sample.

If field verification and diagnostic testing of the second sample results in a failure, the HERS Rater shall report the second failure to the HERS Provider, the builder, and the enforcement agency. All dwelling units in the group must thereafter be individually field verified and diagnostically tested to confirm compliance for the feature that failed to comply with re-sampling. In cases where corrective action would require destruction of building components, the builder may choose to reanalyze compliance and choose different measures that will achieve compliance. In this case a new Certificate of Compliance shall be completed and submitted to the HERS Provider, the HERS Rater, and the enforcement agency. Even with a new Certificate of Compliance, the dwelling unit must be individually field verified and diagnostically tested. Upon verification of compliance, the HERS Rater shall enter the test results into the HERS Provider data registry. Whereupon the Provider shall make available to the HERS Rater, the builder, the enforcement agency, and other authorized users of the HERS Provider data registry, a registered copy of the Certificate of Verification for each individual dwelling in the group.

The HERS Rater shall randomly select for re-sampling one of the remaining untested dwelling units in the group for retesting of the feature that failed. If the failed dwelling was entered in an “open” group, and there are no other untested dwellings entered in the “open” group at the time of the failed HERS verification, subsequent dwellings entered into the “open” group shall not receive a Certificate of Verification until a second dwelling in the “open” group is tested and successfully complies. If the subsequent testing of the second dwelling unit in the group confirms that the requirements for compliance credit are met on that unit, then the dwelling unit with the initial failure shall not be considered an indication of failure in the untested dwelling units in the group. The HERS Rater shall transmit the compliant re-sample test results to the HERS Provider data registry, whereupon the Provider shall make available to the HERS Rater, the builder, the enforcement agency, and other authorized users of the HERS Provider data registry, a registered copy of the Certificate of Verification, for the re-sampled dwelling, and the remaining not yet tested dwelling units entered in the “open” group at the time of the re-sample test, and the group shall be allowed to remain open and eligible to receive additional dwelling units. Dwelling units entered into the “open” group of up to 5 dwellings following the successful HERS verification of the re-sampled dwelling shall receive a Certificate of Verification as a “not tested” dwelling subject to registration of the Certificate of Installation by the HERS Provider data registry for the dwelling.

If field verification and diagnostic testing of the second sample results in a failure, the HERS Rater shall report the second failure to the HERS Provider, the builder, and the enforcement agency, and the Provider shall require the “open” group to be “closed”. All remaining untested dwelling units entered in the group at the time of the re-sample must thereafter be individually field verified and diagnostically tested. In cases where corrective action would require destruction of building components, the builder may choose to reanalyze compliance and choose different measures that will achieve compliance. In this case, a new Certificate of Compliance shall be completed and submitted to the HERS Provider, the HERS Rater, and the enforcement agency. Even with a new Certificate of Compliance, the dwelling unit must be individually field verified and diagnostically tested. Upon verification of compliance, the HERS Rater shall enter the test results into the HERS Provider data registry. Whereupon the Provider shall make available to the HERS Rater, the builder, the enforcement agency, and other authorized users of the HERS Provider data registry, a registered copy of the Certificate of Verification for each individual dwelling in the group.

Builders shall offer to provide the necessary field verification and diagnostic testing services and any necessary corrective action at no charge to building owners (for a definition of “building owner” and of other terms used, see Reference Joint Appendix JA1) in occupied dwelling units in the group. Builders shall report to the HERS Provider the identifying location of any dwelling unit in which the building owner or occupant declines field verification and diagnostic testing and corrective action. The HERS Provider shall verify that the builder has made this offer. If a building owner of a dwelling unit declines this offer, field verification, diagnostic testing, and corrective action will not be required for that dwelling unit and the dwelling unit will no longer be considered a part of the group. If a building owner accepts this offer, the builder shall take corrective action, and the HERS Rater shall conduct field verification and diagnostic testing to verify that problems have been corrected. Upon verification of compliance, the HERS Rater shall transmit the test results to the HERS Provider data registry. Whereupon the Provider shall make available to the HERS Rater, the builder, the enforcement agency, and other authorized users of the HERS Provider data registry, a registered copy of the Certificate of Verification for the dwelling unit.

The HERS Provider shall file a report with the enforcement agency explaining all actions taken (including field verification, diagnostic testing, corrective action, offers to building owners for testing and corrective action, and/or building owner declines of such offers) to bring into compliance dwelling units for which full testing has been required. If corrective action requires work not specifically exempted by the CMC or the CBC, the builder shall obtain a permit from the enforcement agency prior to commencement of any of the work.

Corrections to avoid reporting a failure to the HERS Provider data registry shall not be made to a sampled dwelling unit after the HERS Rater selects the sample dwelling unit. If it is evident that such corrections have been made to a sampled dwelling unit to avoid reporting a failure, field verification and diagnostic testing shall be required for 100 percent of the dwelling units in the group.