607 Sample Verification Process

607.1
A complete set of Sampling Verifications shall be performed at a minimum rate of twenty percent (20%) within a given Sample Set. At a minimum, a Certified Rater shall oversee this process.

The minimum quantity of Sampling Verifications for each Sampled Feature within a Sampled Set shall be calculated by multiplying the number of Sampled Features by 20% and rounding the result up to the nearest whole number.¹ (Projects containing less than 12 Sampled Features would not benefit from the Sampling process.)

^{1For example, consider a 100-unit Sampled Project. The minimum quantity of Verifications for a given Sampled Feature is 100 – 10 (Qualification Set) = 90, then 90 * 0.2 = 18. Note: Qualification Set number may vary depending on Failures but always requires a minimum 5 completed + 5 consecutive without Failure.
6Representative selection includes but is not limited to location within a building or Community, unit type, exposure, orientation, unique options, changes in construction crews, etc.}

Raters operating under a Sampling Provider may complete the Sampling Verifications collectively on a single Dwelling Unit or distribute the tests and inspections across several Dwelling Units within a given Sample Set, provided the total number of individual tests and inspections meets or exceeds 20%. All Sampled Features shall be verified, at least once, for each unit type.

The Rater shall select the instances (e.g., which duct systems will be tested) of Sampled Features (e.g., duct leakage) that are subject to Verification. The selected instances shall not be announced in advance. The instances that are selected for Verification shall be representative⁶ of the total group of Sampled Features. Verifications shall be spread across the beginning, middle, and end of the installation timeline for each Sampled Feature.

Sample Sets that include multifamily buildings with five (5) units or more per building shall have a minimum of one unit verified per building.

A Sampled Feature that does not meet its Threshold Specification is a Failure. Sampling is permitted to continue for each Sampled Feature until a Failure occurs. All Failures shall be addressed according to the Procedures for Resolving Failures.