Conflicting Window U-Factor Documentation in a Compliance File
A program file for a new home includes a window schedule listing U-0.30 for all windows, a manufacturer's certificate showing U-0.32 for the specified model with argon, and a field label on one window showing U-0.35 for the same model without argon. The program requires an area-weighted average U-factor of 0.32 or lower for the glazing package. The home has 18 windows of equal size, 14 with the field label and 4 matching the certificate. The rater's report states the package averages 0.30. No shop drawings or order confirmation are in the file.
1. Assess whether the file supports the claimed 0.30 average and identify the documentation gaps.
Read the worked answer
The file is internally inconsistent. The schedule says 0.30, the certificate says 0.32 with argon, and a field label says 0.35 without argon. If 14 windows are the 0.35 units and 4 are 0.32, the area-weighted average is (14 x 0.35 + 4 x 0.32) / 18 = (4.90 + 1.28) / 18 = 6.18 / 18 = about 0.343. That exceeds the 0.32 requirement. The claimed 0.30 is not supported by any combination of the documents present.
The gaps are significant: no shop drawings or order confirmation to establish which units were actually supplied, no explanation for why field labels differ from the certificate, and no evidence that the rater verified labels rather than copying the schedule. The inspector should treat the package as unverified and likely noncompliant, and should require the order records, the manufacturer's certification for the exact supplied model and gas fill, and a corrected area-weighted calculation. The 0.30 figure should not be accepted without a basis.
2. The builder says the four certificate windows were upgraded and the labels are outdated. What must the builder provide, and how should the inspector document the resolution?
Read the worked answer
The builder's claim is plausible but unproven. The inspector should require documentation that ties each window to its actual configuration: order confirmation or packing list showing model, gas fill, and quantities; the manufacturer's certified U-factor for that exact configuration; and, where available, the permanent or temporary label for each unit. If labels are outdated, the builder must explain why and provide records that supersede them. A statement from the builder alone is not sufficient.
The inspector should document the discrepancy as found, the builder's explanation, the evidence submitted, and the corrected calculation. If the evidence shows 14 units at 0.35 and 4 at 0.32, the package fails and the remedy is replacement or an approved alternative that meets the average. If the evidence shows all 18 at 0.32 or better, the file can be corrected with a note explaining the superseded labels. Either way, the resolution should be dated, signed, and filed with the original discrepancy so an auditor can follow the trail. The inspector should not alter the original field notes.
3. What general lesson about compliance files does this case illustrate for the rater's report?
Read the worked answer
The case shows that a compliance claim must rest on the supplied configuration, not on the design intent or a single schedule line. Raters sometimes carry the specified U-factor into the report without reconciling it to the certificate, the order, and the field labels. When those sources disagree, the report's number is unsupported even if it happens to be correct.
A defensible file reconciles the design schedule, the manufacturer's certified values for the exact model and options, the order or shipping records, and the field verification. The area-weighted calculation should show the quantity and U-factor of each window type so the arithmetic can be checked. Discrepancies should be resolved before the report is issued, and any post-issuance correction should be documented rather than silently edited. The inspector's role is to test the claim against independent evidence, and a file that cannot survive that test is a finding regardless of the builder's assurances.