TR-8 Fenestration Thermal Values and Ratings
1RCNY IA3
U-factors of installed fenestration shall be verified by visual inspection for conformance with the U-factors identified in the construction drawings, either by verifying the manufacturer’s NFRC labels or, where not labeled, using the ratings in ECC Tables 303.1.3(1) and (2).
1RCNY IIA3
U-factors and SHGC values of installed fenestration shall be visually inspected for conformance with the U-factors and SHGC values identified in the construction drawings by verifying the manufacturer’s NFRC labels or, where not labeled, using the ratings in ECC Tables 303.1.3(1), (2) and (3). Where ASHRAE 90.1 is used, visible light transmittance values shall also be verified.
Details
SIGN-ON / Inspect / SIGN-OFF (package)Beyond the Label: Understanding Whole-Assembly The
While verifying NFRC labels confirms a product's rated performance, the TR-8 inspection for fenestration thermal values goes further — it evaluates how the installed fenestration system performs as part of the complete building envelope assembly under NYC's Energy Conservation Code (ECC).
The ECC Tables 303.1.3(1), (2), and (3) establish maximum allowable U-factors and minimum Solar Heat Gain Coefficient (SHGC) thresholds for the entire glazing system, not just individual products. This means the thermal performance of the frame, spacer, glazing layers, and installation method must collectively meet code — even if each individual component is rated correctly on its label.
Where this matters most in NYC construction:
- High-rise curtain wall systems — where the framing system's thermal bridging can significantly degrade the assembly U-factor below what individual product ratings suggest
- Mixed-use buildings using ASHRAE 90.1 — which additionally requires verification of Visible Light Transmittance (VLT) values
- Gut-renovated brownstones — where new fenestration is installed in existing masonry openings, requiring field verification that thermal performance matches the energy compliance documents filed with the DOB
Relationship to blower door and air infiltration testing: A fenestration assembly that passes U-factor verification but fails air sealing can undermine the building's overall thermal envelope performance. EZTR1 inspectors flag installation deficiencies — such as missing sill flashing, inadequate sealant at jambs, or thermal bridges at rough openings — that affect the assembly's real-world thermal performance beyond what the label alone confirms.
Need a TR-8 thermal values inspection for your NYC project? Contact EZTR1 to schedule with a certified special inspector.