Check U-factor & SHGC against 2023 Florida Building Code — Energy Conservation (8th Edition)
Screening tool only — not a permit submittal. This checks a single window/door's NFRC-labeled U-factor and SHGC against the Florida prescriptive energy path (R402.1.2). Whole-building compliance can also be shown via the Simulated Performance (R405), UA-alternative (R402.1.5), or ERI (R406) paths — those aren't covered here. Also confirm against the project's approved Form R405 or Energy Performance Level Display Card before install.
Project Inputs
Florida is split into just two zones under the FBC. All HVHZ counties are Zone 1.
Replacements and additions generally must meet the same fenestration limits when replacing the entire product. Sash-only repairs are typically exempt.
Impact-rated products may use a relaxed U-factor limit in Zone 2 (footnote j, R402.1.2).
NFRC Label Values
Lower is better. Typical impact vinyl: 0.28–0.40. Aluminum impact: often 0.55–0.70.
Lower is better in Florida (blocks more solar heat). Range 0–1. Typical impact tinted: 0.20–0.30.
Skylights have separate, looser limits under FBC-EC.
Result
✓Meets FBC prescriptive limits
ENERGY STAR (Southern zone): —
Prescriptive limits: 2023 Florida Building Code — Energy Conservation, Table R402.1.2 (Insulation & Fenestration by Component). Impact-rated footnote j applies in Zone 2. ENERGY STAR criteria: Version 7.0, Southern zone (all of Florida).
How the limits work
Climate Zone
U-Factor (max)
SHGC (max)
Impact-Rated U-Factor Alt.
Skylight U (max)
Zone 1 Miami-Dade, Broward, Monroe
0.50
0.25
— (not stated)
0.75
Zone 2 Rest of Florida
0.40
0.25
0.65 (impact-rated)
0.65
Values from Table R402.1.2, 2023 FBC-EC (8th Edition). SHGC limit is uniform across both Florida zones. The Zone 2 impact-rated 0.65 alternate is footnote j — Zone 1 has no equivalent published alternate, so impact products in Miami-Dade/Broward/Monroe must meet the 0.50 U-factor. Skylight values per Table R402.1.2 (skylight column).