Rules and permitsENERGY STAR windows for Fort Wayne homes: U-factor and SHGC
For a Fort Wayne house, the standard ENERGY STAR target is a U-factor of 0.22 or lower with a solar heat gain coefficient of 0.17 or higher. Both numbers are on the white NFRC label of every certified window.
Fort Wayne's climate zone
ENERGY STAR splits the country into four window zones. Every ZIP code in Allen County, and the towns around it, falls in the Northern zone, the coldest of the four. The building code puts Allen County in climate zone 5A, a cold and humid zone.
Heating is the big energy load here, so start with how much heat a window lets out.
U-factor: heat going out
U-factor measures how fast heat passes through the whole window, glass and frame together. Lower is better. ENERGY STAR's Northern zone asks for 0.22 or lower. The next zone south, North-Central, allows 0.25.
Most of the difference comes from the glass package: two or three panes, low-E coatings, and argon or krypton gas in the gaps.
SHGC: sun coming in
Solar heat gain coefficient (SHGC) measures how much of the sun's heat gets through, from 0 to 1. In the South, low is better. In the Northern zone, ENERGY STAR sets a floor instead: 0.17 or higher, so a window still lets in some free winter sun.
The Northern zone has two trade-offs built in. A window with a U-factor of 0.23 or 0.24 still qualifies if its SHGC is 0.35 or higher, and one at 0.25 or 0.26 qualifies at 0.40 or higher. More winter sun makes up for a little more heat loss.
Reading the NFRC label
The National Fenestration Rating Council label on each certified window shows the U-factor, SHGC, visible light and, on some, air leakage. Ask for the label numbers of the exact window on your quote. A brand name alone doesn't tell you which glass package you're buying.
What changed with tax credits
The federal energy-efficient home improvement credit ended for windows placed in service after December 31, 2025, so a 2026 install doesn't earn it. NIPSCO still pays $50 per pane for ENERGY STAR low-E storm windows bought and installed in 2026. Our storm windows in Fort Wayne page has the details.
Comparing two window quotes
- Same frame material on both (vinyl, fiberglass, composite or wood)
- U-factor and SHGC from the NFRC label, window by window
- Insert or full-frame install
- Exterior trim: aluminum capping over the old frame, or new trim
- Lead-safe certification if the house was built before 1978
Typical prices for each frame are on the window replacement in Fort Wayne page.
Get your free in-home estimate
A few quick questions. Here's what happens next:
- We call you backTo hear about your house and pick a time that works for you.
- We measure everythingEvery window and wall, so your price is right the first time.
- You get it in writingProduct, trim, clean-up and a start date, all on one page.
