Window Climate Specs for Sun Valley, CA
Sun Valley sits in IECC climate zone 3B, which sets the energy-performance bar for any window installed here. Below that, a short list of Sun Valley's longest-licensed window contractors can turn a spec into an actual installed window.
Licenses checked · California Contractors State License Board
3BIECC climate zone · ENERGY STAR South-Central zone
Sun Valley's climate zone, in plain terms
Sun Valley falls in IECC climate zone 3B, and ENERGY STAR separately groups Los Angeles County into its South-Central zone for window certification.
Those two numbers, not the brand on the box, set the U-factor and SHGC worth checking on any quote you get in Sun Valley.
A Los Angeles-Long Beach-Anaheim, CA contractor who can't name either one on request is worth a second question before you sign.
Data: U.S. EPA / DOE, ENERGY STAR, ENERGY STAR Version 7.0 Climate Zones by County/ZIP (Windows, Doors, and Skylights) (V7.0); Pacific Northwest National Laboratory (DOE Building America), Guide to Determining Climate Zone by County: Building America and IECC 2021 Updates (PNNL-33270) (2021 IECC), from the nearest NOAA station 2.1 mi away.
What FEMA's risk data says about Sun Valley
FEMA scores Los Angeles County's winter-weather risk as Relatively Moderate and its flood risk as Very High.
Winter risk in Sun Valley weighs on U-factor and condensation resistance; flood risk weighs more on sill height and drainage detailing than on the glass package.
Treat these as two separate conversations with a Sun Valley contractor, not one.
- Strong wind
- Relatively Moderate
- Winter weather
- Relatively Moderate
Data: FEMA, National Risk Index for Natural Hazards - County-level table, v1.20 (v1.20, December 2025).
Guides to finish before Sun Valley window bids come in
- How to Read an NFRC Window Label Four numbers on one sticker decide most of a window's real-world performance. Here's what each one means.
- ENERGY STAR Window Criteria by Climate Zone ENERGY STAR splits the country into four zones, each with its own numbers. Here they are, and why the Northern zone works backward from the other three.
- Impact Windows vs. Shutters in Florida's Hurricane Zones Florida gives homeowners two paths to a protected opening. Here's how each one is tested, and where the HVHZ raises the bar further.
Sun Valley's longest-licensed window installers
Oldest license first, newest last, pulled directly from the state's file. This list isn't for sale.
- Nathan's Glass & Mirror INCVerify license
- J D Gerred GlazingVerify license
- Redro Construction INCVerify license
- GG Glass & Shower DoorsVerify license