Window Climate Specs for Federal Way, WA
ENERGY STAR groups King County into its Northern zone, which is the U-factor and SHGC target worth checking against any quote you get in Federal Way. The longest-licensed window contractors based in Federal Way are listed below the climate data.
Licenses checked · Washington State Department of Labor & Industries
4CIECC climate zone · ENERGY STAR Northern zone
What zone 4C means for a Federal Way window
Federal Way falls in IECC climate zone 4C, and ENERGY STAR separately groups King County into its Northern 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 Federal Way.
A Seattle-Tacoma-Bellevue, WA 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 5.7 mi away.
Storm and weather risk around Federal Way
Neither rating changes a window's energy label, but both are exactly what impact-resistance and design-pressure ratings are built to answer for a Federal Way home.
Ask specifically about design pressure and impact rating for Federal Way, not just energy performance, if either risk rating comes back on the high side.
- Strong wind
- Very Low
- Winter weather
- Relatively High
Data: FEMA, National Risk Index for Natural Hazards - County-level table, v1.20 (v1.20, December 2025).
Guides to finish before Federal Way 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.
Window installers with the longest license records in Federal Way
Oldest license first, newest last, pulled directly from the state's file. This list isn't for sale.
- Pacific Window Systems INCVerify license
- Clear Choice Windows LLCVerify license
- Niemen Glass CO LLCVerify license
- King County Window & GlassVerify license