Ellisville, MO Climate Specs + Top-Rated Window Installers
Ellisville sits in IECC climate zone 4A, which sets the energy-performance bar here no matter who ends up installing your windows. A window license file doesn't cover Ellisville on this site, so Google Maps supplies the 6 ranked names you see below. Checked October 2026.
Google Maps ratings checked · How we rank
4AIECC climate zone · ENERGY STAR North-Central zone
What zone 4A means for a Ellisville window
Ellisville falls in IECC climate zone 4A, and ENERGY STAR separately groups St. Louis County into its North-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 Ellisville.
A St. Louis, MO-IL 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 Ellisville
FEMA rates St. Louis County's hurricane risk as Very Low and its wind risk as Relatively High.
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 Ellisville home.
Ask specifically about design pressure and impact rating for Ellisville, not just energy performance, if either risk rating comes back on the high side.
- Hurricane
- Very Low
- Strong wind
- Relatively High
- Winter weather
- Very High
Data: FEMA, National Risk Index for Natural Hazards - County-level table, v1.20 (v1.20, December 2025).
Guides to finish before Ellisville 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.
6 top-rated window installers near Ellisville, MO
The order below weighs a Google rating against its review count, the same way this site weighs a U-factor against a brochure claim: on the number, not the name. Treat it as a rating, never as proof of a license, bond or HVHZ approval.
- Zen Windows of St. LouisGoogle reviews
- Exterior Building SolutionsGoogle reviews
- West County Siding & WindowsGoogle reviews
- Exterior Siding Solutions, LLCGoogle reviews
- Brandon J RoofingGoogle reviews
- Wildwood Roofing & ConstructionGoogle reviews