Houston, TX Climate Specs + Top-Rated Window Installers
ENERGY STAR groups Harris County into its Southern zone, the U-factor and SHGC target worth checking against any quote you get in Houston. Below that spec discussion sit 10 installers, their order set by Google rating, since Houston is outside this site's window license file. A high rating is worth a look, not a finished decision.
Google Maps ratings checked · How we rank
2AIECC climate zone · ENERGY STAR Southern zone
Houston's climate zone, in plain terms
Houston falls in IECC climate zone 2A, and ENERGY STAR separately groups Harris County into its Southern 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 Houston.
A Houston-Pasadena-The Woodlands, TX 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 2.3 mi away.
What FEMA's risk data says about Houston
FEMA rates Harris County's hurricane risk as Very High and its wind risk as Very 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 Houston home.
Ask specifically about design pressure and impact rating for Houston, not just energy performance, if either risk rating comes back on the high side.
- Hurricane
- Very High
- Strong wind
- Very High
- 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 Houston 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.
Houston's top-rated window installers, by Google
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.
- I-Window RemodelingGoogle reviews
- Reliable WindowsGoogle reviews
- Longhorn Windows and RoofingGoogle reviews
- Window World of HoustonGoogle reviews
- The Window ExpertsGoogle reviews
- Vindov & GlassGoogle reviews
- Maverick Windows HoustonGoogle reviews
- Allstate Windows & SidingGoogle reviews
- Mr Windows HoustonGoogle reviews
- Pella Windows and Doors Showroom of Houston, TXGoogle reviews