Charleston, SC Climate Specs + Top-Rated Window Installers
ENERGY STAR groups Charleston County into its South-Central zone, the U-factor and SHGC target worth checking against any quote you get in Charleston. Below that spec discussion sit 10 installers, their order set by Google rating, since Charleston 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
3AIECC climate zone · ENERGY STAR South-Central zone
What zone 3A means for a Charleston window
Moisture and glass performance are handled by different parts of a window's spec sheet, and a Charleston buyer benefits from checking both instead of assuming one implies the other.
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 4.1 mi away.
Storm and weather risk around Charleston
FEMA rates Charleston County's hurricane risk as Very High and its wind risk as Relatively Moderate.
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 Charleston home.
Ask specifically about design pressure and impact rating for Charleston, not just energy performance, if either risk rating comes back on the high side.
- Hurricane
- Very High
- 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 Charleston 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.
10 top-rated window installers near Charleston, SC
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.
- Charleston Roofs and WindowsGoogle reviews
- Top Tier Home ImprovementGoogle reviews
- Icon Window and DoorGoogle reviews
- Southern Industries Home ImprovementsGoogle reviews
- Century Commercial Glass SystemsGoogle reviews
- The Window Source of the LowcountryGoogle reviews
- The Glass GuruGoogle reviews
- Window NationGoogle reviews
- Coastal Siding & WindowsGoogle reviews
- MuhlerGoogle reviews