Waltham, MA Climate Specs + Top-Rated Window Installers
Waltham sits in IECC climate zone 5A, which sets the energy-performance bar here no matter who ends up installing your windows. A window license file doesn't cover Waltham on this site, so Google Maps supplies the 10 ranked names you see below. Checked September 2026.
Google Maps ratings checked · How we rank
5AIECC climate zone · ENERGY STAR Northern zone
Waltham's climate zone, in plain terms
Waltham falls in IECC climate zone 5A, and ENERGY STAR separately groups Middlesex 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 Waltham.
A Boston-Cambridge-Newton, MA-NH 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 6.1 mi away.
What FEMA's risk data says about Waltham
Middlesex County's hail risk sits at Very Low and its wildfire risk at Relatively Low, according to FEMA's National Risk Index.
Hail risk matters for glass and screen durability in Waltham; wildfire risk matters more for the frame material and nearby vegetation than for the glass itself.
Either way, it's a reasonable question to bring to a Waltham installer before you settle on a product line.
- Hurricane
- Relatively High
- Strong wind
- Relatively High
- 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 Waltham 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.
Waltham'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.
- Fisher WindowsGoogle reviews
- Rydica home solutionsGoogle reviews
- DLM RemodelingGoogle reviews
- Window World of BostonGoogle reviews
- Top Sash Windows & DoorsGoogle reviews
- Three Sons Window & More Inc.Google reviews
- Power Home RemodelingGoogle reviews
- Harvey Building ProductsGoogle reviews
- E.M. Snow, Inc.Google reviews
- Waltham window and doorGoogle reviews