Chatsworth, CA: Climate Zone, Risk and Window Requirements

Local risk and climate data for Chatsworth, CA are below, translated into plain terms for a window buyer rather than left as raw codes. Use it to check a proposed spec before you sign, not just to browse.

Licenses checked September 30, 2026 · California Contractors State License Board

3BIECC climate zone · ENERGY STAR South-Central zone

What zone 3B means for a Chatsworth window

Chatsworth falls in IECC climate zone 3B, and ENERGY STAR separately groups Los Angeles County into its South-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 Chatsworth.

A Los Angeles-Long Beach-Anaheim, CA 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 5.5 mi away.

Storm and weather risk around Chatsworth

FEMA scores Los Angeles County's winter-weather risk as Relatively Moderate and its flood risk as Very High.

Winter risk in Chatsworth weighs on U-factor and condensation resistance; flood risk weighs more on sill height and drainage detailing than on the glass package.

Treat these as two separate conversations with a Chatsworth contractor, not one.

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 Chatsworth 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 Chatsworth

Oldest license first, newest last, pulled directly from the state's file. This list isn't for sale.

Progressive Insulation & WindowsWindow and glass contractor · licensed 44 years · 91311Verify license
S C Protective Glass Laminates & CoatingsWindow and glass contractor · licensed 28 years · 91311Verify license
California Deluxe WindowsWindow and glass contractor · licensed 26 years · 91311Verify license
Silva Glassworks INCWindow and glass contractor · licensed 18 years · 91311Verify license
J Michael Designs INCWindow and glass contractor · licensed 14 years · 91311Verify license
Intrepid Glass & Mirror INCWindow and glass contractor · licensed 14 years · 91311Verify license
German Custom Glass And MirrorWindow and glass contractor · licensed 13 years · 91311Verify license
Fine Windows & Doors Replacement INCWindow and glass contractor · licensed 12 years · 91311Verify license
My Glass GuyWindow and glass contractor · licensed 10 years · 91311Verify license
The Sliding Door CompanyWindow and glass contractor · licensed 10 years · 91311Verify license
Lance GlassWindow and glass contractor · licensed 7 years · 91313Verify license
Heart & Soul Custom Window & Glass Door Installation INCWindow and glass contractor · licensed 6 years · 91311Verify license

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