Window Retrofits- . NCO Inc. . 2025

Upgrading Windows for Wildfire Safety:

Windows are one of the most fragile defenses your home has against wildfire. During a blaze, single-pane or non-tempered windows can shatter from the intense heat, allowing flames and embers to breach your home. Embers, which can travel miles on the wind, are just waiting for the chance to land on your window frame or slip through cracks. Upgrading to double-paned, tempered glass and adding ember-resistant screens can transform your windows from a weak point into a fortified barrier. Meeting California's Wildfire Mitigation Program Code standards for windows is crucial to keeping radiant heat, flames, and embers out—because in a wildfire, every layer of defense counts.

Key Points:

Install double-paned tempered glass for superior heat resistance and durability.
Replace windows with non-combustible frames to prevent fire intrusion.
Upgrade existing windows with tight-fitting ember-resistant screens.
Ensure windows meet building codes and integrate well with your home’s exterior.

This section details requirements for strengthening windows in your wildfire hardening project to meet California's Wildfire Mitigation Program Code standards. Here's a breakdown:

Window Retrofits:

Window Replacements:

Replace non-compliant or damaged windows with double-paned tempered glass windows. The frame must be non-combustible.
You are responsible for removing and disposing of the old windows at an approved site.

Window Screen Retrofits:

For existing windows, install tight-fitting aluminum screens in window channels to prevent ember intrusion. The frame should be non-combustible, and the screen mesh should be 18x16 mesh with a minimum wire diameter of 0.21mm.

Installation Standards:

Follow the manufacturer's instructions and relevant building codes (CBC or CRC) for window installation, flashing, and exterior walls. This ensures proper integration with your home's exterior.

Additional Considerations:

Window retrofits must comply with other building codes for emergency escape, fall protection, natural light/ventilation, and tempered glazing.

Compliance References:

CBC (California Building Code): Sections 708A, 104.9, 1204.2, 1202.5.1, 1404.4, 1404.13, 2406
CRC (California Residential Code): Sections R337.8, R104.9, R303.1, R703, R703.4, R310.2, R312.2, R308

Tempered Glass: A Wildfire-Resistant Upgrade

Double-paned tempered glass windows are a critical upgrade for wildfire home security due to their exceptional strength and heat resistance. Tempered glass undergoes a specialized process of heating and rapid cooling, making it up to four times stronger than standard glass. This increased durability allows tempered panes to withstand intense radiant heat and resist breaking when exposed to flame or flying embers. In a wildfire, where single-pane or non-tempered windows often fail, double-paned tempered glass provides a robust barrier, reducing the chances of shattering and preventing fire intrusion. Combined with ember-resistant screens, these windows create a fortified defense that offers unparalleled protection for your home.

Resource provided by California Energy Contractors

Disclaimer: The California Wildfire Mitigation Program Home Hardening Initiative recommends the following measures to retrofit a residence. Please note that not all retrofits listed are available in the Lake County Home Hardening Program.