Windows

What it is.

The glazed openings in your walls, counted by what the glass is rather than what the frame looks like. Single pane is one layer of glass. Double pane is two layers with a sealed gap. Exterior shutters that actually close over the glass are treated separately.

Why it matters.

Glass fails under heat before the wall around it does. A fire burning some distance away can deliver enough radiant heat through a window to break it, and once the glass is gone the opening lets heat and embers straight into the room. Nothing has to touch the house for this to happen.

What good looks like.

Multi-pane glazing throughout, or functional exterior shutters that close over the glass, with frames in sound condition and no cracked panes.

How it is judged.

SFM 12-7A-2 applies a 150 kilowatt flame for eight minutes to the glazing assembly. Multi-pane glass qualifies because the outer pane sacrifices itself while the inner pane holds the envelope. Functional exterior shutters are an accepted alternative. California insurers are required to account for windows under 2644.9(d)(1)(B)2.d.

What we will ask you.

"Are your windows single pane or double pane, and do any of them have exterior shutters that close?"

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