Double-Pane Windows
Windows with two layers of glass separated by a sealed air space, providing better insulation than single-pane windows.
Why It Matters for Homeowners
Why it matters: double-pane is the modern standard in California and what Title 24 effectively requires. The two panes trap an inert gas layer (argon is most common) that resists heat transfer far better than air. The failure mode to watch for is a broken seal: moisture between the panes shows up as fogging or condensation on the inside surface that you cannot wipe off. Once the seal fails, the unit cannot be repaired, only replaced.
Related searches: double pane windows, dual pane, insulated glass