Windows are a key Title 24 variable. In Climate Zone 8, the metrics are the same statewide — U-factor and Solar Heat Gain Coefficient (SHGC) — with targets influenced by the zone's climate.
The two key window metrics
- U-factor — how well a window insulates (lower is better)
- SHGC — how much solar heat passes through (lower reduces cooling load)
Title 24 is a statewide California energy code. Climate Zone 8 does not have its own separate rules — the same statewide standards apply, with the energy budget calibrated to this zone's climate. Your project's exact requirements are determined when your specific address is modeled in CEC-approved compliance software. In hotter parts of California, SHGC tends to carry more weight; in cooler areas, U-factor matters more. The exact target for your project is set by modeling your address.