California Title 24 Window Requirements for Orange County Homeowners
Under California's Title 24 energy code, replacement windows in Orange County generally need a U-factor of 0.30 or lower and a solar heat gain coefficient (SHGC) of 0.23 or lower. Smaller projects (75 square feet of glass or less) have slightly relaxed limits, and patio doors that are more than 25% glass follow the same rules as windows.
The key numbers
| Rating | Requirement (typical OC project) | What it means |
|---|---|---|
| U-factor | 0.30 or lower | How well the window insulates — lower is better |
| SHGC | 0.23 or lower | How much solar heat gets through — lower keeps rooms cooler |
| Small alterations (≤75 sq ft) | U ≤ 0.40, SHGC ≤ 0.35 | Relaxed limits for replacing just a few windows |
Where to find the ratings
Every compliant window has an NFRC label on the glass showing its U-factor, SHGC and visible transmittance. Keep it on until the final inspection if your city requires a permit.
Fire hazard zones
In hillside and canyon areas designated as fire hazard severity zones — parts of Laguna Beach, Trabuco Canyon, Coto de Caza, Anaheim Hills, Yorba Linda and Brea among them — California's wildland-urban interface rules can also require dual-pane windows with at least one tempered pane.
Do you need a permit?
Permit requirements vary by city and by the scope of the job. Changing an opening size almost always requires one. We confirm the rules for your city before work starts and handle permits where they're required.
Last updated November 2026 · Prices are typical installed ranges, not quotes.
Frequently Asked Questions
Do Title 24 rules apply if I'm only replacing one window?
Yes, but replacements totaling 75 square feet of glass or less are held to the relaxed limits shown above.
Are the replacement windows you install Title 24 compliant?
Yes. Every window and glass patio door we quote meets the current California energy code for your home's climate zone.
Ready for new windows or doors?
Free in-home estimates across Orange County · Mon–Sat 9:00 AM – 5:00 PM