California Climate Zone 9 is one of the 16 official climate zones the California Energy Commission uses to set Title 24 energy budgets. Title 24 is a statewide California energy code. Climate Zone 9 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.
What Climate Zone 9 means
Each of California's 16 zones reflects distinct temperature, humidity, and solar conditions, and each has its own energy budget under Title 24. Climate Zone 9 is one of them.
Why Climate Zone 9 matters for Title 24
Although the standards are statewide, the budget your design must meet is calibrated to the zone — which can shift the emphasis between insulation, HVAC, windows, and solar. The exact targets are determined when your address is modeled.
The Climate in Zone 9 and What It Means for Your Report
Climate Zone 9 covers much of the Los Angeles basin and its inland valleys, including much of Los Angeles as well as Pasadena, Glendale and Burbank, and extends to inland Ventura County cities such as Thousand Oaks and Simi Valley. Summers are hot and long, winters are mild, and the ocean's cooling influence fades the farther a site is from the coast.
Cooling is a major driver of the energy model in Zone 9. Window solar gain, orientation and shading, attic and roof design, and ducts located in hot attics can all push a design over its budget, while an efficient heat pump and well-sealed ducts help bring it back. Heating is a smaller share of the total, so upgrades that reduce summer heat gain usually do more for compliance here than extra winter-focused measures.
Cities & areas in Climate Zone 9
Climate zones are assigned by exact project address — often by ZIP code — and a single city can span more than one zone. The cities named on this page are examples only; we always confirm your zone from your project address. Browse our city Title 24 pages or read how cities map to Zone 9.
California Title 24 Climate Zone 9. Your project's zone is set by its address; see the California Energy Commission's official climate zone map for boundaries.
How Zone 9 affects HVAC
The zone's climate influences how heating and cooling are weighted in the model. Current Title 24 favors heat pumps statewide. Zone 9 HVAC requirements →
How Zone 9 affects windows
U-factor and SHGC targets are influenced by the zone's climate. Zone 9 window requirements →
How Zone 9 affects insulation
Wall, roof, and floor performance is measured against the zone's energy budget. Zone 9 insulation requirements →
How Zone 9 affects solar & heat pumps
Solar PV is required for most new low-rise residential statewide, with PV size set by your project; heat pumps are favored under current code. Solar & battery → · Heat pumps →
Common project types
Looking for a specific address? See every city and ZIP code in Climate Zone 9, taken from the California Energy Commission's official table, or use the climate zone ZIP code lookup.
Title 24 Guides for Climate Zone 9
Begin with the Climate Zone 9 Title 24 requirements overview, then read Zone 9 HVAC requirements, Zone 9 heat pump requirements and Zone 9 window requirements, which reflect the zone's cooling-driven climate. Los Angeles-area ADU projects are covered in the Zone 9 ADU guide, and Title 24 cost in Zone 9 explains pricing. For statewide background, see California Title 24 requirements and Title 24 calculations. City guides include Los Angeles and Pasadena.
Climate zones follow the project address, not just the city name, and one city can straddle two zones. We confirm the exact zone from your address or ZIP code when we model the project; you can also check it yourself with our California climate zone lookup.
Title 24 pricing
- ADU — from $199
- Residential — from $245
- Multifamily — from $345
Standard turnaround: 2–3 business days. Rush (next business day): +$49 ADU / +$99 Residential / +$149 Multifamily. Super Rush (same day — typically completed within a few hours): +$150, subject to availability. Every report includes two revisions. See our pricing page.
What we need
- Architectural plans (PDF)
- Project address (this determines your climate zone)
- Scope of work
- Contact information
- Any plan-check comments (if available)
What we deliver
- Complete Title 24 energy report
- CF1R documentation (LMCC when applicable)
- CHEERS registration completed
- Professionally signed, permit-ready PDF package
- Two Revisions Included