California Climate Zone 2 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 2 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 2 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 2 is one of them.
Why Climate Zone 2 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 2 and What It Means for Your Report
Climate Zone 2 takes in the inland valleys behind California's north coast, including Santa Rosa, Napa and Petaluma. It sits between the foggy coast and the hot interior: summers are warm and dry, and winters are cool enough that heating remains a real load. Homes here need to handle both seasons rather than just one.
Because both heating and cooling count, the energy model looks at the whole building rather than a single system. Insulation and air sealing reduce winter losses, window selection and shading manage summer sun, and the efficiency of the heat pump or other HVAC system, plus duct location and sealing, affects both seasons. Designs that balance these usually comply more easily than designs that lean on one strong feature.
Cities & areas in Climate Zone 2
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 2.
California Title 24 Climate Zone 2. Your project's zone is set by its address; see the California Energy Commission's official climate zone map for boundaries.
How Zone 2 affects HVAC
The zone's climate influences how heating and cooling are weighted in the model. Current Title 24 favors heat pumps statewide. Zone 2 HVAC requirements →
How Zone 2 affects windows
U-factor and SHGC targets are influenced by the zone's climate. Zone 2 window requirements →
How Zone 2 affects insulation
Wall, roof, and floor performance is measured against the zone's energy budget. Zone 2 insulation requirements →
How Zone 2 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 2, taken from the California Energy Commission's official table, or use the climate zone ZIP code lookup.
Title 24 Guides for Climate Zone 2
The Climate Zone 2 Title 24 requirements page is the natural starting point. From there, read about Zone 2 HVAC requirements, windows in Zone 2 and Zone 2 insulation, which together carry most of the weight in a mixed climate. The Zone 2 ADU guide and the Zone 2 new home guide cover the most common project types, and Title 24 cost in Zone 2 explains pricing. For background, see California Title 24 requirements and Title 24 calculations, and see our Santa Rosa and Napa city guides.
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