California Climate Zone 3 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 3 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 3 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 3 is one of them.
Why Climate Zone 3 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 3 and What It Means for Your Report
Climate Zone 3 follows the central coast and the Bay Area shoreline, including San Francisco, Oakland and Berkeley. Ocean air keeps it mild all year: summers are cool, winters are rarely severe, and many older homes were built without air conditioning at all.
With modest heating and very little cooling, the energy budget in Zone 3 is comparatively small, so every system counts. Heating efficiency and a tight, well-insulated envelope usually matter more than cooling. Water heating makes up a larger share of total energy use than it does in hot inland zones, which is why heat pump water heaters often help a design comply. Windows still matter, but mainly for heat loss rather than solar gain.
Cities & areas in Climate Zone 3
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 3.
California Title 24 Climate Zone 3. Your project's zone is set by its address; see the California Energy Commission's official climate zone map for boundaries.
How Zone 3 affects HVAC
The zone's climate influences how heating and cooling are weighted in the model. Current Title 24 favors heat pumps statewide. Zone 3 HVAC requirements →
How Zone 3 affects windows
U-factor and SHGC targets are influenced by the zone's climate. Zone 3 window requirements →
How Zone 3 affects insulation
Wall, roof, and floor performance is measured against the zone's energy budget. Zone 3 insulation requirements →
How Zone 3 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 3, taken from the California Energy Commission's official table, or use the climate zone ZIP code lookup.
Title 24 Guides for Climate Zone 3
Begin with the Climate Zone 3 Title 24 requirements overview. Because heating and water heating dominate here, the Zone 3 heat pump guide and Zone 3 insulation requirements are the next reads, followed by Zone 3 window requirements. Bay Area homeowners adding a backyard unit can use the Zone 3 ADU guide, and Title 24 cost in Zone 3 covers pricing. For the statewide rules, see California Title 24 requirements and how the energy calculations work. City guides for this zone include San Francisco and Oakland.
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