California Climate Zone 4 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 4 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 4 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 4 is one of them.
Why Climate Zone 4 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.
Cities & areas in Climate Zone 4
Climate zones are assigned by exact project address — often by ZIP code — and a single city can span more than one zone. Rather than publish an unverified city list, we confirm your zone from your project address. Browse our city Title 24 pages or read how cities map to Zone 4.
California Title 24 Climate Zone 4. Your project's zone is set by its address; see the California Energy Commission's official climate zone map for boundaries.
How Zone 4 affects HVAC
The zone's climate influences how heating and cooling are weighted in the model. Current Title 24 favors heat pumps statewide. Zone 4 HVAC requirements →
How Zone 4 affects windows
U-factor and SHGC targets are influenced by the zone's climate. Zone 4 window requirements →
How Zone 4 affects insulation
Wall, roof, and floor performance is measured against the zone's energy budget. Zone 4 insulation requirements →
How Zone 4 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
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