California's Title 24 standards include solar photovoltaic requirements for most new construction, with battery-storage provisions for additional building types — applied statewide, including Climate Zone 4.
Solar and storage under Title 24
The 2020 standards introduced a solar PV requirement for most new low-rise residential. The 2022 standards expanded solar and battery-storage provisions to additional building types such as certain multifamily and nonresidential occupancies. 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.
The required PV system size is calculated from your project's address and energy profile, so it reflects Zone 4's solar conditions. Related: what is a Title 24 report?