Confirm and size a new-construction residential solar (and possibly storage) system to satisfy California Title 24 Part 6 solar mandate compliance

Steps

1. Confirm which Title 24 Energy Code cycle applies to the permit date — the 2025 Energy Code took effect January 1, 2026 and governs permits issued from that date forward
2. For single-family homes and low-rise multifamily (up to 3 stories), confirm a PV system is required sized to offset the building's expected annual electricity use, based on floor area, orientation, climate zone, and the building's other efficiency measures
3. For commercial, high-rise residential, and other covered nonresidential building types, confirm both solar PV and battery storage are required per the expanded 2023-cycle scope, sized to conditioned floor area and building type
4. If a battery is being added, apply the documented storage credit: installing 7.5 kWh or more allows a 25% reduction in the otherwise-required PV system size
5. Verify roofing material meets the code's thermal emittance / 3-year aged reflectance / Solar Reflectance Index (SRI) requirements for new construction and re-roofing, since these interact with the same code section
6. Route final sizing calculations through the project's Title 24 energy consultant/CF1R compliance documentation rather than estimating informally