Renewable Energy California sealRenewable Energy CaliforniaHomeowner Energy Program Reference
Public Information Index · Updated July 2026

Home › Programs› Title 24

Title 24 Building Energy Efficiency Standards

California Code of Regulations governing minimum energy-efficiency standards for new and renovated buildings.

Regulation Quick Facts
AdministratorCalifornia Energy Commission (CEC)
AuthorityCalifornia Code of Regulations, Title 24, Part 6
Update cycleEvery three years (2016, 2019, 2022, 2025)
Solar mandate effectiveJanuary 1, 2020 for most new low-rise residential construction
Heat pump mandateNewer code editions favor electric heat pumps over gas appliances in new builds

What Title 24 does

Title 24, Part 6 of the California Code of Regulations — commonly called the Building Energy Efficiency Standards — sets the minimum legal requirements for energy use in new construction and major remodels of residential and nonresidential buildings. The standards cover insulation, windows, lighting, HVAC efficiency, water-heating efficiency, and on-site renewable generation.

The residential solar mandate

The 2019 update of Title 24, effective for permits issued on or after January 1, 2020, requires most new low-rise residential constructionto include a solar photovoltaic system sized to meet the building’s annual electricity demand.

Exemptions exist for:

  • Buildings with insufficient roof area or persistent shading
  • Buildings where the cost-benefit calculation specifically fails the CEC criteria
  • Community shared solar arrangements that offset the building’s usage
  • Buildings located in zones designated by the CEC as exempt

The heat-pump and electrification direction

More recent code editions (the 2022 update, effective January 1, 2023, and the forthcoming 2025 update) lean toward electric heat pumps for space and water heating instead of natural gas appliances in new residential construction. The CEC’s stated objective is to align Title 24 with the state’s greenhouse-gas reduction targets under SB 100.

Applies to new construction, not existing homes

Title 24 is a building code.It applies at permit issuance. An existing home does not become subject to the Title 24 solar mandate simply because the mandate exists — only when undertaking major construction or remodel work that triggers code compliance. Existing homes that voluntarily install solar do so under NEM 3.0 (private market) or through state-administered programs such as DAC-SASH for income-qualified households.

Where to verify

Source: California Code of Regulations, Title 24, Part 6 (Building Energy Efficiency Standards). Standards updated on a three-year cycle by the California Energy Commission. Local building departments enforce the standards at permit issuance. Verify current edition with your local building department before relying on a specific requirement.