Title 24 requirements apply statewide to permitted projects, enforced by local building departments. They cover:
| Category | Key Requirements |
|---|---|
| Building Envelope | Minimum insulation R-values (e.g., walls R-13 to R-21 by zone), air leakage ≤5 ACH50, cool roofs in hot zones. |
| HVAC | High-efficiency systems (e.g., SEER ≥14 for AC), duct sealing/testing, heat pumps prioritized for heating. |
| Lighting | High-efficacy sources (e.g., LEDs ≥45 lm/W), occupancy sensors, dimmers; separate controls for general/specialty lighting. |
| Water Heating | Electric heat pump water heaters (HPWH) mandatory in new low-rise residential; efficiency ≥2.0 UEF. |
| Renewables | Solar PV required for most new low-rise multifamily and single-family homes (since 2020); battery storage for certain nonresidential. |
| Ventilation | Continuous mechanical ventilation (e.g., ASHRAE 62.2); demand-controlled in commercial spaces. |
Compliance uses CEC-approved software like EnergyPro; reports must be registered via a HERS provider.