HB 3314 establishes energy efficiency performance standards for residential construction by amending the Health and Safety Code. The bill sets specific insulation and air-sealing requirements for unvented attic and rafter assemblies, mandating that local jurisdictions recognize compliance if certain R-values and air-tightness measures are met. It also requires buildings to attain a specified blower door test result, include mechanical ventilation that does not rely solely on negative pressure, and ensure HVAC equipment and ductwork remain within the building’s thermal envelope.