An apparatus for a vehicle body including a rocker insert is provided. The apparatus includes a vehicle body including a plurality of metallic structure members and a lower portion operable to provide support to a floor surface within a passenger compartment of a vehicle and a rocker insert mounted to an in-vehicle side portion of the lower portion. The rocker insert includes an elongated bar portion including a hollow center portion including internal reinforcing web features. The rocker insert is oriented with respect to the vehicle body such that a longitudinal axis of the elongated bar portion of the rocker insert is parallel to an in-vehicle forward direction of the vehicle body.