In all Commercial Districts, the level of a yard or of a rear yard equivalent shall not be higher than curb level. However, this Section shall not be construed to require that natural grade level be disturbed in order to comply with this requirement.

No building or other structure shall be erected above ground level in any required yard or rear yard equivalent except as otherwise provided in Section 33-23 (Permitted Obstructions in Required Yards or Rear Yard Equivalents).