Any nonconforming use or structure damaged by fire casualty or act of God may be repaired and used as before, provided that the floor area or building area of such use, building or structure shall not exceed the floor area or building volume which existed prior to such damage. All repairs shall be completed within one year after damages occur or such use shall not be rebuilt except as a conforming use. In the event that total destruction occurs or the Zoning Officer orders said use or structure rebuilt, then the provisions of this chapter shall apply.