Any nonconforming building or use which has been damaged by fire, explosion, flood, windstorm, or other acts of God shall be considered partially destroyed if the cost of restoration equals 1/2 or less than 1/2 of the estimated true valuation of the building as determined by the Tax Assessor. Such building or use may be rebuilt, restored, or repaired. If the damage is greater than above outlined, the building or use shall be considered completely destroyed and shall not be rebuilt, restored or repaired unless in conformity to the building and use requirements of this chapter.