Repairs and restoration. Repairs and improvements may be made to a non-conforming building or structure provided that no alterations shall be made, except those required by law or ordinance, unless the building or structure is changed to a conforming or more restricted use; provided that the Planning and Zoning Commission and the Board of Aldermen, in case of evident hardship, may permit an enlargement of a non-conforming use not exceeding fifty percent (50%) of the ground floor area of the building. Nothing in this Article shall be taken to prevent the restoration within one (1) year of a non-conforming building destroyed to the extent of not more than one hundred percent (100%) of its reasonable value by fire, explosion, act of God or public enemy, provided that when such restoration becomes involved in litigation, the time required for such litigation shall not be counted as a part of the one (1) year allowed for reconstruction. Alterations may be made to residences and customary accessory buildings located in the commercial zone even though they are a non-conforming use. Enlargement may not exceed fifty percent (50%) of existing square foot area.