Notwithstanding any other provision of this Zoning Ordinance and particularly the provisions of Article VIII hereof, any building or structure located in a R-1, R-2 or R-3 zone presently used for residential purposes and lawfully in existence at the effective date of this chapter or one year prior thereto, may be rebuilt in the event of damage, destruction, or intentional demolition without obtaining a variance provided the dimensions of the structure are substantially identical to the dimensions of the damaged, destroyed or demolished structure.