Damage Or Destruction. In the event that any non-conforming structure is damaged or destroyed, by any means, to the extent of more than fifty percent (50%) of its structural value prior to such destruction, such structure shall not be restored except in full conformance with the regulations for the zoning district in which is located. In the event that any non-conforming structure is damaged to the extent of fifty percent (50%) or less, no repairs or restoration shall be made unless a building permit is obtained with nine (9) months, and restoration is begun within twelve (12) months after the date of such partial destruction and completion is diligently pursued. The determination of the reduced structural valuation shall be made by the City.