Substantial damage or destruction. In the event that any nonconforming structure or use is substantially damaged or destroyed, by any means other than demolition, to the extent of more than 50% of the cost of replacement of such structure new, proof should be supplied by the applicant in written estimate form of replacement value and work to be done by a minimum of two reputable agencies. Such structure shall not be restored unless, if within 30 days after the substantial damage, the owner of said nonconforming use notifies the Zoning Administrator, in writing, of his intent to restore said nonconforming use substantially to the conditions existing prior to the disaster. It is the owner's responsibility to provide documentation of existing nonconforming conditions prior to the disaster to satisfy the Zoning Administrator. In that instance, the Zoning Administrator shall permit the issuance of a building permit within 30 days of receipt of the written notice of intent for such substantial restoration without further action. Restoration under this section shall be commenced within six months of the date of issuance of a building permit, and restoration shall be completed within one year of the issuance of the building permit. In the event that the Zoning Administrator is not notified of the intent to restore the nonconforming use within the time limit stated, such structure shall not be restored unless the structure and use thereof shall conform to all current regulations of this chapter.