If the special exception application is approved by the Board, the applicant shall be entitled to proceed with the submission of a preliminary land development plan to the Township Planning Commission, if appropriate, or complete any erection, construction, reconstruction, alteration or change as authorized. The approval for a special exception will expire if the applicant fails to obtain a zoning permit within six months from the date of authorization by the Board. Upon written application and for reasonable cause, the Board may extend the approval of the specific exception for an additional period of up to one year.