A temporary permit may be authorized by the Zoning Hearing Board as a special exception for a nonconforming structure or use which it deems beneficial to promote the proper development of the community, provided that such nonconforming structure or use shall be completely removed upon expiration of the permit without cost to the Township. Such a permit shall be issued for a specified period of time not exceeding six calendar months and may be renewed for an aggregate period of not more than two years.