Temporary construction trailers and signs not exceeding 100 square feet each in area, advertising the prime contractor, subcontractor(s), architect, financing institution and similar data for the period of construction beginning with the issuance of a Construction Permit and concluding with the issuance of a Certificate of Occupancy, provided said trailer(s) and signs are on the site where the construction is taking place and are not on any existing or proposed street or easement.