Inspections required under the provisions, rules and regulations adopted by the County Council shall be made by the Department of Land Use. In the case of the inspection of elevators, fuel oil equipment or electric wiring, the Department of Land Use may accept reports of inspectors of casualty companies or of other recognized inspection services after investigation of their qualifications and reliability. Certifications required under the provisions, rules and regulations adopted by the County Council shall be in writing and certified over the signature of the person verifying that the provisions of the New Castle County Building Code are complied with and that there are no unsafe conditions.