After the adoption of such zoning regulations or building line regulations by the Board and/or the Council, no building or other structures shall be erected, constructed, enlarged or altered, or repaired in such manner as to prolong the life of the building, nor shall the use of any land be changed without a permit issued in accordance with the rules and regulations adopted by the Council or Board under the terms of this act¹ by the County Inspecting Officer as to territory falling within the jurisdiction of the county and of the Inspector of the municipality as to territory falling within the jurisdiction of the municipality. The County Inspecting Officer shall have the duty of administering the rules and regulations under this act applicable to territory over which the municipality does not have jurisdiction, and shall make such inspections and investigations as may be necessary to the proper enforcement of such rules and regulations. The Inspector of the municipality shall have the duty of administering the rules and regulations under this act insofar as it applies to the territorial jurisdiction of the municipality and shall make such inspections and investigations as may be necessary to the proper enforcement of such rules and regulations, except that in the matter of construction, surfacing and maintenance of streets, roads, and highways in the entire unincorporated area of the county, the Board may prescribe rules and regulations and prescribe standards and the County Engineer shall have the duty of administering such rules and regulations and when requested, shall assist in administering the rules and regulations governing subdivision of land in the unincorporated portions of the county and shall make such inspections and investigations as may be necessary to the proper enforcement of such rules and regulations. The County Inspecting Officer and the City Inspector may be designated as one and the same person by the Board and Council respectively, and when so designated shall exercise the authority vested in both officers.