This section applies only to: Calvert County; Caroline County; Dorchester County; Frederick County; Harford County; Kent County; and Worcester County. The provisions of §§ 9–105 and 9–106 of this article apply to an act, an ordinance, or a resolution adopted by a commission county under this section. A building code or housing code adopted under this section does not apply to a building on a farm or to any premises devoted solely to agricultural uses. Notwithstanding paragraph (1) of this subsection, a building code or housing code adopted under this section applies to: in Calvert County, dwellings on which construction is begun after July 1, 1979; or in Frederick County, residential buildings or buildings constructed for human habitation regardless of location or other auxiliary use. The County Commissioners of Kent County shall adopt a building code and a housing code. The governing bodies of Calvert County, Caroline County, Dorchester County, Frederick County, Harford County, and Worcester County may adopt a building code and a housing code. A building code or housing code adopted under this section, and all regulations adopted under the codes, shall be designed to protect the public health and welfare. A building code shall include: regulations requiring a building permit before a building is built or improved; and standards for constructing, maintaining, and repairing, including structural safety, fire prevention, lighting, ventilation, and proper means of access. A housing code shall include regulations and standards for human habitation, including sanitation, density of occupancy, open space, and rodent infestation. A building code or housing code may include provisions for enforcement of the code, including providing for inspectors and penalties for a violation of the code or the regulations adopted under the code. Except as provided in paragraph (2) of this subsection, a building code or housing code adopted under this section may incorporate by reference all or part of a building code or housing code issued or proposed and made available for general distribution by any governmental unit or trade or professional association. In Caroline County, Frederick County, Harford County, Kent County, and Worcester County, any later amendment to a code or part of a code that is adopted by reference is not effective until the governing body of the county incorporates the specific amendment into the county’s building code or housing code. This subsection applies only to: Frederick County; Harford County; and Kent County. The governing body of the county may charge a fee for a zoning certificate or permit for construction of improvements to real property.