When a proposed amendment of this chapter involves a change in the zoning classification of 25 or fewer parcels of land, then, in addition to the advertising as above required, notice in accordance with § 15.2-2204 of the Code of Virginia, as amended, shall be given by the Commission at least five days before the hearing to the owner or owners, their agent or the occupant of each parcel involved and to the owners, their agent or the occupant of all abutting property and property affected. In any county or municipality where notice is required under the provisions of this section, notice shall also be given to the owners, their agent or the occupant of all abutting property and property immediately across the street from the property affected which lies in an adjoining county or municipality of the commonwealth. If the hearing is continued, notice shall be remailed. Whenever the notices required hereby are sent by an agency, department or division of the local governing body, such notices may be sent by first class mail; provided, however, that a representative of such agency, department or division shall make affidavit that such mailings have been made and file such affidavit with the papers in the case. Costs of any notice required under this chapter shall be taxed to the applicant.