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, written notice shall be given at least five days before the hearing to the owner or owners, their agent or the occupant of each parcel involved, to the owners, their agent or the occupant of all abutting property and property immediately across the street or road from the property affected, and, if any portion of the affected property is within a planned unit development, then to such incorporated property owners' association within the planned unit development that has members owning property located within 2,000 feet of the affected property. Notice shall also be given to the owner, the owner's agent or the occupant of all abutting property and property immediately across the street from the property affected which lies in Rockbridge County. Notice sent by registered or certified mail to the last known address of such owner as shown on the current real estate tax assessment records shall be deemed adequate compliance with this requirement. If the hearing is continued, notice shall be remailed.