Any county plan may include planning of incorporated towns to the extent to which, in the county local planning commission's judgment, it is related to planning of the unincorporated territory of the county as a whole. However, the plan shall not be considered as a comprehensive plan for any incorporated town unless recommended by the town commission, if any, and adopted by the governing body of the town.
Any municipal plan may include the planning of adjacent unincorporated territory to the extent to which, in the municipal local planning commission's judgment, it is related to the planning of the incorporated territory of the municipality. However, the plan shall not be considered as a comprehensive plan for such unincorporated territory unless recommended by the county commission and approved and adopted by the governing body of the county.
Va. Code § 15.2-2231