Va. Code § 15.2-750
The board, in addition to any other zoning powers granted by general or special law, may include a provision for the dedication of density or other rights to develop real property, as defined by the locality, from one or more parcels of property that are not the subject of a development application and are located in the locality to one or more parcels of property that are the subject of a development application and are located elsewhere in the locality. Such dedication shall be subject to such terms as may be provided by zoning regulations, the conditions of a special use permit or special exception, or the proffered conditions of a rezoning application, including that the terms are binding on the owners of such property and on their successors and assigns.
Va. Code § 15.2-750