Historical or Retired Air Rights Lot polygons. Air right lots are established by RPTA to reflect a party's right to construct an improvement above an existing area of land that is not owned by the constructor. They are a type of development right in real estate referring to the empty space about a property. These tax lot numbers start at 7000. There are approximately 704 air rights lots. Air rights are taxed in DC.Created as part of the DC Geographic Information System (DC GIS) for the D.C. Office of the Chief Technology Officer (OCTO) and participating D.C. government agencies. They are created by the DC Office of Tax and Revenue, Real Property Tax Assessment Office.