The parcel layer depicts land parcels, or lots, and is a compilation of legal documents, including deeds and plats from the Loudoun County Courthouse. Parcels are used in the assessment process as well as in zoning, planning, and other processes. Every parcel in the layer has a parcel identification number (PIN), which is also referred to as a map, cell, parcel identifier (MCPI). The parcel layer is maintained daily.
The data projection is UTM NAD 1983 Harn, or Universal Transverse Mercator, North American Datum (Virginia North) 1983 High Accuracy Reference Network. This differs from the NAD 27 projection that uses the Clarke 1866 spheroid.
The county has been divided into 701 maps for display and printing purposes. Each map has been subdivided into cells and then numbers to complete the MCPI. Hard copy parcel maps are available at 1:4800 (1 inch equals 400 feet).
For additional information, please contact the Office of Mapping and Geographic Information by calling 703-771-5778.