FAQ (Frequently Asked Questions)

Who can I contact with specific questions about properties or questions about the data?
Rasheed Berry, rasheed.berry@dc.gov 202.442.7102
Matt Crossett, matthew.crossett@dc.gov 202.442.7100    
How can I access the VPM data?
DC Open Data Portal
* Via DC GIS Open Data Real Property search (downloadable data in Shapefiles, KML for GIS applications, and CSV for tables and spreadsheets. API's provide access in REST or GeoJSON for use within applications as direct feeds)
Develop Websites Using GIS Web Services

Custom Applications

What does the word Cadastral mean?
   VPM is referred to a a group of "Cadastral" GIS layers. A cadstral map is a map showing political and property boundaries as well as ownerhip of land. 

Who is repsonsible for VPM data? Is the data current? Who maintains the data?
   OCTO GIS and OTR Maps and Titles (RPTA) are the primary care-taker of the VPM data.  OCTO's primary responsibility is data distribution, project support and mapping of Federal lands. OTR's Maps and Titles group is responsible for data maintenance.
The terms are confusing, is there a document which describes all this terminology?
   Yes, its located at the bottom of the Vector Property Map (VPM) home page. The document is called VPM_Background_v1.4.doc.

In the OwnerPoly layer is there a field which tells me what type of lot each polygon is?
   Yes, its called LOT_TYPE (E.g. "1" in this column means the lot is a Record Lot). See others below
  • 1 - Record Lot
  • 2 - Tax Lot
  • 3 - Air Rights Lot
  • 4 - Reservation
  • 5 - Appropriation
  • 6 - Parcel Lot
I know my SSL (Square, Suffix, Lot), how can i tell what type of lot my property is?
   SSL are 12 characters, first 4 digits are for Square, middle 4 digits are for Suffix, and last 4 digits are for Lot)
  • If Lot is numbered 1-799 it is a Record LotAdministered by DCRA – Office of Surveyor
  • If Lot is numbered 800-1299 it is a Tax Lot – Administered by OTR – Real Property Tax Administration
  • If Lot number is 2000-6999 it is a Condo Lot – Administered by OTR – Real Property Tax Administration - no geography, approved by air rights, record lot or tax lot.
  • If Lot is numbered 7000 or above it is a AirRights Lot – Administered by OTR – Real Property Tax Administration
  • If it begin with “PAR” (followed by parent parcel and child lot) it is a ParcelAdministered by OTR – Real Property Tax Administration.  Ex. PAR 01550018 (PAR 155/18)
  • If it begin with “RES” it is a Reservation  Administered by DCRA – Office of SurveyorEx. RES 00660000 (Reservation 66)
How are new properties created in the District?
  Two methods - via The DCRA's Office of the Surveyor or the Office of Tax and Revenue's Real Property Mapping and Assessment Division.

What were the sources for creating the VPM data?
   Multiple sources including, Subdivision maps, A&T Plat maps, Transfer of Jurisdiction maps, Surveys, Condo documentation, Baist Books etc.

What are the weaknesses of VPM data?
    - Data is not 100% real-time; there is a lag between when a property boundary change get approved by DCRA or OTR and the time it makes it way into VPM data
    - Squares and data are not tied to survey points.  Each square is a free floating entity thus data was "best-fit" to ground level planimetrics
What is the relationship between an address and a piece of property?
   It is a many to many relationship. One SSL (Square, Suffix, Lot) can have multiple addresses located on it.
  This often includes garden style apartment complexes as well as corner addresses with separate addresses facing each adjacent street. One address can also sit upon multiple properties. One single family residence can sit upon multiple lots. The address records only contain one "base" SSL (usually from OwnerPLY). the cross reference table contains the many to many relationship between Address ID and SSL. Some addresses do not have an associated SSL (many addresses on Federal properties).

 I work for the private sector and I'm looking for an application that displays the Property Scans - is this Vector Property Map?
   No, but we have data that you can overlay on the Property Scans. Go to DC Atlas Plus and click on DC Atlas (Detailed Online Mapping), DC Atlas All In One Service.  Property Scans (historic) are stored under Aerial  Photography and Scanned Maps, Vector Property data is under Property and Land
Is the GIS data considered legal field survey?
    No, all field surveys must still be approved via DCRA's Office of the Surveyor. The VPM data IS NOT A LEGAL SURVEY! It is an representation of property boundaries but should not be used for property line disputes. A licensed land surveyor is the only legal way of determining property boundaries. The VPM data in most cases will never be as accurate as a legal survey, it is simply impossible to maintain a dataset at that accuracy when you have over 180,000 properties city-wide and only ~7% have been field surveyed.
Furthermore, cadastral maps provide an approximation of property location for taxing purposes. A land survey provides a legal document that is admissible in court. For boundary disputes questions/issues, individuals should contact DCRA's Office of Surveyor.

How do i obtain a legal plat of my land?
   Depending on your needs you could obtain a deed through the The Office of Tax and Revenue GIS and Mapping Services, Recorder of Deeds or a Subdivision Plat/Assessment and Taxation plat at DCRA's Office of the Surveryor Surveyor Services via the Surveyors Document Management System available via publicly accessible kiosk's.

It appears that my property boundaries and surrounding property boundaries are not aligning with the building(s), is this normal?
  No. Its due to the fact that each Square is "best-fit" to ground level physical features (ie curb, sidewalk, building footprints), there is no control points (xy) for squares to tie them to real world coordinates.  We confess that improvements can be made, if you think your square/lot's placement   can be "better fit" please send and email to Rasheed Berry, rasheed.berry@dc.gov with your address or SSL.

 Who is DC's State Cadastral Coordinator for NSGIC?
  Matt Crossett, matthew.crossett@dc.gov 202.442.7100