Thursday, October 22, 2009

Components of a Washington DC Address

Components of an Address

Addresses shall be parsed into the following component parts and order:

  • Address Number
  • Address Number Suffix
  • Street Name
  • Street Type
  • Quadrant
  • Unit Number

There components of an address are concatenated when creating the address. An example would be 441 GENERIC STREET SE 101.

Address Number

Address numbers, street numbers, are numeric. There shall be no address numbers that are higher than 8500. Fractions, such as "½", are sometimes present, and are always considered address number suffixes.

Address Number Suffix
Fractions (such as '1/2'), as well as alphabetical designations (such as "A') and 'REAR' are not considered address numbers. They are considered address number suffixes. Not all alphabetical designations are to be considered address number suffixes, as some of them are unit numbers.

Street Name

All street names should be spelled out in full in the Master Street Name list. Common aliases for street names, including common abbreviations (e.g., "MLK Ave." for "Martin Luther King Jr. Avenue") are found in the street name alias table. The street name does not include the street type such as 'COURT', 'ROAD or 'STREET.'

Street Type

Street types should be spelled out in full in the in the Master Address Repository. Street Types include, but are not limited to 'ROAD', 'STREET', 'AVENUE', 'COURT' etc.


The quadrants are Northeast (NE), Northwest (NW), Southeast (SE) and Southwest (SW) and shall be abbreviated as shown above. All addresses in Washington DC have a quadrant attached to them (with the possible exception of the Capitol which is at the central point of the addressing grid. These quadrant designations are critical to location of addresses in Washington DC, and must be incorporated into every address.

Unit Number

Unit number denotes a housing occupancy which has a secondary designation. These can be apartments or condominiums


This information as taken from the Master Address Repository (MAR) Address Standards Document (pdf).

Friday, October 16, 2009

Field Research Today

Today, the MAR Data Team is off to do field research (site visits) across a decently large area. We have some interesting sites to visit. Field research is often necessary as sometimes address issues cannot be solved in the office environment. Among the sites are:
  • St. Matthews Court NW & N Street NW
  • 1400 Block of Church Street NW
  • 1500 block of 9th Street NW
  • 1600 block of 11th Street NW
  • New York & 6th Street NW
  • 600 block of I Street NW
  • Union Station Bike Transit Center
  • Alley in Capitol Hill Neighborhood
  • Montello Avenue NE
  • 2100 & 2200 block of 24th Place NE
  • Evarts Street NE
  • 400 block of Rhode Island Avenue NE

Thursday, October 1, 2009

Monthly MAR Report: September 2009

Number of Records:
  • Addresses: 141,781
  • Residential Units: 188,801
  • Aliases: 5,199
  • Street Name Alias: 1,022
  • Intersections: 16,359
  • Block: 15,826
  • Address / SSL Cross Reference Table: 236,838


The new DC GIS 2009 Orthoimage has been searched for changes affecting addresses and streets. Dozens of changes have been made based on the image search. About a dozen site visits remain in cases where changes cannot be confidently determined in the office environment.