Wednesday, November 24, 2010

Questions Regarding the Residential Units

What is the Residential Unit Table?

The residential unit table contains unit values and other related information regarding residential units. There are estimated 204,000 to 210,000 residential units (with a secondary address).  Each residential unit is associated with an address from the address table (via the ADDRESS_ID field). Example unit values include '101', '201', 'A', '910', '1', '6' and 'A2.' This data includes both rental and condo units which is noted in the 'UNIT_TYPE' field. For condo units the condo's SSL values and condo book and page number is also stored.

What are some of the challenges while creating the Residential Unit Table?

The biggest challenge is just dealing with acquiring the the huge quantity of residential units which is estimated at 204,000 to 210,000. Another challenge is matching the residential unit information with condo units from Office of Tax & Revenue's ITS Public Extract table. Unfortunately, in the ITS Public Extract table there is a tremendous amount of incomplete and incorrect data. This is especially true when it comes to the premise address and unit number columns.

What are the remaining weaknesses in the Residential Unit Table?

• Special use residential facilities (University Dorms, Group Homes, Retirement, Nursing Home and Military Barracks)
• Multi unit row houses
• Large buildings with a low occupancy rate
• Buildings which were constructed very recently

Wednesday, November 17, 2010

Address Fail!

Address Fail!  Where is the digit 4? (from Google Maps StreetView)
 (Click on image for larger version)

Friday, November 12, 2010

Door Removed - Address Retired

In the past there was a door here (red circle). 

The yellow building previously had two housing occupancies and two addresses.  Now, the yellow building has only one occupancy and one address.  The address which represented the occupancy where the door was has now been given a status of 'RETIRE' in the MAR.    If one looks really closely at the image (click on it) then one can see the outline of where the door had been.    Notice that the neighboring buildings both have two doors and the same placement of windows on the second floor.  
Just like our dynamic city, our addresses are also dynamic!

Thursday, November 4, 2010

MAR Monthly Report: October 2010

Dataset Numbers (as of Nov 1st, 2010):

  • Addresses: 142,534
  • Residential Units: 205,321
  • Aliases: 5,697
  • Street Name Aliases: 1,055
  • Intersections: 17,714
  • Blocks: 15,841
  • Address / SSL Cross Reference: 235,514

MAR News:

  • Dorms added as Residential Units on Georgetown University, American University and Wesley Theological Seminary
  • Added new field called ACTIVE_RES_UNIT_COUNT to MAR. This field will show the number of active residential units at each address that are in the residential unit table in the MAR. Now, it is very easy to the AddressPt and select all addresses which have more than 100 apartments.
  • New Condos Records from OwnerPt
  • Updated Marinas in Alias Names
  • Updated Hospital Names
  • Activated over a hundred 'ASSIGNED' or 'TEMPORARY' addresses based on new Google Maps imagery.
  • Continuing to go through the No Match addresses from the County Project with USPS

******* Address Number Suffix vs. Residential Unit Policy Changes *******

There has been ongoing confusion related to the question of what is considered an Address Number Suffix (ANS) and what is considered a Residential Unit (Unit) in Washington, DC. In terms of formatting, an ANS designation would be located between the address number and the street name (example: 302 A 14th Street NE) whereas a Unit would be located after the quadrant designation (example: 302 14th Street NE #A). Currently, there is inconsistency in the Master Address Repository’s (MAR) address database regarding the use of the ANS versus a Unit. After reviewing the United State Postal Service’s established addressing formats and consulting with Department of Consumer and Regulatory Affairs (DCRA), it has been determined that hundreds of these ANS should be considered residential units. By changing these address number suffixes into residential units, the MAR will better reflect reality. These changes will also improve address geocoding.

Going forward here is the policy:

  • All '1/2' designations will be considered as address number suffixes
  • 'REAR' designations which are a separate building will be considered as address number suffixes. 'REAR' designations which are in the same building as the primary non 'REAR' address will be considered units.
  • All letter designations which are not on a separate property and represent one occupancy will be considered units (except for military addresses).
Therefore, over the next month hundreds of addresses which have address number suffixes will be transformed into residential units. These address number suffixes will be deleted from the address table; in their place will be residential units.

The MAR Data Team will be storing a table of those addresses which will be deleted. This table can be used to convert address number suffixes into units or addresses. This will affect about 0.5% of addresses in the MAR.