The Vector Property data was developed with the oversight of the Office of Chief Technology Officer (OCTO) - DC GIS, Department of Consumer of Regulatory Affairs (DCRA) - Office of the Surveyor (OS), and Office of Tax and Revenue (OTR) - Real Property Tax Administration (RPTA). This effort was undertaken with 2 primary goals:
- Support and improve the daily business processes of the two DC agencies that originate and manage land record in the District of Columbia.
- Provide important GIS base layers which will be used extensively by many DC government agencies and private companies.
Below are the responsibilities which DC agencies have provided throughout the Vector Property data creation and maintenance application lifecycle.
Office of the Surveyor- subject matter expertise, provides access and understanding of source documents, extensive resource support, and assists with Vector Property GDB and Maintenance requirements.
RPTA- subject matter expertise, provides access and understanding of source documents, extensive resource and IT support, and assists with Vector Property GDB and Maintenance requirements.
OCTO- Assists with Geodatabase and Maintenance requirements, QC and Program Management staffing. Vector Property database and Citrix Support. Project oversight.
Squares (point, line, poly) - SquaresPT, SquaresLN, SquaresPLY
Squares are calculated by the outer extents of the record or tax lots within a defined area (typically a city block). There are roughly 4867 active squares. A Square is similar to a city block. Squares are numbered starting at 1 and are currently in the 6000 series.
Not all squares are active. A common cause of inactive squares is through street closing and combining squares. When the squares are combined, usually the lower square number is killed and the higher square number is used for the combined square.
Record Lots (point, line, poly) - RecordLotsPT, RecordLotsLN, RecordLotsPLY
Record lots are defined by the Department of Consumer of Regulatory Affairs (DCRA) - Office of the Surveyor (OS) - DC Surveyor. They are official, platted, and recorded subdivision lots created "by" the....."(must have public street frontage, be at least 30ft wide etc). Typically, these lots are numbered 1 through 799 with no number being used more than one time in a Square. There are a few exceptions to this rule. When 1-799 has been exhausted within a square, the Surveyor's Office assigns numbers from 1200 or may even use 8000 and above.
Additionally, in most case scenario's, a piece of property must be a Record Lot before a building permit will be issued for that site in the District of Columbia, and all proposed Record Lots are carefully reviewed by Zoning Administration officials for compliance with the city's Zoning Ordinances. Other agencies that review new record lots besides the Office of the Surveyor are Office of Zoning, Office of Planning, the Department of Public Works, Historic Preservation and District Department of Transportation. Record lots are defined only when requested by property owners, normally when they are seeking a building permit.
Record lots are recorded in Plat Books and Subdivision Books in the Office of the Surveyor. These documents are bound volumes of historical representations of the locations of property lines, and they include record dimensions, though typically no bearings of lines. There are roughly 149,000 active record lots. These lots are located within squares, which usually correspond to one or two city blocks.
Tax Lots (point, line, poly) - TaxLotsPT, TaxLotsLN, TaxLotsPLY
RPTA defines assessment and taxation lots, often referred to as A &T lots or simply tax lots. These lots are strictly for real estate taxation purposes. RPTA normally defines tax lots under two circumstances: 1) when property owners request for their real property tax bills to be consolidated because they have several contiguous lots and want one tax bill or if an alley/street has been closed and the owner wants the residual portion that abuts their lot (this is called a combine); and 2) when part of a record lot is sold, but no new record lot is yet defined (this is called a split request).
There are roughly 31,000 tax lots. Tax lots are not determined by survey, and are therefore not official lots. These lots are normally numbered between 800 and 1999 within a square to differentiate them from record lots on the tax maps. When a tax lot is established by RPTA, an A &T Plat is generated by RPTA and forwarded to the surveyor's office. These A & T Plats are not reviewed but simply filed by the Surveyor; they do not comply with the standards required of subdivision plats.
Tax Lots are not normally acceptable when applying for building permits and must be converted to Record Lots through the normal subdivision process involving the D.C. Surveyor's Office before permits will be issued. The only exception is if the lot does not face a public street.
Furthermore, at the time of their creation and platting, there is no review made of tax lots for compliance with D.C. Zoning, Subdivisions, or any other ordinances. These lots are simply pieces of property, owned by somebody, described in deeds, for which tax bills are sent and real estate taxes are collected by the city. Some Record Lots also function in this capacity.
In addition to the previously described tax lots, there are two special types of tax lots: condo lots and air right lots.
1.) Condo Lots (Normalized tables) - CondoRelate, CondoOneToMany, and CondoRegime
Condo lots are individual lots for each condominium. The lot numbers normally range from 2000-6999. These condo lots are not geographically defined other than being within a air rights, record, tax or a combination of lots that has one or more condo buildings within it. A condo regime number is assigned to each residential Condo application or Article of Confederation regardless of how many buildings there are at any one site. The Regime number starts with a 1, 2, or 3 depending upon where the condo is located and where they fall in the tri-annual assessment process of RPTA. All numbers after the first are consecutive. RPTA maintains the master list of Regime numbers for residential properties. Commerical condos are not associated with a Regime number and in order to properly track all condos, a unique Regime number was created. RPTA then establishes individual accounts for each condominium unit and assigns a condo lot number to that account. RPTA maintains the master list of Regime numbers and there relationship to approved condos. As of March 1, 2010, there are roughly 60,481 condo lots and there associations are as follows: 44530 condos were approved for record lots, 14720 were approved for tax lots, 2254 were approved for air rights lots, and 2050 were approved for both air rights and tax lots.
2.) Air Rights Lots (point, line, poly) - AirRightsLotsPT, AirRightsLotsLN, AirRightsLotsPLY
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. These tax lot numbers start at 7000. There are approximately 60 of these air rights lots. Air rights are taxed in DC.
Geographically, tax lots typically overlay layers such as record lots or sometimes reservations. There are known instances where tax lots do not overlay these types of layers. Up until approximately 1972, A and T lots were only created by the Tax Assessor out of lands that had been previously Record Lots at some point in there history. For a short period of time in the early to mid 1970's, a decision was made to start eliminating fractional parcels (see definition below) and make them all into A and T lots. The intent was to do away with Parcels altogether and have all properties in the city be either tax lots or record lots. By doing this, they converted unsubdivided parcels into A and T lots though no underlying record lot exists. There is often little or no historical source information about there types of transactions therefore vectorizing them often required vast amounts of research. There are approximately 234 of these air rights lots.
Record Lot "Of Lots"
An "of-lot" is the D.C. Surveyor's Office term for describing "Remaining Part of Original Lot X" In the record lot feature class (described earlier), if a domain value of 1 resides in the "OF_LOT" field, you can assume that at one time the original lot was modified. Typically, any of these of-lots will also have a tax lot overlapping them since it is a piece or remainder of a Record Lot. There are approximately 11,000 "of-lots".
Once a record lot has had anything added to it or subtracted to it by deed, both it an all its various pieces receive tax assessors A&T lot numbers. It does not cease being an official Record Lot, however, when it also becomes a Tax Lot. It will carry dual lot numbers thereafter. Only when it is subdivided into a new Record Lot will the old record lot cease to exist.
Parcels (point, line, poly) - ParcelsLotsPT, ParcelsLotsLN, ParcelsLotsPLY
There is still land within the District of Columbia that has never been subdivided into either Record or Tax Lots through the two offices that manage land records (OS & RPTA). This land is referred to as Parcels, expressed as fractions (Ex Parcel 117/36). In this example, the number "36" would be the 36th outconveyance from original Parcel 117.
The tracking of parcels was started in 1905 when, by an Act of Congress, all the District's unsubdivided properties, which were mostly rural farms at the time, were given parcel numbers. Their boundaries were also depicted (in many cases approximated) in large books in OS. Until the late 1960s, building permits were routinely issued by the city for new construction on Parcels. But, today all Parcels, like Tax Lots, must be converted into subdivision Lots of Record before permits will be issued for exterior work.
Parcels are only found in the old "County of Washington," north of Florida Ave and east of the Anacostia River. There are no Parcels found within the original city limits or Georgetown.
** Parcels are not in Squares. There are examples where parcel land may be physically located in the middle of a city Square, but Parcels are not considered part of a Square until they are duly subdivided by the D.C. Surveyor's Office. There are approximately 1263 of these parcel lots.
* This data layer is not finalized; efforts are underway to complete.
Alleys (line, ply) - AlleyLN, AlleyPLY
Alley widths/ street frontages were captured during the vector property effort and reside in their own feature class. 99% of the time, these features should be coincident with the square boundary. The exceptions to this are internal alley's that might be overlaid by a tax lot. They were captured largely to enable continuity within each square. Alley Polygon does not exist.
Building Restriction Lines (line) - BuildingRestrictionsLN
These are lines beyond which property owners or others have no legal or vested rights to extend a building or any part thereof without approval of the proper authorities; ordinarily a line of demarcation between public and private property, but also applied to a building restriction line, when recorded in the records of the Surveyor.
**These features were captured only if they appeared on subdivision plats of active record lots. It is known that not all building restriction lines were capture during this effort.
Highway Planning Lines (line) - HighwayPlanLN
There are lines that occurred on the city's 1901-1905 set of master plans for all proposed roads. If a highway planning line crosses a particular property, that land cannot become a Record Lot by subdivision, even if the proposed street is no longer needed or will never be built. However there is a procedure through which a proposed road can be removed from the Highway Plan freeing up affected land for subdivision or development.
**These features were captured only if they appeared on subdivision plats of active record lots. It is known that not all highway planning lines were captured during this effort and their accuracy can not be verified.
Public Easements (lines) - PublicEasementsLN
These are not to be confused with utility or private easements. They are often placed after an alley closing for traffic or access.
**These features were captured only if they occurred on subdivision plats of active record lots. It is known that very few of these were captured during this effort and their accuracy can not be verified.
Square-Suffix-Lot number (SSL) - Each lot of land is identified by Square-Suffix-Lot number (SSL) as described below:
Suffix can be one of the N (North), S (South), E (East), or W (West) letters referring to directions. Most squares do not have suffixes. However, small areas near other squares were given the same number as the nearby square with a suffix. For example a small land south of square 6002 was identified as square 6002S. Although these squares use a number from a nearby square, they have no dependencies on other squares and can have RL and TL of their own. The suffix is also used to identify parcels. See the previous paragraph on Parcels.
Lot numbers start from 1 for record lots (800 for A&T lots, 2000 for condo lots, and 7000 for air right lots) in each square. When a lot number is killed it is never used again in that square. There are rare occurrences of existing duplicated Record Lots numbers within a square. ITS uses unique Tax Lot numbers for each in order to uniquely identify them.
-Despite the fact that Lot numbers "800 and up" are reserved for use by the Tax Assessor, there are known recorded Subdivision Plats that create Record Lots numbered in the 800s.
- Even though Lot numbers are supposedly never duplicated within a Square, there are numerous instances of this occurring on early plats.
- There are also examples of Tax Lots being numbered lower than 800
- In most case scenarios, condo's lots should only occur and have been built on records lots. There are several exceptions to this statement where condo's were erected on Air Rights and Tax Lots.
Tax Lot/Record Lot Precedence Rules:
Tax Lots and Record Lots are the primary means to identify property within the District. Frequently, both may occupy the same area. However, these are two different entities with different Lot numbers and administered by different DC Agencies. Confusion occurs in determining which Lot is to take precedence when selection of a given property lot is required.
As a rule, Tax Lots will take precedence over Record Lots when both are present for a given address.
The Lot Precedence Rules for a given address are:
1) If a Record Lot Exists, but no Tax Lot, use the existing Record Lot
2) If a Tax Lot Exists, but no Record Lot, use the existing Tax Lot
3) If both a Record Lot and a Tax Lot exist, use the Tax Lot
4) If neither Record Lots or Tax Lots exist,
a. If a Parcel exists, use the Parcel designation
b. If a Reservation exists, use the Reservation designation
c. If an Appropriation exists, use the Appropriation