The

Parcel-Property Connection

Two Datasets and How They Work Together to Support Effective City Services

Parcels

Properties

In Philadelphia, parcels and properties are recorded by separate departments.

A parcel can contain one or more properties.

1000

Walnut Street

Unit A

Unit C

Unit B

Why is it important to know which parcel a property belongs to?

Parcels are the only way to locate a property in the real world.

• Parcels are stored in a geographic database which allows them to be located and mapped.
• Properties are stored without geography, but should keep a reference to the parcel they sit on.
• To place the property on a map, a relationship can be made to the parcel to get its location.

To obtain documents such as deeds

• The Department of Records (DOR) manages real estate documents by parcel ID number.
• Most homeowners are only familiar with their property tax ID, a different number assigned by the Office of Property Assessment (OPA).
• To pull the deed for a property, a connection must be made to its parcel.

Currently, there is no mechanism in place to store the relationship between parcels and properties.

What does this mean for the City?

Custom-built solutions are needed to mitigate differences.

• The Unified Land Record System (ULRS) was developed to integrate property-related data from across City departments that do not share a common identifier.
• The system attempts to match properties to parcels programmatically — but isn't always correct.

Project delays and cost overruns can occur.

• Recent citywide projects have had significant setbacks due to the complicated relationship between parcels and ownership.
• When pointed to ULRS, vendors have cited irreconcilable data issues as barriers to use.
• Some departments have created a from-scratch parcel dataset to reflect true ownership as recorded by OPA.

What can we do to make sure parcels and properties are in sync?

• The OPA mainframe is able to store a parcel number for each property in the system.
• Currently, that field is being used to store the tax account number.
• To ensure a reliable link to parcels, that field could be repopulated with the parcel ID assigned by DOR.
• The tax account number could be migrated to the property ID field, which isn't currently in use.
• If these changes aren't feasible in the current environment, provisions could be made to reference parcels in the forthcoming CAMA system.

Solution #1:

Properties should reference a parcel.

Solution #2:

Parcels should have a unique identifier.

• 5% of DOR parcels have a parcel ID (aka "map registry number") that is not unique.
• This means that OPA cannot leverage parcel IDs without creating ambiguous relationships.
• Uniqueness should be validated at the database level to prevent data entry errors.

Philadelphia has a unique challenge: