New York City Subterranean Lot Records from the Digital Tax Map

New York City's Department of Finance provides a monthly updated dataset of subterranean lots as part of its official Digital Tax Map collection. Data is extracted from the DOF's internal system on the last Friday of each month and refreshed on ArcGIS Online on the first of the following month. The dataset is provided for informational purposes and may not reflect the latest changes in other city systems.

Use Cases

• Mapping subsurface property boundaries based on the official Digital Tax Map.
• Tracking changes to subterranean lots over time based on the Digital Alteration Book (DAB) log.
• Integrating subterranean lot data with other city property systems for comprehensive analysis.
• Verifying the official status of subterranean lots for legal or development purposes.

Strengths

• Data is updated monthly with a documented extraction and refresh schedule.
• Part of an official city collection (Digital Tax Map) maintained by the Department of Finance.
• A backup system (alternating Set A and Set B) is in place to ensure data reliability.

Limitations

• Description metadata is limited; actual data quality requires manual inspection after download.
• Column-level documentation is absent; field semantics must be inferred after download.
• The data may not reflect the latest changes in other city systems, such as exemptions or buildings data.

Provenance

Source

City of New York, Department of Finance

Collection Method

Extracted from DOF's internal system, published via ArcGIS Online Feature Servers.

Freshness

Monthly updates, last documented update 2026-03-22.

Geography

New York City, New York, USA