The definitive guide to NYC real estate terminology — from ACRIS to Zoning Overlays. Essential reference for attorneys, investors, and property professionals.
Last updated: March 2026 · 9.4M+ properties indexed
Automated City Register Information System — NYC's official database for recorded property documents including deeds, mortgages, liens, and UCC filings. Covers Manhattan, Brooklyn, Queens, and the Bronx.
Borough-Block-Lot — the unique 10-digit identifier for every tax lot in NYC. Format: 1 digit for borough (1=Manhattan, 2=Bronx, 3=Brooklyn, 4=Queens, 5=Staten Island), 5 digits for block, 4 digits for lot.
Building Identification Number — a unique 7-digit number assigned to every building in NYC by the Department of Buildings.
Board of Standards and Appeals — NYC agency that hears appeals and grants variances from the Zoning Resolution.
A DOF classification code that describes the building's use (e.g., A = one-family dwellings, O = offices, R = condos). There are over 150 building class codes.
A document issued by DOB certifying a building's legal use and occupancy type. Required for all buildings constructed after 1938. Can be final (permanent) or temporary.
Department of City Planning — NYC agency responsible for zoning, land use planning, and the PLUTO dataset.
Department of Environmental Protection — manages NYC's water supply, wastewater, and environmental regulations.
Department of Buildings — NYC agency that regulates construction, issues permits, conducts inspections, and enforces building codes. Uses both DOB NOW and BIS systems.
Department of Finance — administers property tax assessments, collects taxes, and manages the annual tax lien sale.
Environmental Control Board (now part of OATH) — administrative tribunal that adjudicates violations from DOB, FDNY, DEP, DSNY, and other agencies. Unpaid ECB fines can become judgment liens.
A lien placed against a property when ECB fines remain unpaid. These liens attach to the property (not the owner) and must be satisfied at closing.
Floor Area Ratio — the ratio of a building's total floor area to the lot area. Determines maximum buildable square footage. A FAR of 2.0 on a 10,000 sq ft lot = 20,000 sq ft maximum.
Housing Preservation & Development — NYC agency that enforces the Housing Maintenance Code, manages emergency repairs, and tracks rent stabilization. Issues Class A, B, and C violations.
Class A = non-hazardous, Class B = hazardous (must be corrected within 30 days), Class C = immediately hazardous (must be corrected within 24 hours). Includes issues like no heat, lead paint, and pests.
A notice filed in court (and recorded in ACRIS) indicating pending litigation affecting a property. Alerts potential buyers to legal claims.
Notice of Property Value — DOF's annual notice to property owners showing the tentative assessed value for the upcoming tax year. Can be challenged through Tax Commission.
Office of Administrative Trials and Hearings — the umbrella agency that now includes ECB. Handles administrative violation hearings for NYC agencies.
Primary Land Use Tax Lot Output — DCP's comprehensive dataset of NYC tax lots with land use, building characteristics, geographic information, and zoning data.
NYC rent regulation system that limits annual rent increases for eligible apartments (generally buildings with 6+ units built before 1974). Status tracked through HPD and DHCR records.
NYC property tax classification: Class 1 (1-3 family homes), Class 2 (apartments/co-ops/condos), Class 3 (utilities), Class 4 (commercial/industrial). Each has different assessment ratios.
NYC's annual sale of liens on properties with unpaid taxes, water/sewer charges, or certain other debts. Buyers can charge interest (up to 18%) and ultimately foreclose.
A written summary of the findings from a title search, including chain of ownership, mortgages, liens, judgments, and encumbrances. RegWatch generates instant comprehensive abstracts from ACRIS data.
The process of examining public records to determine legal ownership of a property and identify any claims, liens, or encumbrances against it.
Uniform Commercial Code filing — a legal form filed to give notice of a security interest in personal property. Recorded in ACRIS and relevant for commercial transactions.
Uniform Land Use Review Procedure — the public review process for proposed changes to land use and zoning in NYC, managed by DCP.
An exception from the Zoning Resolution granted by BSA when strict application would cause unnecessary hardship. More difficult to obtain than a special permit.
A geographic area where specific land use regulations apply. NYC has three basic types: Residential (R), Commercial (C), and Manufacturing (M), each with multiple sub-districts.
An additional layer of zoning regulation applied on top of the underlying zoning district. Examples include flood zones, historic districts, and inclusionary housing areas.
BBL (Borough-Block-Lot) is NYC's unique property identifier. You can find it on your property tax bill, through DOF's property lookup, or by searching any address on RegWatch.
DOB violations relate to building/construction code issues (permits, structural, safety). HPD violations relate to housing maintenance code issues in residential buildings (heat, pests, lead paint).
FAR (Floor Area Ratio) is the maximum ratio of building floor area to lot area. It determines how much you can build on a lot. Higher FAR = more buildable square footage.
Yes. Unpaid ECB fines are docketed as judgment liens that attach to the property and must be satisfied at closing. RegWatch automatically detects these liens.
A C of O is a DOB document certifying a building's legal use and occupancy. It specifies what activities are permitted and how many occupants are allowed.
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