Data Glossary

A property report pulls together records from dozens of public sources. Here's what each field means in plain English — including which values are good or worth a second look.

Identifiers

BBL

Borough-Block-Lot: NYC's unique 10-digit tax-lot ID for a parcel of land.

Why it matters: It's the key that ties together every city record for this property — tax, deeds, violations, zoning.

BIN

Building Identification Number: NYC's unique 7-digit ID for a specific building.

Why it matters: A single lot (BBL) can hold several buildings; the BIN pins records to one of them.

Block

The tax block number — the middle segment of the BBL. NYC groups lots into numbered blocks.

Lot

The tax lot number — the last segment of the BBL, identifying this individual parcel within its block.

Building

Building Class

NYC Dept. of Finance building-class code describing the structure type (decoded inline).

Why it matters: Tells you what kind of building it is — e.g. a one-family home, a walk-up, an elevator co-op.

Landmark

Whether the building is an individually designated NYC landmark.

Why it matters: Landmark status restricts exterior changes — renovations need Landmarks Preservation Commission approval.

Owner Type

Who owns the lot, by category.

C
City ownership.
M
Mixed city/private ownership.
O
Other public (state, federal, or public authority).
P
Private (an individual, company, or non-profit) — or fully tax-exempt private.
X
Fully tax-exempt, city/state/federal owned.
Land Use

The lot's broad land-use category (NYC City Planning code).

10
Parking facilities.
11
Vacant land.
01
One- & two-family buildings.
02
Multi-family walk-up buildings.
03
Multi-family elevator buildings.
04
Mixed residential & commercial.
05
Commercial & office buildings.
06
Industrial & manufacturing.
07
Transportation & utility.
08
Public facilities & institutions.
09
Open space & outdoor recreation.

Zoning & Land Use

Zoning District

The NYC zoning district code governing what can be built and how it can be used.

Why it matters: R = residential, C = commercial, M = manufacturing, plus a density number. Determines allowed uses, size, and height.

Built FAR

Floor Area Ratio actually used: building floor area ÷ lot area.

Why it matters: Compare to Max FAR — a big gap means unused development rights (air rights) may exist.

Max FAR

The maximum Floor Area Ratio zoning allows on this lot.

Why it matters: Caps how much building is permitted; Built FAR below this suggests room to expand or sell air rights.

Residential FAR

Maximum Floor Area Ratio allowed for residential use on this lot.

Commercial Overlay

A commercial (C1/C2) overlay mapped onto a residential district, allowing local retail on the ground floor.

Special District

A special-purpose zoning district with its own extra rules (e.g. a waterfront, downtown, or historic special district).

Split Zone

Whether the lot straddles two or more zoning districts.

Why it matters: A split lot follows different rules on different parts, which complicates what can be built where.

Flood & Environment

Flood Zone

FEMA flood-risk zone for the property.

Why it matters: High-risk zones (A/AE/V/VE) usually require flood insurance and signal real flooding risk.

X
Minimal risk — outside the 100- and 500-year floodplains. No mandatory flood insurance.
AE
High risk (1%/yr chance) with a known base flood elevation. Flood insurance typically required.
A
High risk (1%/yr chance), no base flood elevation determined.
AO
High risk from shallow sheet-flow flooding (usually 1–3 ft).
VE
High risk coastal zone with wave action — the most hazardous, insurance required.
V
High risk coastal zone with wave action, no base flood elevation determined.
UNKNOWN
No FEMA flood-zone data was returned for this point.

Safety & Violations

Material

What the drinking-water service line is made of.

Why it matters: Lead or galvanized (or unconfirmed) lines are a health and replacement-cost concern.

Lead
Confirmed lead service line — a health hazard; replacement is costly.
Non-Lead
Confirmed not lead (e.g. copper or plastic).
Galvanized Service Line Requiring Replacement
Galvanized pipe downstream of a lead line — treated as lead-equivalent.
Unknown - Lead Status Unknown
The city hasn't confirmed the material — treat as possible lead.
Non-Applicable
No service-line record applies to this lot.
Open DOB Violations

Open violations from the NYC Department of Buildings (DOB), which enforces construction & building-safety rules.

Why it matters: Open violations are unresolved liabilities a buyer inherits; 0 is best.

Total DOB Violations

All-time count of NYC Department of Buildings violations on record for the building.

Open HMC Violations

Open Housing Maintenance Code violations (heat, hot water, pests, upkeep) issued by NYC's housing agency, HPD.

Why it matters: Signals landlord neglect / deferred maintenance; 0 is best.

Open Class C (Immediately Hazardous)

Open Class C Housing Maintenance Code violations — the most serious, 'immediately hazardous' tier.

Why it matters: Class C means dangerous conditions (no heat, lead paint, mold). Any open Class C is a red flag.

ECB Fines

Unpaid fines from ECB/OATH summonses — the NYC tribunal that adjudicates building & quality-of-life violations.

Why it matters: Outstanding fines can attach to the property; lower is better.

Severity

Hazard grade of the housing violation.

A
Non-hazardous (e.g. a minor upkeep issue).
B
Hazardous (must be fixed reasonably promptly).
C
Immediately hazardous — the most serious (no heat, lead paint, mold, vermin).
I
Informational only.
Rent-Impairing

A 'Y' flag marks a rent-impairing violation: tenants may legally withhold rent until it's fixed.

Legal & Ownership

Ownership % Transferred

Share of ownership conveyed by a deed.

Why it matters: 100% is a full transfer; less than 100% is a partial-interest transfer (e.g. between co-owners).

Document Type

The kind of legal document recorded (deed, mortgage, lien, etc.).

Tax Class

NYC property tax class (1–4) that sets how the property is assessed and taxed.

1
Mostly 1–3 family homes.
2
Other residential (co-ops, condos, rentals).
3
Utility property.
4
Commercial and industrial.
Market Value

The CITY's estimated market value used for tax assessment — often well below the actual sale price. Not an appraisal.

Why it matters: Don't mistake it for what the home is worth; it's a tax figure the NYC Finance Dept. calculates.

Assessed Value

The taxable assessed value the city applies its tax rate to (a fraction of market value).

Assessed Land Value

The taxable assessed value of just the land, excluding the building.

Tax-Exempt Value

The portion of assessed value exempt from tax (e.g. STAR, veterans, or non-profit exemptions).

Likely Rent Stabilized

Whether the building is likely subject to NYC rent stabilization, which caps how much rent can rise each year.

Why it matters: Great for renters (capped increases, renewal rights); a constraint on an investor's rent upside.

Neighborhood & Health

Community District

The NYC Community District (a local planning/service area, each with a Community Board) the property sits in.

Council District

The NYC City Council district — which council member represents the property.

Census Tract

The U.S. Census tract — a small statistical area used to report neighborhood demographics.

Transportation

Search Radius

How far out from the property this source looked for results (shown in feet or miles).

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