309 Knickerbocker Avenue, Brooklyn, NY 11237

Lot & building

Basic facts about the tax lot and building from the city’s PLUTO database.

Owner (as listed by the city)

HARTNICK ENTERPRISESINCThe owner name on the city’s tax records. It can lag behind recent sales and is often an LLC.

Building class

S5 – Mixed-use: five- or six-family home with one store or officeThe Department of Finance’s category for what kind of building this is.

Land use

Mixed residential & commercialCity Planning’s broad category of how the lot is used.

Year built

1931Often an estimate for older buildings.

Floors

4

Units

6 residential / 7 totalResidential units are apartments; total includes stores and offices.

Buildings on lot

1

Lot size

2,500 sq ft (25 ft × 100 ft)

Building floor area

7,410 sq ft (incl. 1,853 sq ft commercial)

Zoning

R6, C1-3The zoning district sets what can be built and used here. Residential district; the overlay (C1/C2…) allows local retail on residential blocks.

Built vs. allowed density (FAR)

2.96 built / 2.43 max residentialFloor Area Ratio = building floor area ÷ lot area. If built FAR is below the maximum, zoning may allow more floor area (other rules apply).

Identifiers

BBL 3032200001 (Borough 3, Block 3220, Lot 1) · BIN 3073199BBL identifies the tax lot; BIN identifies each building (from DOB/HPD/footprint records).

Agency lookups: DOB BIS · ZoLa (zoning map) · ACRIS

Source: PLUTO (Dept. of City Planning) — city dataset updated 2026-08-24; data as of 2026-10-31; Building Footprints — city dataset updated 2026-10-25; data as of 2026-10-31

Tax assessment

How the Department of Finance values this lot for property tax.

Market value (tax year 2027, final roll)

$1,690,000The Department of Finance’s estimate of value for tax purposes. It is not an appraisal and is often far from the sale price.

Assessed value

$760,500The portion of market value that taxes are calculated on (capped by law for small homes).

Taxable value (final)

$251,957Assessed value minus any exemptions.

Tax class

Tax class 2B – residential rental, 7–10 units

Source: DOF Property Valuation and Assessment Data — city dataset updated 2026-09-14; data as of 2026-10-31

Sales & deed history 3

Deeds recorded with the City Register (ACRIS). A deed transfers ownership. A $0 or very low price usually means a transfer between related parties, an estate, or a refinance-related transfer, not a market sale. This is not a title search; mortgages, liens and other documents are not shown.

Source: ACRIS Real Property Master — city dataset updated 2026-10-08; data as of 2026-10-31; ACRIS Real Property Legals — city dataset updated 2026-10-08; data as of 2026-10-31; ACRIS Real Property Parties — city dataset updated 2026-10-08; data as of 2026-10-31

DOB job filings 0 open of 4

A “job” is an application to the Department of Buildings to do construction work. A job marked Permitted, not signed off had a work permit issued but the city has no record of final sign-off (inspection/completion). Old jobs left in this state are common and appear in buyer and lender due diligence; the work may or may not have been done.

Source: DOB NOW: Build – Job Application Filings — city dataset updated 2026-10-30; data as of 2026-10-31; DOB Job Application Filings (BIS) — city dataset updated 2026-10-30; data as of 2026-10-31

Work permits 8

Individual permits issued under DOB jobs (one job can have several permits, e.g. plumbing and construction). Permit expiration alone does not mean the job was completed or signed off.

Source: DOB NOW: Build – Approved Permits — city dataset updated 2026-10-30; data as of 2026-10-31; DOB Permit Issuance (BIS) — city dataset updated 2026-10-31; data as of 2026-10-31

DOB violations 2 active of 20

Violations issued by the Department of Buildings for building-code or zoning conditions. Active means DOB has not recorded the violation as resolved or dismissed. Many active DOB violations are old (e.g. elevator or boiler inspection paperwork).

Showing 15 of 20 records. The API and the source dataset have the full list.

Source: DOB Violations — city dataset updated 2026-10-31; data as of 2026-10-31

ECB violations (DOB) 0 active of 18

DOB violations that go to a hearing at OATH (formerly the Environmental Control Board) and can carry fines. Active means the condition has not been certified as corrected and/or the case is not resolved. A balance due is a fine the city says is unpaid.

Showing 15 of 18 records. The API and the source dataset have the full list.

Source: DOB ECB Violations — city dataset updated 2026-10-31; data as of 2026-10-31

OATH tickets (all agencies) 57 unpaid of 226

Summonses heard at the Office of Administrative Trials and Hearings, from agencies like Sanitation, Buildings, Fire and Health, linked to this lot’s block and lot. Default means the respondent did not appear at the hearing, which typically results in the maximum penalty. Tickets may be issued to tenants or businesses at the address, not just the owner. DOB ECB tickets appear here too.

Showing 12 of 226 records. The API and the source dataset have the full list.

Source: OATH Hearings Division Case Status — city dataset updated 2026-10-31; data as of 2026-10-31

HPD registration & contacts

Owners of most rental buildings must register with the Department of Housing Preservation and Development each year and list an owner and managing agent.

HPD building ID

321235

Last registered

2024-08-14

Registration valid until

2025-09-01 ExpiredRegistrations must be renewed every year.

Source: HPD Multiple Dwelling Registrations — city dataset updated 2026-10-28; data as of 2026-10-31; HPD Registration Contacts — city dataset updated 2026-10-28; data as of 2026-10-31

HPD housing-code violations 63 open of 109

Violations HPD inspectors issued for conditions in residential buildings (heat, leaks, mold, pests, lead paint, etc.). Class letters show how serious: Class A – non-hazardous (HPD gives 90 days to correct); Class B – hazardous (30 days to correct); Class C – immediately hazardous (24 hours to correct for most conditions); Class I – information / order (e.g. orders to register, lead or other administrative orders). Open means HPD has not recorded the condition as corrected.

Showing 20 of 109 records — open violations are listed first; the API lists every one. The API and the source dataset have the full list.

Source: HPD Housing Maintenance Code Violations — city dataset updated 2026-10-31; data as of 2026-10-31

HPD complaints 14

Complaints tenants or others made to HPD (usually via 311) about housing conditions, from 2019 onward. A complaint is not a violation; HPD may inspect and issue one.

Showing 10 of 14 records. The API and the source dataset have the full list.

Source: HPD Housing Maintenance Code Complaints and Problems — city dataset updated 2026-10-31; data as of 2026-10-31

311 requests (last 12 months) 6

Recent 311 service requests the city geocoded to this lot: noise, illegal parking, heat, sanitation and more. Anyone can file them, so they describe activity at or near the address, not necessarily the building itself.

Source: 311 Service Requests from 2020 to Present — city dataset updated 2026-10-31; data as of 2026-10-31

Nearby properties

On Knickerbocker Ave

• 308 Knickerbocker Avenue (five open items)
• 307 Knickerbocker Avenue (four open items)
• 306 Knickerbocker Avenue (40 open items)
• 312 Knickerbocker Avenue (eight open items)
• 305 Knickerbocker Avenue (10 open items)
• 313 Knickerbocker Avenue (53 open items)
• 302 Knickerbocker Avenue (11 open items)
• 301 Knickerbocker Avenue (seven open items)
• 317 Knickerbocker Avenue (29 open items)
• 300 Knickerbocker Avenue (24 open items)

Same tax block (3220)

• 307 Knickerbocker Avenue (four open items)
• 305 Knickerbocker Avenue (10 open items)
• 301 Knickerbocker Avenue (seven open items)
• 299 Knickerbocker Avenue (46 open items)
• 291 Knickerbocker Avenue (38 open items)
• 278 Suydam Street (two open items)
• 280 Suydam Street (three open items)
• 282 Suydam Street (one open item)
• 284 Suydam Street (one open item)
• 286 Suydam Street (two open items)

All properties on Knickerbocker Ave, Brooklyn · All of Brooklyn 11237 (Bushwick (West))