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Brooklyn · Block 3279 · Lot 3 · 11237

423 Knickerbocker Avenue

3 floors · 2 apartments · 5,200 sq ft · built 1931 · class S2 · owner of record: 423 Knickerbocker Llc

10open violations
$6,250ECB/OATH penalties owed
0HPD class C (immediately hazardous)
69dto Gas piping inspection (2026 cycle)

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New violations the morning after they're issued, plus deadline reminders. Free for one building.

Compliance deadlines

RequirementDueStatus
Gas piping inspection (2026 cycle) Likely applies
Local Law 152 · During 2026
What this is

Buildings with gas piping (except one- and two-family homes) need a periodic gas piping inspection by a licensed master plumber every four years. Community district 4 is on the 2026 cycle; certification is filed with DOB after the inspection. Buildings with no gas piping file a certification instead. Agency page

Dec 31, 2026
in 69 days		Due this year
Annual parapet observation Check
Local Law 126 · By December 31 each year
What this is

If the building has a parapet facing a street, sidewalk or other public way, a competent person (such as a mason, engineer or architect) must observe it every year and the owner keeps the report for DOB on request. Detached one- and two-family homes are exempt. Agency page

Dec 31, 2026
in 69 days		Keep the report on file (not filed with DOB)
Annual property registration Check
HPD registration · September 1 each year
What this is

Residential buildings with three or more units, and one- and two-family homes the owner doesn't occupy, register with HPD every year ($13 fee). An unregistered building can't start a nonpayment case in Housing Court and faces civil penalties. Agency page

Sep 1, 2027
in 313 days		Required only if the owner doesn't live there

Open violations

ECB / OATH (1) · $6,250 owed
IssuedViolationHearingBalance
Aug 16, 2022Plumbing CLASS - 2
BOILER DETAILS INCORRECT ON PLANS AS PER FGC-106.7. FLUE TERMINATION INCORRECT AND MISSING LOCKING CLIPS ON VENTING EXHAUST AS PER MANUFACTURES INSTRUCTIONS FGC-502.5. MANUAL RESET LOW WATER CUT OFF MISSING AS
#39072738M		Aug 21, 2023
DEFAULT		$6,250
DOB (5)
IssuedViolationStatus
Dec 31, 2009LOW PRESSURE BOILER

#14031		DOB VIOLATION - ACTIVE
Jan 1, 2009LOCAL LAW 62/91 - BOILERS

#15080		DOB VIOLATION - ACTIVE
Jun 1, 1994LOCAL LAW 62/91 - BOILERS

#14285		DOB VIOLATION - ACTIVE
Aug 16, 1993LOCAL LAW 62/91 - BOILERS

#28768		DOB VIOLATION - ACTIVE
Jun 1, 1993LOCAL LAW 62/91 - BOILERS

#14284		DOB VIOLATION - ACTIVE
DOB NOW Safety (4)
IssuedViolationStatus
Dec 31, 2009Boiler LBLVIO
Active
Jan 1, 2009Boiler LL6291
Active
Jun 1, 1994Boiler LL6291
Active
Jun 1, 1993Boiler LL6291
Active
HPD (0)

None open.

Check the agency records

Always confirm on the city's own systems before acting: DOB BIS property profile · DOB NOW · HPD Online · Pay ECB/OATH penalties (CityPay)

City records as of Oct 23, 2026, 3:43 PM ET. BBL 3032790003.

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