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21 Sterling Place

123Records
12City systems
5Open violations
10Penalty rate
Brooklyn · ZIP 11217 · Neighborhood: Park Slope
Open in the map

123 recorded events, 1970–2026, from 12 city data systems. The city's paper trail here is mostly 36 311 service requests, 21 ACRIS deeds & mortgages, 21 HPD complaints.

BoroughBrooklyn 11217
Built1920
Floors4
Res. units6
ClassC2
Owner (PLUTO)21 STERLING PLACE LLC
BBL3009410071
BIN3019031

Full record, year by year   Support this site

GRADE A

The city's published records show little recorded distress here in the last three years. Less recorded distress than 62% of 6-24-unit residential buildings citywide. The citywide median for 6-24-unit residential buildings is 16.3 penalty points per 10 units; this building carries 10. In ZIP 11217, 60% of residential buildings hold an A and 6% grade D or F. How grades work

this building
A
B
C

Among 46,798 6-24-unit residential buildings citywide · left is less recorded distress, right is more

Open with the city right now

Open HPD violations5 total — 0 class C (immediately hazardous), 0 class B, 5 class A. Oldest open since 2026-06-06.

status snapshot refreshed weekly from HPD records

Patterns

No heat or hot-water complaints in the last three years.

No bedbug-infested units reported in the last three years of filings.

What 311 hears from this address

3 service requests in the last three years. Most common: Dead Animal (1) · Noise (1) · Curb Condition (1).

Filed construction activity

No permitted work with a declared cost filed in the last decade. Permit costs cover filed construction work only — they do not capture routine maintenance or repairs done without a permit.

Rent-stabilization signals

YesBuilt before 1974 (1920)
YesSix or more residential units (6)
No421-a / J-51 tax benefit on the current tax roll

2 of 3 signals present. This is the classic profile of a rent-stabilized building (pre-1974, 6+ units) — many units in such buildings remain stabilized. The definitive answer for any unit: request its rent history from NYS Homes & Community Renewal (free, at hcr.ny.gov).

Registered with HPD — the names behind the building

Registered owner(s)21 STERLING PL LLC
Head officerNICHOLAS G KOTSONIS
Managing agentKOTSONIS ORGANIZATION LLC.
Last registered2025-10-11

as filed by the owner in the building's HPD registration

What the city thinks it's worth

Tax yearCity market valueAssessed value
2025$2,749,200 $1,237,140
2026$3,299,000 $1,484,550
2027$3,139,000 $1,412,550

The city's market estimate has risen 14% between tax years 2025 and 2027.

Flood exposure

Not in the FEMA 1%-annual-chance floodplain (2015 preliminary maps).

Not in a hurricane evacuation zone.

Not in the city's stormwater (cloudburst) flood maps under any modeled scenario.

No street-flooding or sewer-backup complaints on record at this address.

Sources: FEMA flood maps (coastal), NYC DEP Stormwater Flood Maps (cloudburst), NYC hurricane evacuation zones, and 311 records for this address.

Getting around

SubwayBergen St — 2 3 · 950 ft straight-line (about a 5-minute walk) · station accessibility: none
7 Av — B Q · 0.3 mi straight-line (about a 7-minute walk) · station accessibility: none
BusNearest boarding stop: 5 Av / Saint Johns Pl — B63 · 300 ft
Citi BikeSterling Pl & 5 Ave · 200 ft · station location as of 2026-09-23; live availability
School zones (2024–25 map)Elementary: P.S. 282 Park Slope. Confirm with the DOE's school search.

Distances are straight-line, not walking routes. Transit locations from the MTA and Citi Bike, bike facilities from NYC DOT, school zones from the DOE's 2024–25 maps.

Report a problem to 311

21 Sterling Place

Heat or hot waterHeat or hot water
Apartment maintenanceApartment maintenance
Bed bugsBed bugs
Residential pestsResidential pests
Rats or miceRats or mice
Anything elseAnything else

3 311 service requests from this address in the last three years.

311 will ask for the address, the apartment if the problem is inside, and what's wrong. Contact details are optional for most complaints; food-poisoning reports can be anonymous. Complaints appear in the city's public 311 data, usually within a day or two, and then in the Live from 311 box on this page.

The landlord's report card

Managed by KOTSONIS ORGANIZATION LLC. — 27 buildings, 239 units. Grades across the portfolio: A20 · B6 · C1. See the whole portfolio

BuildingBoroughUnitsGrade
94 Prospect Park West BK30 A
594 6 Street BK16 B
101 Prospect Park West BK10 A
767 Union Street BK10 A
549 Bergen Street BK10 B
770 Union Street BK9 B
886 Union Street BK9 B
392 Prospect Avenue BK8 A
693 Union Street BK8 A
873 Union Street BK8 A
845 President Street BK8 A
195 5 Avenue BK8 A
896 Union Street BK8 B
768 Union Street BK8 A
298 1 Street BK8 A
898 Union Street BK8 B
664 6 Avenue BK8 A
695 Union Street BK8 A
800 President Street BK8 A
134 29 Street BK8 A
832 Union Street BK7 A
74 Douglass Street BK7 A
248 5 Avenue BK7 A
21 Sterling Place BK6 A
633 10 Street BK6 A
287 19 Street BK5 A
287 6 Avenue BK3 C

Sales, deeds & mortgages

Most recent mortgage recorded against this lot: $227,092 on 2022-11-15 (lender: Alma Bank). Face amount at recording — it may have since been paid down, refinanced or satisfied. View the recorded document.

DateRecordAmountPer res. unit
2022-11-15Agreement $2,050,000 — from 21 STERLING PLACE LLC to ALMA BANK $2,050,000
2022-11-15Mortgage $227,093 — from 21 STERLING PLACE LLC to ALMA BANK $227,093
2018-06-22Agreement $6,900,000 — from 21 STERLING PLACE LLC; 695 UNION STREET, LLC; 248 5TH AVENUE REALTY CORP. to DIME COMMUNITY BANK $6,900,000
2018-04-27Agreement $2,000,000 — from 21 STERLING PLACE LLC to DIME COMMUNITY BANK $2,000,000
2018-04-27Mortgage $625,491 — from 21 STERLING PLACE LLC to DIME COMMUNITY BANK $625,491
2018-04-27Mortgage $1,374,509 — from 21 STERLING PLACE LLC to DIME COMMUNITY BANK $1,374,509
2018-04-27AL&R $2,000,000 — from 21 STERLING PLACE LLC to DIME COMMUNITY BANK $2,000,000
2013-08-29AL&R $6,900,000 — from 21 STERLING PLACE LLC; 695 UNION STREET, LLC; 248 5TH AVENUE REALTY CORP. to INVESTORS BANK $6,900,000
2013-08-29Agreement $6,900,000 — from 248 5TH AVENUE REALTY CORP.; 695 UNION STREET, LLC; 21 STERLING PLACE LLC to INVESTORS BANK $6,900,000
2013-08-29Mortgage $3,317,826 — from 21 STERLING PLACE LLC; 248 5TH AVENUE REALTY CORP.; 695 UNION STREET, LLC to INVESTORS BANK $3,317,826
2007-09-24Mortgage $655,000 — from 21 STERLING PLACE LLC to WASHINGTON MUTUAL BANK $655,000
2007-09-24Deed $1,100,000 — from ALFEROFF, REYNALDO; ALFEROFF, YOLANDA to 21 STERLING PLACE LLC $1,100,000

Ten-year activity

20100
2017
14
2018
2019
2020
2021
2022
2023
2024
2025
2026
Housing & tenantsOwnership & moneyHealth & systems
Show as table
YearHousing & tenantsOwnership & moneyHealth & systemsTotal
20172002
201847314
20191012
20203014
20216017
20223418
20232013
20243014
20253014
20266017
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The full timeline

Construction 9Enforcement 6Housing & tenants 76Ownership & money 21Health & systems 11

Every one of the 123 recorded events, 1970–2026, is laid out year by year in the full report (print-ready).

Explore: ZIP 11217 · Landlord rankings · How grades work · The map · The Mice Map