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770 Union Street

500Records
16City systems
28Open violations
74.6Penalty rate
Brooklyn · ZIP 11215 · Neighborhood: Park Slope
Open in the map

500 recorded events, 1971–2026, from 16 city data systems. The city's paper trail here is mostly 179 HPD complaints, 147 311 service requests, 57 HPD housing violations.

BoroughBrooklyn 11215
Built1920
Floors4
Res. units9
ClassC1
Owner (PLUTO)770 UNION ST LTD PARNERSHIP
BBL3009570013
BIN3020188

Full record, year by year   Support this site

GRADE B

A modest record — below the level that usually signals systemic problems. More recorded distress than 78% 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 74.6. In ZIP 11215, 70% of residential buildings hold an A and 4% 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 violations28 total — 9 class C (immediately hazardous), 17 class B, 2 class A. Oldest open since 2004-12-31.

status snapshot refreshed weekly from HPD records

Patterns

13 heat or hot-water complaints in the last three years (winter 2023–24: 3 · winter 2024–25: 4 · winter 2025–26: 4 · winter 2026–27: 2). Repeated winter clusters suggest a chronic heating problem.

3
’23–24
4
’24–25
4
’25–26
2
’26–27

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

What 311 hears from this address

35 service requests in the last three years. Most common: HEAT/HOT WATER (6) · PAINT/PLASTER (5) · Rodent (5) · Illegal Parking (4) · DOOR/WINDOW (4) · ELECTRIC (3).

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 (9)
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)770 UNION STR LTD PARTNERSHIP
Head officerGEORGE 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$3,215,200 $1,446,840
2026$2,885,000 $1,298,250
2027$3,328,000 $1,497,600

The city's market estimate has risen 4% between tax years 2025 and 2027.

Building systems

Heating fuelNATURALGAS

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

Subway7 Av — B Q · 0.3 mi straight-line (about an 8-minute walk) · station accessibility: none
Grand Army Plaza — 2 3 · 0.3 mi straight-line (about an 8-minute walk) · station accessibility: none
BusNearest boarding stop: 7 Av / Union St — B67 B69 · 550 ft
Citi BikeCarroll St & 6 Ave · 500 ft · station location as of 2026-09-23; live availability
School zones (2024–25 map)Elementary: P.S. 321 William Penn. 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

770 Union Street

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

35 311 service requests from this address in the last three years — 6 of them about heat or hot water.

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: $173,374 on 1999-04-05 (lender: Carver Federal Savings Bank), covering 2 lots — the amount covers all of them. Face amount at recording — it may have since been paid down, refinanced or satisfied. View the recorded document.

DateRecordAmountPer res. unit
2026-08-25Agreement $2,525,000 — from 770 UNION STREET LIMITED PARTNERSHIP to ALMA BANK $2,525,000
2016-01-27AL&R $3,400,000 — from 770 UNION STREET LIMITED PARTNERSHIP to THE DIME SAVINGS BANK OF WILLIAMSBURGH $3,400,000
2016-01-27Mortgage $1,890,699 — from 770 UNION STREET LIMITED PARTNERSHIP to THE DIME SAVINGS BANK OF WILLIAMSBURGH $1,890,699
2016-01-27Agreement $3,400,000 — from 770 UNION STREET LIMITED PARTNERSHIP to THE DIME SAVINGS BANK OF WILLIAMSBURGH $3,400,000
2011-02-17Mortgage $455,495 — from 770 UNION STREET LIMITED PARTNERSHIP to CAPITAL ONE, N.A. $455,495
2011-02-17Agreement $1,650,000 — from 770 UNION STREET LIMITED PARTNERSHIP to CAPITAL ONE, N.A. $1,650,000
2011-02-17AL&R $1,650,000 — from 770 UNION STREET LIMITED PARTNERSHIP to CAPITAL ONE, N.A. $1,650,000
2008-05-22Agreement $1,238,000 — from 770 UNION STREET LIMITED PARTNERSHIP to WASHINGTON MUTUAL BANK $1,238,000
2008-05-22Mortgage $494,795 — from 770 UNION STREET LIMITED PARTNERSHIP to WASHINGTON MUTUAL BANK $494,795
2003-09-02Mortgage $286,239 — from 770 UNION STREET LIMITED PARTNERSHIP to THE ROSLYN SAVINGS BANK $286,239
1999-04-05Mortgage $173,374 — from 770 UNION STREET LIMITED PARTNERSHIP to CARVER FEDERAL SAVINGS BANK $173,374
1994-08-31Mortgage $143,468 — from KOTSONIS, PENELOPE to QUEENS COUNTY SAVINGS BANK $143,468
1989-06-23Mortgage $206,000 — from KOTSONIS, PENELOPE to INDEPENDENCE SAVS BANK $206,000
1986-08-01Mortgage $20,000 — from KOTSONIS, PENELOPE; KOTSONIS, GEORGE to SHORR, SHIRLEY; HESTERBERG, CLAIRE $20,000

Ten-year activity

50250
2017
2018
2019
2020
2021
2022
2023
43
2024
2025
2026
EnforcementHousing & tenantsOwnership & moneyHealth & systems
Show as table
YearEnforcementHousing & tenantsOwnership & moneyHealth & systemsTotal
201705005
201807018
20190270128
20200300131
20210130114
20220280432
202306039
20241410143
20250170219
20260163322
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The full timeline

Construction 18Enforcement 18Housing & tenants 391Ownership & money 55Health & systems 18

Every one of the 500 recorded events, 1971–2026, is laid out year by year in the full report (print-ready).

Explore: ZIP 11215 · Landlord rankings · How grades work · The map · The Mice Map