83 recorded events, 1966–2026, from 12 city data systems. The city's paper trail here is mostly 19 311 service requests, 12 ACRIS deeds & mortgages, 11 DOB permits.
Full record, year by year Support this site
The city's published records show little recorded distress here in the last three years. Less recorded distress than 55% 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 13. In ZIP 11215, 70% of residential buildings hold an A and 4% grade D or F. How grades work
Among 46,798 6-24-unit residential buildings citywide · left is less recorded distress, right is more
No current HPD flags in the latest weekly snapshot: no open violations, no pending litigation, no active vacate orders, and not in the Alternative Enforcement Program.
No heat or hot-water complaints in the last three years.
No bedbug-infested units reported in the last three years of filings.
9 service requests in the last three years. Most common: Dirty Condition (2) · Noise (2) · Residential Disposal Complaint (1) · Emergency Response Team (ERT) (1) · For Hire Vehicle Complaint (1) · GENERAL (1).
$76,250 in permitted construction work filed since 2016 (3 filings with a declared cost) — a rough measure of how actively the owner maintains the building. Permit costs cover filed construction work only — they do not capture routine maintenance or repairs done without a permit.
| Yes | Built before 1974 (1931) |
| Yes | Six or more residential units (8) |
| No | 421-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 owner(s) | 664 6TH AVENUE, LLC. |
| Head officer | NICHOLAS G KOTSONIS |
| Managing agent | KOTSONIS ORGANIZATION LLC. |
| Last registered | 2025-10-11 |
as filed by the owner in the building's HPD registration
| Tax year | City market value | Assessed value |
|---|---|---|
| 2025 | $1,592,000 | $716,400 |
| 2026 | $1,431,000 | $643,950 |
| 2027 | $1,717,000 | $772,650 |
The city's market estimate has risen 8% between tax years 2025 and 2027.
| Heating fuel | NATURALGAS |
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.
| Subway | Prospect Av — R · 0.3 mi straight-line (about an 8-minute walk) · station accessibility: none |
| Bus | Nearest boarding stop: 5 Av / 18 St — B63 · 700 ft |
| Citi Bike | 6 Ave & 21 St · 300 ft · station location as of 2026-09-23; live availability |
| School zones (2024–25 map) | Elementary: Magnet School of Math, Science and Design Technology. 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.
664 6 Avenue
| Heat or hot water | Heat or hot water |
| Apartment maintenance | Apartment maintenance |
| Bed bugs | Bed bugs |
| Residential pests | Residential pests |
| Rats or mice | Rats or mice |
| Anything else | Anything else |
9 311 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.
Managed by KOTSONIS ORGANIZATION LLC. — 27 buildings, 239 units. Grades across the portfolio: A20 · B6 · C1. See the whole portfolio
| Building | Borough | Units | Grade |
|---|---|---|---|
| 94 Prospect Park West | BK | 30 | A |
| 594 6 Street | BK | 16 | B |
| 101 Prospect Park West | BK | 10 | A |
| 767 Union Street | BK | 10 | A |
| 549 Bergen Street | BK | 10 | B |
| 770 Union Street | BK | 9 | B |
| 886 Union Street | BK | 9 | B |
| 392 Prospect Avenue | BK | 8 | A |
| 693 Union Street | BK | 8 | A |
| 873 Union Street | BK | 8 | A |
| 845 President Street | BK | 8 | A |
| 195 5 Avenue | BK | 8 | A |
| 896 Union Street | BK | 8 | B |
| 768 Union Street | BK | 8 | A |
| 298 1 Street | BK | 8 | A |
| 898 Union Street | BK | 8 | B |
| 664 6 Avenue | BK | 8 | A |
| 695 Union Street | BK | 8 | A |
| 800 President Street | BK | 8 | A |
| 134 29 Street | BK | 8 | A |
| 832 Union Street | BK | 7 | A |
| 74 Douglass Street | BK | 7 | A |
| 248 5 Avenue | BK | 7 | A |
| 21 Sterling Place | BK | 6 | A |
| 633 10 Street | BK | 6 | A |
| 287 19 Street | BK | 5 | A |
| 287 6 Avenue | BK | 3 | C |
Most recent mortgage recorded against this lot: $32,763 on 2026-07-16 (recorded via MERS, the industry registry; the lender is not named on the record). Face amount at recording — it may have since been paid down, refinanced or satisfied. View the recorded document.
| Date | Record | Amount | Per res. unit |
|---|---|---|---|
| 2026-07-16 | Agreement $1,585,250 — from 664 6TH AVENUE LLC to MORTGAGE ELECTRONIC REGISTRATION SYSTEMS | $1,585,250 | |
| 2026-07-16 | Mortgage $32,763 — from 664 6TH AVENUE LLC to MORTGAGE ELECTRONIC REGISTRATION SYSTEMS | $32,763 | |
| 2018-03-09 | Deed $2,700,000 — from 664 REALTY HOLDINGS LLC to 664 6TH AVENUE LLC | $2,700,000 | |
| 2018-03-09 | AL&R $1,700,000 — from 664 6TH AVENUE LLC to GOLD COAST BANK | $1,700,000 | |
| 2018-03-09 | Mortgage $1,700,000 — from 664 6TH AVENUE LLC to GOLD COAST BANK | $1,700,000 | |
| 2018-02-09 | Sold for $2,700,000 | $2,700,000 | $337,500 |
| Year | Construction | Enforcement | Housing & tenants | Ownership & money | Health & systems | Total |
|---|---|---|---|---|---|---|
| 2017 | 2 | 0 | 0 | 0 | 1 | 3 |
| 2018 | 5 | 0 | 1 | 4 | 0 | 10 |
| 2019 | 0 | 1 | 3 | 0 | 1 | 5 |
| 2020 | 0 | 0 | 0 | 0 | 1 | 1 |
| 2021 | 0 | 0 | 6 | 0 | 1 | 7 |
| 2022 | 0 | 0 | 3 | 0 | 1 | 4 |
| 2023 | 0 | 1 | 2 | 0 | 1 | 4 |
| 2024 | 0 | 0 | 1 | 0 | 2 | 3 |
| 2025 | 0 | 1 | 5 | 0 | 1 | 7 |
| 2026 | 5 | 0 | 12 | 4 | 1 | 22 |
Every one of the 83 recorded events, 1966–2026, 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