# 821A Union Street, Brooklyn

Co-op · 4 units · built c. 1920 · Block 954, Lot 61.

On Umarelli: https://umarelli.org/nyc/3009540061/821a-union-street

More construction in Park Slope: https://umarelli.org/nyc/brooklyn/park-slope.md

Every lot on block 954: https://umarelli.org/nyc/brooklyn/954.md

## Building permits

- Alteration, filed Dec 18, 2025, estimated cost $40K, described as “Install new split a.c. System at APT#3 of existing 4-story building with mechanical work as per plans filed here with. No change in use, egress or certificate of occupancy.”
- Alteration, filed Feb 11, 2020, estimated cost $16K, described as “Exterior renovation of existing apartment on the 4TH floor and penthouse. Structural work to create 2 new skylight openings only. No change of use, occupancy or egress”
- Alteration, filed Dec 20, 2019, estimated cost $10K, described as “Herewith filing for replacement and installation of plumbing fixtures, as per plans submitted.”

## Property taxes

- Assessment: $1,102,050
- 2026–27 tax: $12,726
- Market value (city estimate): $2,449,000
- Taxable value: $142,285
- Assessed land: $12,600
- Assessed improvements: $1,089,450

## Tax breaks

- Co-op and condo abatement, with no end date, a $4,973 credit this tax year.

## Zoning

R6A: floor area ratio 2.93 built, 3.00 allowed by base zoning.

## Recent sales

- Jan 28, 2021: $1,200,000
- Aug 19, 2019: $2,167,000
- Jun 2, 2016: $1,150,000

Open-market sales since 2016, from the Department of Finance’s sales files.

## Flood zone

Current FEMA flood map: zone X, minimal flood hazard.

From New York City and Jersey City public records, refreshed within a day of each release. Sources: https://umarelli.org/sources. Methodology and corrections: https://umarelli.org/methodology