# 423 15th Street, Brooklyn

Co-op · 16 units · built c. 1909 · Block 1103, Lot 69.

On Umarelli: https://umarelli.org/nyc/3011030069/423-15-street

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

Every lot on block 1103: https://umarelli.org/nyc/brooklyn/1103.md

## Building permits

No building permits on file for this lot.

## Property taxes

- Assessment: $990,000
- 2026–27 tax: $95,787
- Market value (city estimate): $2,200,000
- Taxable value: $905,795
- Assessed land: $62,550
- Assessed improvements: $927,450

## Tax breaks

- Co-op and condo abatement, with no end date, a $17,247 credit this tax year.

## Zoning

R6B: floor area ratio 2.81 built, above the 2.00 base zoning allows, which bonuses, transfers or older rules can permit.

## Recent sales

- Jul 9, 2026: $900,000
- Apr 28, 2026: $613,000
- Jan 29, 2026: $780,000
- May 8, 2025: $925,000
- Dec 19, 2024: $825,000
- Jul 25, 2024: $765,000
- Jul 20, 2023: $740,000
- Jul 21, 2022: $615,000
- Apr 29, 2021: $895,000
- Jan 20, 2021: $545,000

The 10 most recent of 16 open-market sales since 2016, from the Department of Finance’s sales files.

## Flood zone

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

## Landmarks

Part of Park Slope Historic District Extension (Historic District). 2 Landmarks Preservation Commission permits are on file.

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