# 45 Martense Street, Brooklyn

Co-op · 66 units · built c. 1937 · Block 5086, Lot 66.

On Umarelli: https://umarelli.org/nyc/3050860066/45-martense-street

More construction in Flatbush: https://umarelli.org/nyc/brooklyn/flatbush.md

Every lot on block 5086: https://umarelli.org/nyc/brooklyn/5086.md

## Building permits

- Alteration, filed Mar 13, 2026, estimated cost $60K, described as “Overhead cellar ceiling repair.”
- Alteration, filed Oct 2, 2025, estimated cost $14K, described as “Exterior masonry wall repair.”
- Alteration, filed Jun 28, 2024, estimated cost $8K, described as “Proposed installation of heavy duty sidewalk shed as per plans. Live load 300 lbs per square feet. Sidewalk shed shall comply with chapter #33 of the NYC building code. No change in use, occupancy, or egress under this application.”
- Alteration, filed Jun 13, 2024, estimated cost $40K, described as “Exterior masonry wall repair.”
- Alteration, filed Dec 16, 2023, estimated cost $44K, described as “Exterior masonry wall repair.”
- Alteration, filed Mar 13, 2023, estimated cost $59K, described as “Renovation of apartment #3H at 3rd floor.”

## Property taxes

- Assessment: $2,044,800
- 2026–27 tax: $196,554
- Market value (city estimate): $4,544,000
- Taxable value: $1,875,628
- Assessed land: $261,450
- Assessed improvements: $1,783,350

## Tax breaks

- Co-op and condo abatement, with no end date, a $37,412 credit this tax year.

## Zoning

R7A: floor area ratio 4.54 built, above the 4.00 base zoning allows, which bonuses, transfers or older rules can permit.

## Recent sales

- Apr 21, 2026: $545,000
- Sep 23, 2025: $312,500
- Jun 10, 2024: $495,000
- May 17, 2024: $495,000
- Oct 13, 2022: $495,000
- Jun 29, 2022: $590,000
- Oct 14, 2021: $520,000
- Sep 23, 2021: $254,600
- Jul 2, 2021: $180,000
- Apr 15, 2021: $225,000

The 10 most recent of 26 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