# 5817 21st Avenue, Brooklyn

Two-family · built c. 1925 · Block 5508, Lot 3.

On Umarelli: https://umarelli.org/nyc/3055080003/5817-21-avenue

More construction in Borough Park: https://umarelli.org/nyc/brooklyn/borough-park.md

Every lot on block 5508: https://umarelli.org/nyc/brooklyn/5508.md

## Building permits

- Alteration, filed Nov 5, 2026, estimated cost $175K, described as “Herewith filing an application for the removal of an existing third floor, filing for a rear extension at floors cel-002 and new bulkhead. Filing for an interior renovation at all floors. Filing to address swo & violation 39204224R.”
- Alteration, filed Apr 29, 2026, estimated cost $5K, described as “Temporary construction fence”
- Alteration, filed Apr 29, 2026, estimated cost $10K, described as “Herewith filing for a renovation ofthe front facade with cement andbricks.no change in use, occupancyor egress.”

## Property taxes

- Assessment: $96,960
- 2026–27 tax: $8,088
- Market value (city estimate): $1,616,000
- Taxable value: $40,759
- Assessed land: $18,600
- Assessed improvements: $78,360

## Zoning

R5: floor area ratio 1.00 built, 1.50 allowed by base zoning.

## Recent sales

- Feb 27, 2017: $998,500

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