604 Union Street, Brooklyn
Commercial · built 1941 · Block 441, Lot 21.
Building permits
- New Building — Large Residential, filed May 21, 2026, 85 units, 9 stories, early work permitted while the building plans are in review, described as “(please assign to dev hub) proposed new 9 story and cellar mixed use building”
- Alteration, filed Aug 27, 2026, estimated cost $4K, described as “Installation of overhead protection as per plans. All equipment shall comply with chapter #33 of the NYC building code 2022. No change in use, occupancy, or egress under this application.”
- Demolition, filed Jun 3, 2026, estimated cost $10K, described as “Full demolition of a one (1) story with cellar building.”
Property taxes
- Assessment
- $993,600
- 2026–27 tax
- $107,678
- Market value (city estimate)
- $2,208,000
- Taxable value
- $992,610
- Assessed land
- $229,500
- Assessed improvements
- $764,100
Zoning
M1-4/R7A: floor area ratio 1.00 built, 4.00 allowed by base zoning.
Flood zone
Current FEMA flood map: zone X, minimal flood hazard.
Recent sales
- Jul 8, 2026: $11,000,000, 8,550 sq ft ($1,287 per sq ft)
Open-market sales since 2016, from the Department of Finance’s sales files.
Board and land use applications
- Gowanus Neighborhood Plan (City Planning 2018K0382): Zoning map change, Zoning text change, City map change, Urban development action area, Completed, decided Dec 6, 2021. The Gowanus Neighborhood Plan is a shared, long-term vision for a thriving neighborhood. It looks to identify strategies for an equitable, resilient and sustainable Gowanus, with more local jobs and housing. The Plan supports community…