347 Warren Street, Brooklyn
Three-family · built c. 1899 · Block 391, Lot 54.
Building permits
- Alteration, filed Aug 31, 2026, estimated cost $1K, described as “Proposed horizontal and vertical enlargement of existing three-story & basement, three-family building, with renovation throughout as per plans. No change in use, egress, or occupancy.”
- Major Renovation — Conversion, filed Mar 10, 2025, 1 unit added, 4 stories, described as “Application is filed for a conversion from 3 family to 4 family with a vertical and horizontal extension. Obtain new certificate of occupancy.”
Property taxes
- Assessment
- $211,260
- 2026–27 tax
- $8,190
- Market value (city estimate)
- $3,521,000
- Taxable value
- $41,275
- Assessed land
- $29,700
- Assessed improvements
- $181,560
Zoning
R6B: floor area ratio 1.21 built, 2.00 allowed by base zoning.
Flood zone
Current FEMA flood map: zone X, minimal flood hazard.
Recent sales
- Dec 30, 2024: $2,500,026
- Dec 5, 2023: $1,965,000
Open-market sales since 2016, from the Department of Finance’s sales files.