670 Williams Avenue, Brooklyn
Single family · built 2002 · Block 3867, Lot 147.
Building permits
- Alteration, filed Apr 28, 2026, estimated cost $124K, described as “Rear extension of one family with 2 story house.”
- Alteration, filed Jun 17, 2025, estimated cost $46K, described as “Installation of stairs to cellar at front and rear of house.”
Property taxes
- Assessment
- $42,180
- 2026–27 tax
- $5,452
- Market value (city estimate)
- $703,000
- Taxable value
- $27,432
- Assessed land
- $17,640
- Assessed improvements
- $24,540
Tax breaks
- UDAAP exemption, through Jun 30, 2027, about $353 a year below the full tax.
Zoning
R6: floor area ratio 0.74 built, 2.43 allowed by base zoning.
Flood zone
Current FEMA flood map: zone X, minimal flood hazard.