# 343 West 21st Street, Manhattan

Apartment building · 15 units · built c. 1920 · Block 745, Lot 13.

On Umarelli: https://umarelli.org/nyc/1007450013/343-west-21-street

More construction in Chelsea: https://umarelli.org/nyc/manhattan/chelsea.md

Every lot on block 745: https://umarelli.org/nyc/manhattan/745.md

## Building permits

- Alteration, filed Sep 24, 2026, estimated cost $26K, described as “Replacement of the chimney at the roof level only including minor masonry work, liner replacement, with associated mechanical and structural work. The existing membrane on the roof floor is to remain. No change to the use, egress, or…”

## Property taxes

- Assessment: $728,550
- 2026–27 tax: $85,742
- Market value (city estimate): $1,619,000
- Taxable value: $689,300
- Assessed land: $112,500
- Assessed improvements: $616,050

## Zoning

R7B: floor area ratio 2.84 built, 3.00 allowed by base zoning.

## 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