666 5th Avenue, Manhattan
Condominium · built 1958 · Block 1268, Lot 7502.
Building permits
- Alteration, filed Sep 28, 2026, estimated cost $35K, described as “Interior demolition work of existing retail space at 1st floor”
- Alteration, filed Aug 19, 2026, estimated cost $211K, described as “Sprinkler modifications in cellar, 1-2 floors. No change in egress, use, or occupancy.”
- No Work, filed Jul 21, 2026
- No Work, filed Jul 21, 2026
- Alteration, filed Jun 24, 2026, estimated cost $25.4M, described as “General construction work as shown on plans filed herewith. No change in use, egress or occupancy.”
- Alteration, filed Jun 24, 2026, estimated cost $13.0M, described as “General construction work as shown on plans filed herewith. No change in use, egress or occupancy.”
- Alteration, filed Jun 24, 2026, estimated cost $20.2M, described as “General construction work as shown on plans filed herewith. No change in use, egress or occupancy.”
- No Work, filed Jun 18, 2026, described as “Meeting/dining space accessory to office”
- Alteration, filed Jun 9, 2026, estimated cost $3.8M, described as “General construction as shown on plans filed herewith. No change in use, egress, or occupancy.”
- Alteration, filed Jun 2, 2026, estimated cost $5K, described as “Installation of a heavy duty sidewalk shed as per plans during general construction work. No changes in use, egress or occupancy. Sidewalk shed to comply with 2022 NYC building code, chapter 33”
- Alteration, filed May 20, 2026, estimated cost $2.0M, described as “Structural work for reinforcement of existing steel beams to support floor loading and new convenience stairs and framing for slab openings, as shown on plans filed herewith. No change in use, egress or occupancy.”
- Alteration, filed May 19, 2026, estimated cost $250K, described as “Plumbing work including relocation of storm drainage piping, as shown on plans filed herewith. No change in use, egress or occupancy.”
- Alteration, filed May 5, 2026, estimated cost $10K, described as “Installation of temporary store front plywood enclosure as per plans during general construction work. No change in use, egress or occupancy. Enclosure shall comply with chapter 33 of NYC building code of 2022.”
- No Work, filed Mar 26, 2026, described as “Accessory fitness center for office use. Requesting TPA from 04/13/26 thru 07/12/26 (90 days) 5am-9pm.”
- Alteration, filed Mar 19, 2026, estimated cost $4.7M, described as “General construction as shown on plans filed herewith. No change in use, egress, or occupancy.”
- Alteration, filed Dec 31, 2025, estimated cost $1.6M, described as “General construction to install 3 bays of operable facade on the 5th floor, as shown on plans filed herewith. No change in use, egress or occupancy.”
- Alteration, filed Dec 23, 2025, estimated cost $250K, described as “Filing architectural interior demolition for infrastructure ugprades, slab openings for new elevator and meps risers. Temporary construction, means & methods filed separately by contractor. No change to use, egress or occupancy.”
- Alteration, filed Dec 5, 2025, estimated cost $244K, described as “General Construction as shown on plans filed herewith. No change in use, egress or occupancy.”
- No Work, filed Nov 6, 2025
- No Work, filed Nov 6, 2025
- Alteration, filed Oct 31, 2025, estimated cost $75K, described as “General Construction as shown on plans filed herewith. No change in use, egress of occupancy.”
- Alteration, filed Oct 30, 2025, estimated cost $240K, described as “Infill of an existing opening in the structure at the 7th floor. No change in use, egress or occupancy.”
- Alteration, filed Sep 5, 2025, estimated cost $47K, described as “General Construction as shown on plans filed herewith. No change in use, egress of occupancy.”
- Alteration, filed Aug 5, 2025, estimated cost $1.2M, described as “Modification to existing HVAC system as per plans filed herewith. No change in use, egress or occupancy under this application.”
- Alteration, filed Jul 8, 2025, estimated cost $1.6M, described as “General Construction as shown on plans filed herewith. No change in use, egress or occupancy.”
165 more, older permits are in this building’s full list on the map.
Property taxes
- Assessment
- $449,620,651
- 2026–27 tax
- $44,462,245
- Market value (city estimate)
- $999,157,000
- Taxable value
- $409,865,829
- Assessed land
- $85,950,001
- Assessed improvements
- $363,670,650
- Condo units with their own tax lots
- 5
Zoning
C5-2.5 (part of the lot is C5-3): floor area ratio 21.72 built, above the 12.00 base zoning allows, which bonuses, transfers or older rules can permit.
Flood zone
Current FEMA flood map: zone X, minimal flood hazard.
Recent sales
- Jan 8, 2025: $355,000,000, Apt CU3
Open-market sales since 2016, from the Department of Finance’s sales files.
In the news
WatchHouse Opens First US Location at Newly Redeveloped 660 Fifth Avenue in Midtown, Manhattan, New York YIMBY, May 7, 2024.