351 Park Avenue South

351 Park Avenue South has about 244,000 square feet of floor area in total, including 217,000 square feet of office, 17,000 square feet of retail and 10,000 square feet of industrial and storage space, according to NYC PLUTO 26v2. These are the city's estimates for the whole building, not space that is available.

City records list 1913 as the year built, with a major alteration recorded in 1988. The building is 12 floors tall.

City records list 101 East 25th Street, 100-104 East 26th Street and 343-361 Park Avenue South on the same tax lot (BBL 1008810001) as 351 Park Avenue South. A space listed on Leasemark at any of these addresses shows up on this page.

351 Park Avenue South is in ZIP code 10010, according to the city's tax lot records (NYC PLUTO 26v2) and the Department of Finance's assessment roll. The full mailing address is 351 Park Avenue South, New York, NY 10010, in Flatiron.

The lot is in the C6-4A zoning district. PLUTO lists a built floor area ratio (FAR) of 11.77 and a maximum commercial FAR of 10 for this lot.

The closest subway station to 351 Park Avenue South is 28 St (the 6 train), about 550 feet away in a straight line, roughly 2 minutes on foot. The MTA lists it as partly accessible. Also nearby: 23 St-Baruch College (the 6 train), 3 min walk; 23 St (the R and W trains), 5 min walk. Walking times are straight-line estimates; the street route is longer.

The NYC Department of Finance's 2026/27 assessment roll lists 345 PAS HOLDING LLC as the owner of record of 351 Park Avenue South (BBL 1008810001). Big buildings are usually held through a company set up for that one property, so the name on the roll can differ from the landlord's brand or the managing agent. Deeds and mortgages for the lot are public in ACRIS, the city's property records system.

Leasemark does not have the building's tenant roster, but SEC filings name companies with offices at 351 Park Avenue South. 2 public companies report the address as their principal executive office: LEXEO THERAPEUTICS, INC. (LXEO); and PROTARA THERAPEUTICS, INC. (TARA). 2 investment managers and funds file 13F holdings reports from the address: DEERFIELD MANAGEMENT COMPANY, L.P.; and Deerfield UGP, LLC. Private companies do not file with the SEC, so the full list of tenants is longer, and a company can also report a building it owns.

351 Park Avenue South last sold in September 2019 for $344.5 million, according to the deed recorded with the city. 345 PAS OWNER, LLC sold it to 345 PAS HOLDING LLC. That comes to about $1,411 per square foot of floor area. The deed is ACRIS document 2019091200295001 (BBL 1008810001) in the city's property records. A sale of the company that owns a building is not recorded as a deed, so it would not show there.

351 Park Avenue South's 2024 Local Law 84 benchmarking filing got no ENERGY STAR score (no single use that ENERGY STAR scores covers more than half of the floor area), and Local Law 33 letter grades come from that score, so the filing does not yield an A to D grade. Its site energy use came to 143.7 kBtu per square foot, 6% below the national median of 152.5 for a similar property. Its greenhouse gas emissions were about 3,475 metric tons of CO2e (13.87 kg per square foot).

In the 12 months to October 2026, the Department of Buildings issued first permits for 2 jobs at 351 Park Avenue South. In the last two years, interior work was permitted on 7 floors (floors 1, 2, 4, 5, 8, 9 and 11). The newest build-out, on floor 5, was first permitted in September 2026 (construction, mechanical; filed cost estimate $1.9 million). A sidewalk shed permit here is active until December 30, 2026. These are the Department of Buildings' DOB NOW work permits for tax lot 1008810001. A permit is approval to do the work; it does not say who the work is for or whether it is finished.

The Department of Finance's 2026/27 assessment roll lists exemptions covering the whole taxable value of 351 Park Avenue South, so there is no property tax on the roll to estimate. That is common for government, nonprofit and payment-in-lieu-of-taxes (PILOT) properties. The city's property tax records for BBL 1008810001 show what is actually billed.

For tax year 2026/27, the NYC Department of Finance puts the market value of 351 Park Avenue South at $90 million ($32.9 million of it land) and its assessed value at $40.5 million, the 45% of market value the city assesses for Class 4 property. The city's market value rose 21% from 2022/23 ($74.3 million) to 2026/27.

Owners registered 3 storefronts at 351 Park Avenue South for December 31, 2025, the newest annual filing the city has published, and 1 of them stood vacant that day. These are the owners' filings with the Department of Finance under Local Law 157, so a storefront vacant on December 31, 2025 may have been leased since. Owners and brokers can list a storefront on Leasemark for free.

No space at 351 Park Avenue South is listed on Leasemark right now. Owners and brokers can list space here for free, and tenants can post a requirement to be matched when space opens up.