345 Park Avenue

345 Park Avenue has about 1.7 million square feet of floor area in total, including 1.5 million square feet of office, 79,000 square feet of retail and 84,000 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 1969 as the year built. The building is 44 floors tall.

City records list 101-133 East 51st Street, 100-130 East 52nd Street, 576-594 Lexington Avenue and 341-353 Park Avenue on the same tax lot (BBL 1013060001) as 345 Park Avenue. A space listed on Leasemark at any of these addresses shows up on this page.

City records give two ZIP codes for this tax lot: 10022 in NYC PLUTO 26v2 and 10154 on the Department of Finance's assessment roll. Some large New York buildings have a ZIP code of their own beside the area's, so check with the building's management which one it uses before you rely on either.

The lot is in the C5-2.5 zoning district. PLUTO lists a built floor area ratio (FAR) of 21.05 and a maximum commercial FAR of 12 for this lot.

The closest subway station to 345 Park Avenue is 51 St (the 6, E and F trains, connected to Lexington Av/53 St), about 250 feet away in a straight line, roughly 1 minute on foot. The MTA lists it as an accessible station. Also nearby: 5 Av/53 St (the E and F trains), 4 min walk; 59 St (the 4, 5, 6, N, R and W trains, connected to Lexington Av/59 St), 8 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 PARK AVENUE, L.P. as the owner of record of 345 Park Avenue (BBL 1013060001). 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 345 Park Avenue. 10 public companies report the address as their principal executive office: BLACKSTONE INC. (BX); BLACKSTONE REAL ESTATE INCOME TRUST, INC. (BSTT); BLACKSTONE SECURED LENDING FUND (BXSL); APARTMENT INCOME REIT, L.P.; BLACKSTONE INFRASTRUCTURE STRATEGIES L.P.; and 5 more. 3 investment managers and funds file 13F holdings reports from the address: Blackstone Alternative Asset Management L.P., WAFRA INC. and BLACKSTONE ALTERNATIVE CREDIT ADVISORS LP. 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.

345 Park Avenue reported an ENERGY STAR score of 47 for calendar year 2024 in its Local Law 84 benchmarking filing. Under Local Law 33, as amended by Local Law 95 of 2019, a score of 85 or higher earns an A, 70 to 84 a B, 55 to 69 a C and under 55 a D, so 47 earns a D. The Department of Buildings assigns the grade a building posts, so the posted label can differ if a filing was corrected. Its site energy use came to 123 kBtu per square foot, about the same as the national median of 120 for a similar property. Its greenhouse gas emissions were about 19,363 metric tons of CO2e (10.86 kg per square foot).

In the 12 months to October 2026, the Department of Buildings issued first permits for 22 jobs at 345 Park Avenue. In the last two years, interior work was permitted on 23 floors (floors 1, 2, 4, 7, 8, 13, 17, 22, 23, 28, 30 to 40, 43 and 44, the cellar and the sub-cellar). The newest build-out, on floors 22 and 23 and the cellar, was first permitted in September 2026 (construction, mechanical, plumbing, sprinklers, standpipe, structural; filed cost estimate $20 million). A sidewalk shed permit here is active until February 3, 2027. These are the Department of Buildings' DOB NOW work permits for tax lot 1013060001. 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 a taxable value of $458.4 million for 345 Park Avenue. At the Class 4 rate of 10.848% (tax year 2025/26, the latest rate the Department of Finance lists), that is about $49.7 million a year, roughly $29.04 per square foot of floor area, before abatements such as ICAP. The city's property tax records for BBL 1013060001 show the actual bill.

For tax year 2026/27, the NYC Department of Finance puts the market value of 345 Park Avenue at $1.14 billion ($102 million of it land) and its assessed value at $512.2 million, the 45% of market value the city assesses for Class 4 property. The city's market value rose 28% from 2022/23 ($889.2 million) to 2026/27.

Owners registered 3 storefronts at 345 Park Avenue for December 31, 2025, the newest annual filing the city has published, and 1 of them stood vacant that day. A year earlier, none of 2 did. 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 345 Park Avenue is listed on Leasemark right now. Nearby on Leasemark: office space for lease at 783 Madison 4th Floor in the Upper East Side (994 SF, $66.40/SF/yr). Owners and brokers can list space here for free, and tenants can post a requirement to be matched when space opens up.