321 West 90th Street
321 West 90th Street, New York, NY 10024
Upper West Side
BBL 1012510008 · BIN 1034074
- Year built
- 1929
- Type
- Cooperative
- Units
- 55
- Floors
- 9
- Landmark
- No
- Financing
- Up to 80 percent, per listing records — a 20 percent minimum down payment
- Flip tax
- $3.00 per share, per listing records — confirm who pays it and the current rate with the managing agent
Own an apartment here? See what it would sell for.
A Private Pricing Opinion — what your apartment at 321 West 90th Street would likely sell for today, what it costs to sell, and what you’d walk away with — reviewed personally against condition, exposures, renovation quality, and the competition actually on the market.
321 West 90th Street is a nine-story 1929 apartment house on a Riverside Drive side street, built at the end of the 1920s apartment boom. Per LPC, it replaced the last two houses of an 1891 row, Nos. 319 and 321, along with a stable on the site. Margon & Holder designed it for the 323 West 90th Street Corporation. It is 75 feet wide, faced in buff brick with limestone and terra-cotta trim, and sits in the original 1989 Riverside–West End Historic District.
Two structural facts matter most to a buyer. The first is the conversion. The co-op came out of a non-eviction plan: tenants who chose not to buy kept their rent-regulated tenancies, and their apartments were sold subject to those tenancies. The plan was first offered in August 1985 by 321 West Company, a New York limited partnership, as sponsor. The owners corporation took title from the building's owner, Polansky Holding Co., in October 1986. The plan gave the sponsor's unsold shares the usual protections: no board approval for sales or sublets, and no flip tax. How many apartments, if any, are still held as unsold shares is not in the public record. That is the first question to put to the managing agent.
The second is the underlying mortgage, the loan the co-op corporation itself carries. In May 2025 ACRIS recorded the co-op refinancing with a new lender, consolidating its existing debt with about $1.17 million of new money into a single $3.5 million loan. Its rate, amortization and maturity are not public. They belong in the first set of financials a buyer requests.
Architecture and unit composition
LPC's 1989 survey describes a façade divided by stringcourses into a two-story base, a five-story midsection and a two-story top. The central entrance has a classically inspired stone surround with a modillioned cornice and a wrought-iron railing above, with five window bays on each side. In the first two stories the windows are paired inside double-height stone surrounds. Stone roundels and scrolled brackets decorate the spandrels at the eighth and ninth stories, and a dentiled terra-cotta cornice caps the building. At designation, the original six-over-six wood windows had already been replaced with one-over-one aluminum sash, and the entrance doors, canopy and lanterns were not original.
The dumbbell plan, with light courts cut into the east and west sides, gives more apartments side exposure than a 75-foot mid-block lot otherwise would. The offering plan allocated 18,845 shares across 54 apartments. The combinations since then (4D/4E in 2003, 4A/4B in 2007, 9D/9E in 2013) have produced a handful of larger apartments at the top of the range. DOB also records a 2010 permit to restore an existing greenhouse at the roof level. Ask the managing agent which apartment it belongs to and whether it is included in that apartment's lease.
Building operations
This is a mid-size, self-service cooperative: an elevator, a live-in superintendent, intercom entry, a laundry room, a bicycle room and storage. No doorman appears in the records reviewed.
Heating plant. DOB signed off in 2016 on two new gas-fired low-pressure steam boilers, a new gas service and the abandonment of the fuel-oil storage tank. The oil-to-gas conversion is done.
Façade. DOB records façade repairs from the first floor to the roof signed off in 2007, further exterior repairs signed off in 2013, and chimney work in 2014. Filings under the city's façade inspection program (Local Law 11) were classified Safe With a Repair and Maintenance Program in Cycle 6 (2007) and Cycle 8 (2019), and Safe in Cycle 7 (2013) and Cycle 9 (July 2023). Because the building is landmarked, façade and window work also needs LPC approval.
Underlying mortgage. ACRIS traces the co-op's borrowing. The sponsor held the first mortgage at conversion. A co-op lender refinanced it in 2005 and again in 2015, when a $2.5 million first mortgage and a separate $500,000 instrument were recorded, and added a $700,000 loan in 2021. In May 2025 the co-op moved its debt to a new lender and consolidated it at $3.5 million. Ask whether any part of the 2025 financing is a credit line, and what the rate and maturity are.
J-51, start to finish. J-51 is a city tax benefit for building improvements. DOF's J-51 records show two benefits on this lot, one begun in 1986 that ran through the 1996 tax year and one begun in 1988 that ran through 1998. Nothing is active. The current roll shows only shareholder-level exemptions and the standard co-op abatement, which passes through to eligible shareholders.
Finances. No audited statements or budget newer than the offering plan's were on file. Ask for the two most recent audited statements, the current budget, the reserve balance and any assessment history.
Policy framework
Flip tax: $3.00 per share, per listing records. Confirm the rate, and whether it is paid by the seller, with the managing agent.
Financing: Up to 80 percent, per listing records.
Subletting: Board consent required under the proprietary lease described in the offering plan; listing records describe sublets as permitted. Get the current sublet policy (term limits, fees, how often) in writing.
Pets: Permitted, per listing records. Confirm the current house rules.
Pied-à-terre, co-purchasing, guarantors, trusts and LLCs: Not documented in the records reviewed. Get these from the managing agent before relying on them.
Recent sales
At 54 apartments, 321 West 90th Street sees a few share transfers a year in ACRIS, and some years only one. As a cooperative it is priced per room, not per square foot. The combined apartments set the top of the range, and the smallest single apartments are the entry point. Floor, exposure (street, light court or rear) and renovation condition account for most of the spread within a line. With this few trades, a two-sale median is noise. Any market statement should be indexed to 2025, the last complete year.
Unit-level transaction history is maintained in The Roebling Research Library and shared with clients during diligence.
The retrade record
Lines that have traded more than once in the public record — the building’s appreciation arc, apartment by apartment.
Recent transfers at this building, sourced from NYC Department of Finance records. Apartment-level detail (line, condition, asking-price context) verified upon consultation request.
| Date | Unit | Price |
|---|---|---|
| Aug 12, 2026 | 3E | $850,000 |
| Sep 26, 2025 | 2F/3F | $1,400,000 |
| Aug 5, 2024 | 5B | $880,500 |
| Jun 21, 2024 | 8D | $752,000 |
| Jan 29, 2024 | 2-D | $730,000 |
| Sep 28, 2022 | 3E | $675,000 |
Sales sourced from NYC Department of Finance recorded transfers (BBL 1-01251-0008) and verified listing data. Apartment-level facts (line, condition, asking-price context) curated and cross-verified by The Roebling Team research desk. Not all transactions cross-verify with ACRIS records — sponsor and LLC purchases sometimes record at stipulated values rather than market price.
Buying here? Co-op closing costs typically run 2 to 3% of the price. See NYC co-op and condo closing costs, line by line.
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What to know if you’re buying
Underwrite the 2025 mortgage. Get the rate, maturity and amortization of the $3.5 million consolidated loan, and ask what the new money paid for. That loan, and not the maintenance figure alone, tells you what the building will cost over the next decade.
Ask about unsold shares. The 1985 plan was non-eviction. Ask whether any apartments are still held by a sponsor or investor, how many are occupied by rent-regulated tenants, and whether the holder is current on maintenance.
Plan on 20 percent down and the per-share flip tax. Financing tops out at 80 percent per listing records. The flip tax is set per share, so its dollar amount depends on the apartment's share allocation. Ask for that number early.
Landmark rules apply to the outside. Windows and anything visible from the street go through LPC as well as the board.
What to know if you’re selling
Lead with the building and the block. A 1929 Margon & Holder façade in the original Riverside–West End Historic District, half a block from Riverside Park, with the heating plant already converted to gas, is a clear story.
Price against the same line. With few recorded trades, a building average means little. Recent sales in the same line, adjusted for floor and condition, are the comparison buyers and appraisers will use.
Bring the financials. Buyers will ask about the 2025 refinancing. Current audited statements and a completed managing-agent questionnaire remove the likeliest delay.
Comparable buildings
If you're considering 321 West 90th Street, also evaluate:
- 320 West 90th Street — Sylvan Bien's 1936 Art Deco cooperative directly across the street, 36 apartments
- 180 Riverside Drive — 1922 Schwartz & Gross cooperative at the Riverside Drive end of the same block
- 186 Riverside Drive — Emery Roth's 1928 cooperative on Riverside Park, full-service
- 190 Riverside Drive — 1910 Ralph S. Townsend building on Riverside at West 91st Street, a condominium conversion
- 639 West End Avenue — The Arbutus, a 1927 neo-Renaissance cooperative on the same block
- 645 West End Avenue — The Halsworth, Gaetano Ajello's 1913 cooperative on the same block
- 320 West 89th Street — 1922 George F. Pelham cooperative one block south, a smaller side-street co-op
- 345 West 88th Street — 1915 Rouse & Goldstone courtyard cooperative near Riverside
More Upper West Side buildings
- 320 West 90th Street — 1936 co-op by Sylvan Bien
- The Royal Summit, 320 West 86th Street — 1915 co-op by Milliken & Moeller
- 321 West 78th Street — 1925 co-op
- 322 West 72nd Street — 1924 co-op by George and Edward Blum
- 323 West 83rd Street — 1897 co-op
- 323 West 86th Street — 1926 co-op by Rosario Candela
The neighborhood
For the full corridor — architecture, transit, and pricing across Upper West Side — read The Roebling Team Guide to Upper West Side.
The full playbook — what goes in the package, how boards read your financials, the interview, and the timeline — plus sample cover, reference, and personal letters you can adapt.
How to read the facts on this page. Items attributed to an offering plan describe the building as it was offered at that filing — unit mix, square footage, the amenity program as planned. They are not a statement about how the building operates today. Tax and compliance figures are sourced separately to current City records and carry their own dates. House rules, staffing and fee policy can change by board resolution without any public filing: treat every policy line here as a starting point for diligence and confirm it with the managing agent. Where this page compares one building or neighborhood to another, that is our analysis of the recorded record — it names the measure, the period and the sample it rests on, and it is an observation about medians rather than a prediction about any particular apartment.
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