321 West 90th Street

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.

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.

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

Recent transfers at this building, from The Roebling Research Library. Prices are the transfer amounts recorded with the NYC Department of Finance; apartment-level detail is checked against the building’s own file in The Roebling Research Library before publishing.

Market read. Most recent trades (2026 to date) cleared a median $1,075/sf (floor-adjusted) across 1 sale. Floor-adjusted means each sale is restated to a constant mix of floors, so the figure can differ from the plain median of the sales listed above. Median listing discount 0.0% from the last ask.

Sales sourced from NYC Department of Finance recorded transfers (BBL 1-01251-0008). Apartment-level facts (line, condition, asking-price context) curated and cross-verified in The Roebling Research Library. Not all transactions cross-verify with ACRIS records — sponsor and LLC purchases sometimes record at stipulated values rather than market price; square footage on co-ops is not officially recorded, figures shown are approximate.

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, is a key input to what the building may 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.

Confirm the landmark permit route. Covered window and exterior alterations need LPC approval; staff approval may apply and ordinary maintenance may be exempt. Interior work requiring a DOB permit also needs LPC review, alongside board consent.

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 help buyers assess the refinancing; they do not guarantee the transaction timetable.

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