610 West End Avenue (The Evanston)

The building occupies a corner lot roughly 101 feet on the avenue by 163 feet on the street, and both street elevations use the same articulation: a one-story banded base over a high basement, a ten-story midsection, and a one-story top. On the avenue, three tripartite window bays sit at the center, flanked by single windows, with paired windows at each end. On West 90th Street the courtyard splits the elevation into two wings — five paired openings per story on the western wing, four on the eastern including three tripartite bays, and inside the courtyard a projecting bowed bay where the eastern and southern walls meet. Original window types included nine-over-one wood sash and multipane casements; by 1989 roughly half had been replaced with one-over-one aluminum, and brackets at the second story marked balconies since removed.

Because the building is a corner with a courtyard rather than a solid block, a high proportion of apartments have two or three exposures, and the duplex plan gives the larger homes an internal stair and a genuine separation between entertaining and sleeping floors. Combinations recorded with the Department of Buildings in 2000, 2006 and 2010 likely account for at least part of the difference between the market's unit count and the city's; buy the specific apartment, not the building average.

The lot sits inside the Riverside–West End Historic District, designated December 19, 1989, and appears in the designation report under its own entry keyed to Block 1237, Lot 61. Exterior alterations generally require an LPC permit, and DOB-permitted work needs LPC clearance where applicable; ordinary maintenance may be exempt. A Certificate of Appropriateness is one permit route; visibility alone does not require full-Commission review, because eligible exterior changes may receive staff approval. A Certificate of No Effect is issued at staff level where protected features are not affected, and a Permit for Minor Work covers in-kind repair and similar items.

The building's permit history, which runs to roughly 190 filings on this lot, shows how that plays out in practice. Two Certificates of Appropriateness appear: one in August 1997 for a rooftop addition, and one in July 2009 for restorative work — the façade restoration campaign. Everything else has been staff-level or administrative: dozens of Certificates of No Effect for interior alterations, a long run of Authorizations to Proceed for air conditioning louvers between 2003 and 2017, Permits for Minor Work for window openings on primary and secondary façades, a Certificate of No Effect in May 2017 for a rooftop addition consisting of unenclosed decks, and a 2026 amendment filed against an HVAC master plan for the building.

That last point is worth flagging for buyers planning a renovation. Recent Landmarks filings here reference through-wall HVAC handled under a master plan, which is the mechanism that allows qualifying units to be permitted at staff level rather than individually before the Commission. Ask the managing agent for the building's master plan and its alteration agreement before you design mechanical systems.

The building runs as a full-service prewar cooperative: full-time doorman, live-in resident manager, passenger and service elevators, central laundry, bike storage, resident storage, and a landscaped common roof terrace.

The roof terrace is recent and its origin is documented. A Certificate of No Effect for unenclosed rooftop decks was issued in May 2017; a Department of Buildings alteration application filed in January 2017 covered partial roof repair and the conversion of part of an existing terrace to a recreation area for residents; a 2018 filing installed accessory rooftop space under the Department's 2018 bulletin on that subject; and a pergola was permitted in June 2019.

The rest of the capital record is a run of systems filings. Department of Buildings filings show a lobby renovation with new marble flooring in 2003; a terra-cotta and brick façade repair with restoration of wood window frames in 2006; a plaza restoration in 2009; exterior repairs in 2010; two lobby lifts installed for accessibility in 2011; boiler and oil burner replacement in 2011 with a change of fuel grade from No. 6 to No. 4 oil and a new stainless steel chimney liner; house water pump replacement with a new backflow preventer and domestic water booster pump, plus a water filtration system, in 2011; a new gas service connected to the burner in 2012; and further façade repairs in 2017. Completion and current condition need confirming with the managing agent and recent engineering reports.

The façade cycle record is the item to read closely, because it is not a clean one. Local Law 11 filings run: Unsafe on the Cycle 6 initial filing in February 2007, amended to Safe in March 2010; Safe in Cycle 7 (2012); Unsafe on the Cycle 8 initial filing in January 2018, amended to Safe in December 2019; Unsafe on the Cycle 9 initial filing in November 2022, with subsequent filings in September 2023, December 2024 and August 2025 still reporting Unsafe conditions, and an amended filing on September 23, 2025 reporting Safe; and Safe on the Cycle 10 initial filing of July 30, 2026. In short: an elaborately ornamented terra-cotta and brick façade that has required substantial remediation in three of the last four cycles, most recently over a roughly three-year Cycle 9 program that closed in September 2025. The building has cleared each one. The question for a buyer is what the current cycle costs and how the last one was paid for.

Ownership form: Cooperative. Purchasers buy shares in 610 West End Corp. together with a proprietary lease, and the purchase is subject to board approval — a full board package and an interview, not a condominium right of first refusal. Budget 60 to 90 days from contract to closing, and assemble the package before you offer rather than after.

Financing ceiling: Not published. The maximum permitted financing at this building is a board policy and must be obtained from the managing agent; the ceiling — not the purchase price — can determine whether a buyer can transact here at all.

Post-closing liquidity: Not published. Assume the board applies a liquidity requirement after closing in addition to the down payment, and obtain the current standard before offering.

Subletting: Not published. Obtain the current policy, seasoning period, maximum term and fee schedule from the managing agent.

Pied-à-terre, co-purchase, guarantors, gifting, trusts and LLC ownership: Not established in the materials reviewed for this profile; obtain current operative policies and their governing authority, and they should be established in writing before an offer is made rather than discovered during package review.

Flip tax: Not published. Confirm whether one exists, at what rate, and on what basis — gross price, net profit, or per share — because the three produce very different seller proceeds.

Real estate taxes and abatement: The cooperative receives the standard co-op/condo property tax abatement, which reduces the tax component of maintenance for eligible resident shareholders. There is no J-51, 421-a or 485-x on this lot. Ask for the current maintenance figure and the portion attributable to real estate taxes.

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 $1,087/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 3.8% from the last ask — a recurring negotiation gap worth pricing into any offer or listing strategy.

Sales sourced from NYC Department of Finance recorded transfers (BBL 1-01237-0061). 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.

You are buying shares, not real property. The transaction is a share transfer with a proprietary lease, closed on board approval after a full package and an interview. Run the Co-op Board Qualification Calculator before you offer, not after.

Get the financing ceiling in writing first. It is not published anywhere, and it is the single fact most likely to end a deal at this building. Ask for it, and ask for the post-closing liquidity standard in the same conversation.

Ask for the audited financials, the underlying mortgage terms and the reserve position. Review the underlying mortgage and maturity alongside operating expenses, reserves and capital plans before ranking the maintenance drivers. The materials reviewed do not establish the current mortgage balance, terms or reserves. We could not locate audited financials for this building in either document library, so this is a request your attorney should make early.

Read the façade history, not just the current status. Three of the last four Local Law 11 cycles opened Unsafe. The most recent program ran from late 2022 to September 2025. Ask what it cost, whether it was funded from reserves or by assessment, and whether any assessment is still running.

Ask about the alteration agreement and the HVAC master plan. This is a landmarked building with a courtyard and two visible elevations. Through-wall air conditioning and window work are governed by Landmarks, and the building appears to operate under a master plan that makes some of that work routine — but only if you follow it.

Confirm the floor and unit counts against the offering plan. City records say twelve floors and sixty apartments; market records say thirteen and about fifty-seven. The offering plan and its amendments will settle it, and they matter if you are buying near the top of the building.

Lead with the Blums and the plan. George and Edward Blum are a name that carries with a well-informed West End Avenue buyer, and the duplex arrangement is a genuinely differentiated product on this corridor. Both facts belong in the first paragraph of the marketing, not the fifth.

Assemble the diligence file before listing. Financing ceiling, sublet policy, post-closing liquidity standard, flip tax basis, the last two years of audited financials, the underlying mortgage maturity and the Cycle 9 façade close-out. Buyers' attorneys will ask for all of it, and a seller who has it ready shortens the contract period materially.

Be direct about the façade cycles. They are in the public record, and a well-advised buyer will find them. Presenting the completed Cycle 9 remediation and the Safe Cycle 10 filing as evidence of a building that maintains its envelope is a stronger position than being asked.

Price by plan, not by line. In a duplex building with decades of combinations, no two apartments are quite the same product. Comparable selection should start from the floor plan and the exposure, then move to the building.

If you're considering 610 West End Avenue, also evaluate:

• 617 West End Avenue — Schwartz & Gross's 1924–25 cooperative directly across the avenue
• 601 West End Avenue — Emery Roth, 1915; the corner cooperative a block south
• 600 West End Avenue — Schwartz & Gross, 1911; the near-contemporary across West 89th Street
• 607 West End Avenue — Rosario Candela, 1926; the corridor's high-design 1920s alternative
• 645 West End Avenue — The Halsworth, Gaetano Ajello, 1912–13; a close contemporary with large prewar layouts
• 639 West End Avenue — The Arbutus, Gronenberg & Leuchtag, 1927; the later prewar alternative
• 650 West End Avenue — Schwartz & Gross, 1917, converted to condominium in 2000; the condominium alternative in the same historic district
• 675 West End Avenue — George F. Pelham, 1925; the larger cooperative two blocks north
• 685 West End Avenue — Sugarman & Berger, 1928; 96 apartments, the large-building alternative
• 590 West End Avenue — Neville & Bagge, 1915; converted from rental in 1988