235 West End Avenue (The Gemstone)
235 West End Avenue, New York, NY 10023
Lincoln Square, Upper West Side
BBL 1011827501 · BIN 1076239
- Year built
- 1928
- Type
- Condominium
- Units
- 143
- Floors
- 17
- Landmark
- No
- Pets
- Pet-friendly (verify current house rules at offer stage)
- Subletting
- Permitted under the condominium declaration
- Pied-à-terre
- Allowed
Every recorded sale at this building, 2002–2026
Price-per-square-foot over time, the line- and floor-premium curves, and every recorded sale.
- Median $/sf (floor-adjusted)
- $1,126
- Listing discount
- 2.3%
- Recorded sales
- 152
- On record
- 2002–2026
Own an apartment here? See what it would sell for.
A Private Pricing Opinion — what your apartment at The Gemstone 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.
The Gemstone is a Bing & Bing prewar — and that pedigree is the anchor of everything the building offers. The Bing brothers were the most respected apartment-house developers of 1920s Manhattan, and their buildings are prized for the quality of their construction, the generosity of their room proportions, and the discipline of their layouts. What makes 235 West End Avenue distinctive within that body of work is its condominium structure: a prewar Bing & Bing building that trades as a condominium rather than the cooperative form nearly universal among its peers.
That distinction is decisive for a certain buyer. Prewar West End Avenue and Riverside Drive are overwhelmingly cooperative — pedigreed, but governed by board interviews, financing caps, and sublet limits. The Gemstone delivers the prewar architecture, the West End Avenue address, and the Medieval Revival character in a condominium wrapper: financing flexibility, pied-à-terre eligibility, and closings that run on condominium timelines. Prewar bones, condominium mechanics — an uncommon pairing on this stretch of the Upper West Side.
Architecture and unit composition
Bing & Bing's 1928 commission is a seventeen-story Medieval Revival prewar in brick, with limestone and terra-cotta ornament concentrated on the lower stories. The entry is distinguished by stained-glass casement windows, and the lobby carries colorful ceramic-tile detailing on the staircases — the kind of period craftsmanship that defines the building's character.
The residences reflect the building's prewar planning: generous room dimensions, formal layouts, and the solid construction the Bing name implies. The original 184 apartments have, over the decades since the 1987 conversion, been partially combined into roughly 143 units, producing a mix that ranges from prewar one-bedrooms to larger combined layouts. Condition varies line by line with renovation history.
Building operations
The Gemstone operates as a full-service condominium with a 24-hour doorman and a live-in resident manager. Amenities include a fitness center, central laundry, a children's playroom, a landscaped roof deck, and bike storage. The building is pet-friendly.
The 1987 conversion places the building in the wave of prewar rental-to-condominium conversions on the Upper West Side. Common charges and property taxes are consistent with a full-service prewar condominium; buyers should model the full carry at the apartment level and review current financial statements, board minutes, and any reserve study during due diligence.
Local Law 97
- 2024–2029 annual penalty
- $0 (under cap)
- 2030–2034 annual penalty
- $33,767/yr
- Per unit / month range
- $0 – $19
- Modeled exposure split equally across 148 units (the city tax-lot count). Not an assessed amount; co-op shareholders are typically charged by share allocation.
Source: NYC LL84 benchmarking and PLUTO · The Roebling Research Library. City record last verified September 2026.
See full Local Law 97 analysis — emissions history, scenarios, methodology →Facade safety — Local Law 11
The latest available filing classified the facade as SWARMP — Safe With A Repair and Maintenance Program: the engineer identified conditions requiring monitoring or repair, with repairs due by the deadline stated in the filing. The scope, timeline, and how the building funds the work are building-specific — we review the filings and board materials for you.
How to read this, and where it comes from
QEWI = Qualified Exterior Wall Inspector — the licensed engineer the city requires to sign the report (the independent expert, not the managing agent).
Penalties shown are amounts DOB assessed against filings on record across 2005–10 to 2020–25. The FISP dataset does not record whether they were paid, contested or remain open, so treat the figure as history rather than a current balance and confirm the building’s standing with the managing agent.
Source: NYC DOB facade filings (FISP) · The Roebling Research Library. City record last verified September 2026.
Recent sales
The Gemstone trades on the strength of two features that rarely appear together on West End Avenue: prewar Bing & Bing architecture and condominium ownership. Pricing is best read on a price-per-square-foot basis, with the condominium structure itself functioning as a premium input against the cooperative inventory that dominates the corridor. Within the building, value is driven by exposure, floor height, room proportion, and renovation condition. Apartment-level closing detail should be sourced from public records for full transactional context, and pricing should be validated against the most recent comparable sales at the time of offer.
Recent closings 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.
| Date | Unit | Apartment | Price | PPSF | vs. Ask |
|---|---|---|---|---|---|
| Sep 16, 2026 | 3C | 1 BR · 1 BA · 700 sf | $725,000 | $1,036/sf | -14.7% |
| Aug 28, 2026 | 7B | 1 BR · 1 BA · 732 sf | $835,000 | $1,141/sf | -4.6% |
| Apr 8, 2026 | 15E | 1 BR · 1 BA · 678 sf | $850,000 | $1,254/sf | -5.0% |
| Sep 25, 2025 | 8D | 1 BR · 1 BA · 777 sf | $885,000 | $1,139/sf | -6.8% |
| Aug 5, 2025 | 16A | 1 BR · 1 BA · 675 sf | $795,000 | $1,178/sf | +0.0% |
| Aug 12, 2024 | 6J | 2 BR · 2 BA · 1,059 sf | $1,695,000 | $1,601/sf | +0.0% |
| Jul 10, 2024 | 8B | 1 BR · 1 BA · 732 sf | $710,000 | $970/sf | -18.9% |
| Feb 16, 2024 | 4D | 1 BR · 1 BA · 778 sf | $840,000 | $1,080/sf | -4.0% |
Market read. Most recent trades (2026) cleared a median $1,126/sf (floor-adjusted) across 3 sales. 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 2.3% from the last ask — a recurring negotiation gap worth pricing into any offer or listing strategy.
The retrade record
Lines that have traded more than once in the public record — the building’s appreciation arc, apartment by apartment.
Full closing history with price-per-square-foot over time, the complete retrade record, and every line that has traded.
Sales sourced from NYC Department of Finance recorded transfers (BBL 1-01182-7501). 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 from recorded condo declarations and offering plans.
Closed rents at The Gemstone, last 36 months
| Size | Leases | Median / month |
|---|---|---|
| 1 bedroom | 5 | $4,800 |
| 2 bedroom | 3 | $7,300 |
8 closed leases, October 2023 to September 2026. Most recent lease September 2026. Sizes with fewer than 2 leases are not shown. Compiled by The Roebling Team at Compass from closed leases.
At the recent median sale of $835K (5 sales since 2024), a buyer putting 25% down would pay about $31,500 to close, or 3.8% of the price.
- Mansion tax: $0
- Mortgage recording tax: $12,055
- Title insurance: $3,757
- Attorneys, lender, building fees, reserves and filings: $15,687
Assumes a resale (the seller pays transfer taxes), a $4,500 attorney fee and a mortgage on the rest.
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What to know if you’re buying
The Bing & Bing pedigree is real institutional context. The developer's reputation for construction quality and room proportion is a durable value anchor.
Condominium ownership is the differentiator. Financing flexibility, pied-à-terre eligibility, and subletting are governed by the condominium rather than a cooperative board — uncommon for a prewar building on this stretch. Closings run on condominium timelines.
Layout varies with combination history. Because original apartments have been partially combined, room counts and configurations differ meaningfully by line. Verify the specific apartment during walkthrough.
Model the full carry. Common charges plus property taxes plus utilities at the apartment level.
Verify board policy at offer stage. Confirm pet, sublet, and pied-à-terre specifics against the current house rules.
What to know if you’re selling
Lead with prewar-condominium rarity. The pairing of Bing & Bing prewar architecture with condominium ownership is the story that widens the buyer pool beyond what a cooperative peer can reach.
Emphasize the period detail. The stained-glass entry, tiled lobby staircases, and generous room proportions are marketing assets specific to the building.
Pricing requires apartment-level context. Comparable sales vary by line, floor, exposure, and combination history.
Closing timelines are condo-fast. 30 to 60 days from contract to closing.
Comparable buildings
If you're considering 235 West End Avenue, also evaluate:
- 320 West End Avenue — Rosario Candela 1924; nearby West End Avenue prewar peer
- 470 West End Avenue (The Belvoir) — Emery Roth 1928; nearby West End Avenue peer
- 535 West End Avenue — 2011; nearby West End Avenue condominium peer
- 243 West End Avenue (Coliseum Plaza) — Emery Roth 1925; nearby West End Avenue peer
- 100 Riverside Drive — Boak & Paris 1938; nearby Riverside Drive peer
More West End Avenue buildings
- 200 West End Avenue — 2008 condominium by Costas Kondylis & Partners
- 205 West End Avenue (Lincoln Towers) — 1961 condop by S.J. Kessler & Sons
- 230 West End Avenue — 1927 co-op by Rosario Candela
- 240 West End Avenue — 1924 by Rosario Candela
- 243 West End Avenue (Coliseum Plaza) — 1925 co-op by Emery Roth
- Howard House (246 West End Avenue) — 1913 co-op by J.E.R. Carpenter
The neighborhood
For the full corridor — architecture, transit, and pricing across West End Avenue — read The Roebling Team Guide to West End Avenue.
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.
Considering a move at The Gemstone?
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