39 West 23rd Street
39 West 23rd Street, New York, NY 10010
Flatiron
BBL 1008257502 · BIN 1091569
- Year built
- 2018
- Type
- Condominium
- Landmark
- No
Every recorded sale at this building, 2022–2026
Price-per-square-foot over time, the line- and floor-premium curves, and every recorded sale.
- Median $/sf
- $2,182
- Listing discount
- 2.4%
- Recorded sales
- 56
- On record
- 2022–2026
Own an apartment here? See what it would sell for.
A Private Pricing Opinion — what your apartment at Flatiron House 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.
39 West 23rd Street, known as Flatiron House, is a 2018 condominium developed by Anbau and designed by COOKFOX Architects — the firm celebrated for its biophilic, garden-integrated approach to New York design. The building's defining gesture is its plan: it spans the full block from West 23rd to West 24th Street as two distinct structures linked by a planted garden and an architectural glass walkway, a configuration that brings light, air, and greenery into the heart of a dense Flatiron block. The result is a building that feels more connected to nature than its address would suggest, which is precisely the COOKFOX signature.
The location is the supporting argument. Flatiron House sits half a block from Madison Square Park — one of Manhattan's finest small parks — putting residents within steps of the neighborhood's celebrated restaurants, galleries, museums, and transit. The Flatiron and NoMad blocks around it are among the most dynamic in the city, blending pre-war commercial architecture with a wave of design-driven residential development, of which Flatiron House is a leading example.
For buyers, the proposition is COOKFOX-designed, garden-integrated new construction near Madison Square Park, with a full amenity suite and the ownership flexibility of a condominium, in a 44-unit building of real architectural distinction.
Architecture and unit composition
COOKFOX's design is the building's argument. The two-building, garden-linked plan — connected by a glass walkway — is unusual for a Manhattan block and delivers the firm's hallmark integration of light, air, and planting. The contemporary façades and the central garden give the building a calm, green presence that distinguishes it from conventional infill development, and the design takes its cues from the Madison Square North context around it.
The 44 residences span twenty-five stories across the two linked structures, with layouts from efficient homes to larger family residences and the upper-floor apartments that capture the building's best light and outlooks toward Madison Square Park and the surrounding skyline. New construction here means contemporary ceiling heights, modern systems, and the light-conscious layouts and finishes of a high-end 2018 building, with garden-facing and upper-floor lines the most sought-after.
Building operations
Flatiron House runs as a full-service condominium with a deep amenity program: an attended lobby, a fitness center with an adjacent terrace, the central planted garden, a residents' lounge, a game room, bike storage, supplemental laundry, and private storage available for purchase. The garden is the standout — a genuine outdoor amenity that anchors the building's design and daily life. Common charges reflect that staffing and the amenity roster; real estate taxes are billed per unit in the standard condominium structure.
The condominium format gives buyers the flexibility the neighborhood expects. Financing is flexible, purchases clear through a right-of-first-refusal rather than a board interview, and pied-à-terre, trust, LLC, and investment ownership are customary — well suited to the design-minded, international, and part-time-resident buyers Flatiron and NoMad attract. Subletting and pet specifics follow the condominium's governing documents and are confirmed through the managing agent.
Local Law 97
- 2024–2029 annual penalty
- $0 (under cap)
- 2030–2034 annual penalty
- $0 (under cap)
- Per unit / month range
- —
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 →Management & transfer contacts
- Notable fees
- Working capital contribution equal to 2 months common charges; homeowner's insurance required ($3M total coverage)
Recent sales
Recent closings at this building, curated by The Roebling Team research desk. 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 |
|---|---|---|---|---|---|
| Aug 18, 2026 | PH20 | 4 BR · 4 BA · 3,194 sf | $9,800,000 | $3,068/sf | -10.9% |
| Jul 24, 2026 | 7A | 2 BR · 2.5 BA · 1,607 sf | $3,475,000 | $2,162/sf | -0.7% |
| Jul 13, 2026 | 8B | 1 BR · 1.5 BA · 1,052 sf | $1,825,000 | $1,735/sf | -6.2% |
| May 11, 2026 | PH | 3 BR · 3.5 BA · 3,228 sf | $12,000,000 | $3,717/sf | -4.0% |
| Mar 3, 2026 | 17A | 3 BR · 3 BA · 1,944 sf | $4,995,000 | $2,569/sf | +0.0% |
| Aug 8, 2025 | — | 2,908 sf | $6,601,289 | $2,270/sf | off-mkt |
| Aug 8, 2025 | — | 2,908 sf | $6,601,288 | $2,270/sf | off-mkt |
| Aug 1, 2025 | TH1Sponsor Sale | 4 BR · 3.5 BA · 2,908 sf | $6,600,500 | $2,270/sf | -2.2% |
Market read. Most recent trades (2026) cleared a median $2,182/sf across 3 sales. Median listing discount 2.4% 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 1-00825-7502) 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; square footage from recorded condo declarations and offering plans.
What to know if you’re buying
The case for buying here is COOKFOX design and greenery near Madison Square Park. You are buying into a building organized around a planted garden, designed by one of the city's most thoughtful firms, with a full amenity suite and the ownership flexibility of a condominium, half a block from one of Manhattan's best parks. The trade-offs are that outlook and light vary across the two linked structures and twenty-five stories, so the specific residence — its building, its floor, its relationship to the garden and the park — is what to evaluate closely. For the design-forward buyer who wants light, air, greenery, and a central Flatiron location with full-service condominium living, the building is a standout.
What to know if you’re selling
A resale at Flatiron House markets on its design and its setting: COOKFOX, the garden-linked plan, the glass walkway, and the proximity to Madison Square Park are durable differentiators that distinguish a home here from conventional Flatiron inventory. The condominium structure widens the buyer pool to design-minded, international, and pied-à-terre purchasers and delivers a faster closing through a right-of-first-refusal. Pricing belongs against the newest Flatiron and NoMad condominium set, with floor level, light, and garden or park outlook driving the spread; garden-facing homes should be marketed on that private, green advantage. Presentation should let the design and the greenery lead. Marketing to the design-literate, flexibility-minded buyer the neighborhood attracts is the path to a strong sale.
Comparable buildings
If you're evaluating 39 West 23rd Street, these nearby Flatiron, NoMad, and Madison Square Park condominiums make a useful comparison set:
- 225 Fifth Avenue — Madison Square Park condominium
- 212 Fifth Avenue — pre-war condominium conversion at Madison Square Park
- 262 Fifth Avenue — NoMad / Flatiron condominium
- 277 Fifth Avenue — NoMad condominium tower
- 1107 Broadway — the 2015 condominium
- 141 Fifth Avenue — Flatiron pre-war condominium
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 Flatiron House?
Request a private building brief with the relevant comparable sales, current and off-market availability, and an apartment-specific view of value.