520 Park Avenue

The principal residences distribute across the 54-story tower with substantial floor plates. Standard apartments run about 4,600 sf; the smallest configurations are simplex apartments at the lower tower; the largest include multi-floor penthouses exceeding 12,000 sf at the building's top, including the substantial $130M penthouse that has been part of the building's marketing history.

Stern's pre-war-classical signatures throughout: 11–12 foot ceilings in primary rooms, formal entry galleries with grand proportions reminiscent of Candela/Cross & Cross original detail, library-living-room combinations, primary suites with substantial closet and dressing infrastructure, formal dining rooms with full butler's pantries, service wings — the same architectural vocabulary that the Park Avenue pre-war cooperatives across the street pioneered in the 1920s and 1930s, executed with modern building systems.

The Indiana limestone exterior is visible from within many apartments as a defining architectural surface; floor-to-ceiling glass is available on primary exposures in some configurations. View altitude is exceptional — apartments at the upper end of the 781-foot tower command unobstructed sight lines across Central Park (looking north), the East River and Queens (looking east), the Empire State Building and downtown (looking south).

Sponsor offering structure (per Schedule A)

The original sponsor offering distributed the building's residential inventory across four distinct tiers, each with a structurally different financial profile:

Standard residential units (approximately 30 apartments, floors 6 through ~37). Configured almost universally as 4 BR / 5.5 BA at 4,613–4,628 sf with a fixed Common Interest of 2.4613–2.4693% per unit. Sponsor pricing rose with floor altitude across the standard band. Projected first-year monthly carry (common charges + real estate taxes only, excluding utilities and insurance): approximately $17,385–$17,442 per month ($209,000/year). The remarkable consistency in unit configuration across the standard band — almost every unit being the same 4 BR / 5.5 BA / 4,613 sf layout — is a defining feature of the building and meaningfully distinguishes 520 Park from supertall peers (where unit configurations vary substantially floor-by-floor).

Duplex Penthouses (DP-PH 38, 40, 42, 44, 46, 48 — 6 units). Configured as 6 BR / 7.5 BA at 9,138 sf with 475 sf private terraces. Common Interest 4.8756% per unit. Projected monthly carry: approximately $34,439 per month ($413,000/year).

Triplex Penthouse (TRI-PH 52 — the top of the building). Configured as 8 BR / 9.5 BA at 12,394 sf with 1,259 sf terrace. Common Interest 7.2846%. Projected monthly carry: approximately $51,455 per month ($617,000/year). This was the building's marquee residence and shaped the building's marketing identity through the 2017–2019 sponsor sales window.

Suite Units (7 units). Small 0/1 BR studio-scale units sized approximately 250–325 sf. These units are structurally distinct from the main residences and were marketed for staff residences, nanny suites, guest accommodations, or office use by primary unit owners. Suite Units carry materially lower common interest percentages (~0.21% each) and correspondingly lower carrying costs (~$1,460–$1,617/month).

Storage Units (12 separately offered) and Wine Storage Lockers (9 separately offered) are sold as standalone condominium units, not as common elements — a structuring choice that allows resident-owners to acquire dedicated storage and wine storage with proper deed interests.

Resident Manager's Unit (Unit 5B). The condominium's resident manager occupies a dedicated unit (5B) that is owned by the Condominium Board on behalf of all unit owners. Each Standard Residential Unit, Duplex Penthouse, and Triplex Penthouse owner contributes their pro-rata share of the Resident Manager's Unit acquisition cost ($110,307 share for Standard Residential units; $218,509 share for Duplex Penthouses) at closing — a structurally important detail that buyers should understand as part of their total closing costs.

Aggregate offering scale:

The $1.22 billion grand total places 520 Park among the larger single-building condominium offerings in Manhattan history — though materially smaller than 432 Park's $3.13 billion aggregate.

First-year real estate tax projections: Approximately $4.0–5.0 million aggregate across all units, based on the partially constructed assessment ($18.9M transitional valuation for the first 3 months of 2016/17 tax year) transitioning to a fully constructed assessment. Real estate tax rate: $13.145 per $100 of assessed valuation (2016–17 / 2017–18).

Closing cost note: Each purchaser pays a non-refundable Working Capital Fund contribution at closing equal to 2 months of common charges — typical for new-construction condominiums. On a Standard Residential Unit, this represents approximately $14,850 in addition to standard closing costs. On a Duplex Penthouse, approximately $29,330. On the Triplex Penthouse, approximately $43,820.

Pool availability timing: Per the offering plan, the swimming pool in the fitness center may not be available for use until approximately 24 months after the First Closing — a typical new-construction condominium pacing note (other amenities may not be available for ~12 months post-first-closing).

520 Park operates as a luxury condominium with full-time doorman, 24-hour concierge, valet parking, and the broader amenity package. The amenity program is substantial — fitness center, pool, spa, residents' lounge, private dining and conference space, screening room, library — though deliberately not as expansive as the largest modern supertalls (Central Park Tower's 50,000 sf or 53W53's 17,000 sf Wellness Center). 520 Park's amenity posture is more institutional and quieter, consistent with the building's pre-war-styled architectural argument.

Common charges and property taxes are substantial — and per the building's offering plan Schedule A, the first-year projected carry varies materially by unit tier: Standard Residential (4 BR / 4,613 sf) carries approximately $17,385/month all-in (common charges + RE tax, excluding utilities); Duplex Penthouses (9,138 sf, floors 38–48) approximately $34,439/month; the Triplex Penthouse (12,394 sf, top of building) approximately $51,455/month. Add electric (separately metered or potentially bulk-rated through the Condominium Board), insurance, and parking fees on top of the Schedule A base. Subsequent years have escalated from these 2017–2018 baselines.

The 2018 completion places 520 Park at the most recent end of the pre-war-styled trophy condominium corpus alongside 220 CPS (also 2018 and also Stern-designed, though developed by Vornado Realty Trust rather than Zeckendorf). Buyers should review current building engineering reports, the budget and audited statements during due diligence.

Recent sales

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.

Market read. Most recent trades (2026 to date) cleared a median $2,515/sf (recorded) across 1 sale. Median listing discount 15.4% 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 1-01375-7504; each condominium apartment is its own tax lot). 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.

The Stern + Zeckendorf pedigree is real. 15 Central Park West and 520 Park Avenue share the same developer and architect; 220 Central Park South shares the architect but was developed by Vornado Realty Trust. The architectural and operational continuity is meaningful.

Review current inventory and recent transfers. A small principal-residence count does not establish purchaser composition, slower turnover or a multi-month search period.

Indiana limestone cladding is a real differentiator. At 781 feet, 520 Park is a tall, slender residential tower rather than a supertall (the international benchmark is 984 feet). Its full Indiana limestone cladding is less common than the glass and precast facades of most modern Manhattan towers and is central to Robert A.M. Stern Architects' design; 220 Central Park South is the closest limestone-clad peer.

Apartment scale approaches pre-war full-floor configurations. Standard apartments of about 4,600 sf and penthouses of 9,100–12,400 sf are substantially larger than typical modern condominium apartments. Buyers should evaluate apartments at this scale rather than indexing against 1,500–3,000 sf supertall standards.

Documented condominium policies. Pied-à-terre use and leasing by owners are permitted; confirm foreign-buyer and investment-use rules and closing timing in the declaration, bylaws and house rules.

Mansion tax cliff effects routinely apply. At 520 Park pricing, multiple cliff thresholds ($5M, $10M, $15M, $20M, $25M) apply. Run pricing through the Mansion Tax Calculator.

Marketing should emphasize the pre-war-styled architectural posture. Listing copy should reference Stern's RAMSA practice, the Indiana limestone, the Zeckendorf development team, and the building's continuity with 15 CPW and 220 CPS as the modern pre-war-styled condominium canon.

Pricing requires apartment-level context. The principal-apartment inventory is small (35 apartments in the architect's 2019 account; confirm the current schedule against the offering plan and amendments); comparable analysis at the apartment-configuration level is critical given the substantial variation.

Closing timelines vary. There is no co-op board interview; timing depends on the condominium's right-of-first-refusal process, financing and the contract.

If you're considering 520 Park Avenue, also evaluate:

• 15 Central Park West — Stern 2008; same development team; CPW positioning
• 220 Central Park South — Stern 2018; same architect, developed by Vornado; Central Park South tower
• 432 Park Avenue — Viñoly 2015; pure-residential supertall
• One57 — de Portzamparc 2014; mixed-use with Park Hyatt
• 111 West 57th (Steinway Tower) — SHoP 2021; thinnest skyscraper
• 740 Park Avenue — pure-residential pre-war Park Avenue tier-one
• 720 Park Avenue — Candela 1929; comparable Park Avenue intimacy