- Year built
- 1960
- Type
- Condominium
- Units
- 128
- Floors
- 13
- Landmark
- No
- Pets
- Pet-friendly for resident owners, subject to approval
Every recorded sale at this building, 2004–2026
Price-per-square-foot over time, the line- and floor-premium curves, and every recorded sale.
- Median $/sf
- $898
- Listing discount
- 3.6%
- Recorded sales
- 88
- On record
- 2004–2026
The Hardenbrook House is a full-service postwar condominium in the far-east reach of Lenox Hill — a 1960 building on the quiet mid-block stretch of East 66th Street between First and York Avenues, close to the East River, the hospital corridor, and the tram and bridge approaches. Condominium ownership is comparatively uncommon in this pocket of the Upper East Side, where postwar inventory skews heavily to cooperatives. That distinction is the building's central value proposition: it offers the flexibility of condo ownership — straightforward financing, permissive subletting, and pied-à-terre use — in a neighborhood where those terms are otherwise scarce.
The appeal is practical rather than architectural. This is a service-forward, amenity-equipped building with an attended garage, a live-in super, and a landscaped courtyard, historically carrying common charges that run lower than many comparable full-service buildings in the immediate area. For buyers who want an owner-occupied home, a pied-à-terre, or an income-producing hold without the constraints of a co-op board, the Hardenbrook House is one of the more usable options east of Second Avenue.
Recent sales
As a condominium, 404 East 66th Street trades on a price-per-square-foot basis rather than the price-per-room framing used for co-ops. Pricing here reflects three durable factors: the far-east Lenox Hill location, which sits at a discount to the Park-and-Fifth blocks; the condominium tenure, which typically commands a premium over comparable co-op stock because of financing and subletting flexibility; and the building's postwar layouts, which favor efficient studio-through-two-bedroom configurations over grand prewar proportions.
Buyers should expect per-square-foot values below the trophy condominium corridor and generally in line with, or modestly above, the full-service co-op inventory nearby — with the condo structure and permissive subletting supporting resale liquidity and investor demand. Specific closed prices move with unit line, floor, light, and condition, and should be underwritten against current recorded transfers rather than headline averages.
Recent closings at this building, curated by The Roebling Team research desk. Apartment-level facts are independently verified before publishing; sale prices reflect the recorded transfer amount at the NYC Department of Finance.
| Date | Unit | Apartment | Price | PPSF | vs. Ask |
|---|---|---|---|---|---|
| Mar 16, 2026 | 1G | 1 BR · 1 BA · 877 sf | $770,000 | $878/sf | -3.1% |
| May 21, 2025 | 7C | 500 sf | $620,000 | $1,240/sf | -4.5% |
| Mar 11, 2025 | 2B | 1 BA · 560 sf | $560,000 | $1,000/sf | off-mkt |
| Feb 28, 2025 | 3H | 874 sf | $650,000 | $744/sf | off-mkt |
| Dec 18, 2024 | 2A | 1 BR · 1 BA · 721 sf | $690,000 | $957/sf | -5.3% |
| Oct 21, 2024 | 6H | 1 BR · 1 BA · 875 sf | $795,000 | $909/sf | -11.2% |
| Sep 20, 2024 | 4D | $3,702,534 | off-mkt | ||
| Jun 28, 2024 | 4N | 1 BR · 1 BA · 700 sf | $700,000 | $1,000/sf | -7.9% |
Market read. Most recent trades (2026) cleared a median $898/sf across 1 sale. Median listing discount 3.6% 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 1-01460-7501) 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
- Condominium tenure is the headline advantage. Financing flexibility, pied-à-terre use, and permissive subletting are rare in this pocket of Lenox Hill and directly support the building's resale and rental utility.
- Amenities are service-forward, not resort-style. Attended garage, live-in super, central laundry, bike room, storage, and a landscaped courtyard — but no roof deck, gym, or pool on record.
- Common charges have historically run lower than many full-service peers; confirm current charges, assessments, and the reserve position in the financials.
- The far-east location is a trade-off. Quiet and residential, close to the river and the hospital corridor, but a longer walk to the Lexington Avenue subway lines than blocks farther west.
- Confirm the unit count and any active assessments against the offering plan and current schedule at diligence, since public sources differ.
What to know if you’re selling
- Lead with the condominium structure. In a co-op–dominated micro-market, financing flexibility and subletting rights are a genuine differentiator worth foregrounding.
- Position the amenity package clearly — attended garage, live-in super, storage, and courtyard — while setting accurate expectations on the absence of a roof deck, gym, or pool.
- Bring current financials to the table. Historically competitive common charges are a selling point when documented against neighboring buildings.
- Pricing should be anchored to recent in-building and immediate-block comparables, with condition and floor/light adjustments, rather than to broader Lenox Hill averages.
Comparable buildings
- 304 East 65th Street (The Rio) — nearby Lenox Hill condominium with full amenity package
- 310 East 70th Street — nearby full-service Lenox Hill cooperative
- 1440 Second Avenue — nearby full-service Lenox Hill cooperative
- 188 East 76th Street — nearby Upper East Side peer
- 1 East 66th Street — same cross-street Upper East Side peer
The Roebling Team at The Hardenbrook House Condominium
The Roebling Team specializes in Upper East Side transactions, with particular depth in Lenox Hill's postwar condominium and cooperative inventory. We track pricing, policy, and closing detail building by building, and we bring that granularity to both buyers and sellers at 404 East 66th Street. If you are weighing a purchase or a sale here, we can walk you through the current picture and how this building compares to its immediate peers.
The neighborhood
For the full corridor — architecture, schools, transit, and pricing across Upper East Side — read The Roebling Team Guide to Upper East Side.
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