4 W 21st Street #3-AD
MLS® #RLS20070160
Listing by Nest Seekers LLC
4
Bedrooms
3
Baths
3,000
Sq. Ft.
2006
Year Built
Quick Summary
Property Highlights
- Exposure: North,South facing
- Style: Loft architecture
- Climate Control: Central Air
Property Details
Description
Welcome to Residence 3AD at 4 West 21st Street. A rare, full-floor–scale Flatiron District home offering privacy, flexibility, and long-term versatility. Spanning approximately 3,000 square feet, this thoughtfully combined residence delivers the scale and comfort of a private home with the freedom of condop ownership. With 10-foot ceilings, two separate entryways, and a layout designed to evolve over time, Residence 3AD is equally well-suited for families, co-purchasers, or long-term investors seeking adaptability. A gracious foyer opens to expansive, north-facing living and dining spaces that anchor the home, ideal for daily living, entertaining, or shared use without compromise. The kitchen is connected via a passthrough, maintaining separation while allowing ease of flow, and is complemented by a dedicated dining room and breakfast nook that support everything from weekday mornings to formal gatherings. The south-facing bedroom wing offers four generously proportioned bedrooms, providing exceptional quiet and privacy rarely found in this part of Manhattan. The primary suite functions as a true retreat, complete with a walk-in closet, en-suite bath, and an adjacent office or library, perfect for work-from-home flexibility or future reconfiguration. Designed by acclaimed architect Hugh Hardy, 4 West 21st Street is a boutique, full-service condop that offers the advantages of condo ownership. The building allows pets, unlimited subletting, pied-a`-terres, co-purchasing, gifting, and parents buying for children, making it an ideal choice for multigenerational living, friends buying together through an LLC, or investors seeking maximum flexibility. Amenities include a 24-hour doorman, landscaped common terrace, fitness center, and on-site parking. Located just steps from Madison Square Park, and surrounded by the best of Flatiron, NoMad, and Union Square, residents enjoy immediate access to top dining, culture, and green space, including Eataly, ABC Kitchen, Trader Joe's and more! Private showings available by appointment with The 212Bravo Team at Nest Seekers.
Features & Amenities
Interior Features
Exterior Features
Building Amenities
Building Information
Financial Details
About Flatiron
View All Flatiron ListingsThe Flatiron District is a vibrant intersection of history, technology, and luxury living. Named after the iconic Flatiron Building, the neighborhood is centered around Madison Square Park and is a hub for the city's 'Silicon Alley.' The real estate market is famous for its grand cast-iron loft buildings with high ceilings and expansive floor plans, alongside ultra-luxury glass towers that offer modern amenities and central Manhattan convenience.
Flatiron Live Market Data
View NeighborhoodActive Listings
95
Median Asking Price
$2.75M
Median $/Sqft
$1,787
Avg Days on Market
N/A
New This Week
2
Price Reduced
31%
Sold (30 Days)
7
Median Sale Price
$2.95M
Live data from RLS at REBNY • Updated 2/15/26, 8:55 PM EST
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Location
4 W 21st Street #3-AD, Flatiron, New York County • Near Fifth Avenue/Avenue of the Americas
Virtual Tour
Listing Data
RLS® at REBNY (Real Estate Board of New York) via Trestle API. Updated in real-time.
Market Data
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Map & Location
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Listing Courtesy of Nest Seekers LLC - Isabella Bravo
Listing Contact: (917) 828-4992
Listing information for certain New York City properties provided courtesy of the Real Estate Board of New York's Residential Listing Service (the "RLS"). The information contained in this listing has not been verified by the RLS and should be verified by the consumer. The listing information provided here is for the consumer's personal, non-commercial use. Retransmission, redistribution or copying of this listing information is strictly prohibited except in connection with a consumer's consideration of the purchase and/or sale of an individual property. This listing information is not verified for authenticity or accuracy and is not guaranteed and may not reflect all real estate activity in the market. ©2026 The Real Estate Board of New York, Inc., all rights reserved. This advertisement does not suggest that the broker has a listing in this property or properties or that any property is currently available.
Broker Commission Disclosure: Broker commissions are not set by law and are fully negotiable.
RLS Data display by Keller Williams NYC. Data last updated on 2/16/2026 at 1:55 AM UTC