Open House
Fri, Nov 13 · 12:00PM–1:00PM
Open House
Fri, Nov 13 · 12:00PM–1:00PM
4 W 21ST Street 10D
$1,350,000
MLS# RLS20126001 · Flatiron
Listed November 10, 2026 · New today
2 Beds 3 Baths 1,518 Sq.Ft.
About This Property
Ideally situated in the heart of Flatiron, this spacious 1,518 SF, 2-bedroom, 2.5-bathroom residence at 4 West 21st Street offers loft-like proportions, abundant natural light, and sophisticated finishes in a full-service doorman building.A gracious entry foyer opens into an expansive, sun-drenched great room with floor-to-ceiling windows and electronic shades. Perfect for entertaining, the open layout seamlessly connects the living and dining areas to a chef's kitchen featuring premium Sub-Zero, Miele, Bosch, and Kohler appliances.Both generously sized, south-facing bedrooms enjoy open views and en-suite bathrooms. The primary suite features a large walk-in closet and spa-like bath with heated floors, double vanity, soaking tub, and glass-enclosed shower.Additional highlights include hardwood floors, custom window treatments, in-unit laundry, and a guest powder room.4 West 21st Street is a full-service, pet- and investor-friendly condop offering a 24-hour doorman, fitness center, garage access, and landscaped common garden. Perfectly positioned in the heart of Manhattan, just off Fifth Avenue, with Madison Square Park, Union Square, world-class dining, shopping, and transportation all moments away. Enjoy the convenience of having the best of New York City at your doorstep.Capital Improvement Assessment: $1,076.61/month through June 2027.
Agent's Note
From Curtis Bain. Details about the apartment are drawn from the listing information provided through RLS by Serhant.
Electronic shades run across the floor-to-ceiling windows in the great room, so the light can be adjusted from one place rather than room by room. The great room is where the open layout is most evident, with the living and dining areas flowing into one another.
The kitchen has Sub-Zero, Miele, Bosch and Kohler appliances, and it connects to the living and dining areas, so you'll be cooking in the middle of the room. That suits anyone who likes to host, though it gives up some separation between cooking and everything else. A dishwasher is on the list, and the in-unit washer and dryer mean laundry happens inside the apartment, which I think is one of the more useful everyday conveniences here.
Both bedrooms face south and have en-suite bathrooms. The primary suite adds a walk-in closet, heated floors, a double vanity, a soaking tub and a glass-enclosed shower. For a south-facing window with an open horizon, direct sun runs about 8.5 hours on the winter solstice, from 7:41 AM to 4:07 PM, and about 6.1 hours on the summer solstice, from 9:55 AM to 4:01 PM. Nearby buildings can block that light.
The building has 17 stories and 54 units, was built in 2005, and sits within the Ladies' Mile Historic District. It has a concierge, an elevator, a gym, garage parking, storage and a courtyard, and the listing describes a 24-hour doorman and a landscaped common garden. Pets are allowed. A doorman is handy for deliveries and guests, and it's worth noticing how the lobby and courtyard feel when you visit.
Madison Square Park is about 4 minutes away on foot and Union Square Park about 6 minutes. The 23 St station for the R and W is about 3 minutes, and the F and M at the same stop is about 5 minutes. Trader Joe's is about 4 minutes away, so a regular grocery run stays close.
Quick answers+
Does the apartment have in-unit laundry?
Yes. There's a washer and dryer in the unit.
Does the building have a doorman?
Yes. The building has a 24-hour doorman.
Does the building have an elevator?
Yes. The building has an elevator.

Curtis Bain
Brown Harris Stevens
Property Features
Policies
- Pets allowed
Home features
- Washer/dryer in unit
- City view
- Skyline view
- Dishwasher
- Storage
Building amenities
Services and facilities
- Concierge
- Elevator
- Garage parking
- Laundry in building
- Storage space
Wellness and recreation
- Children's playroom
- Gym
Outdoor space
- Courtyard
Some building amenities are reported on other current listings in this building. Confirm amenities and building policies before relying on them.
Estimate
Monthly Cost & Closing Costs
The rate is a placeholder, not a quote. Enter the one your lender gives you.
$14,541 / month
- Principal and interest$6,826
- Common charges$7,715
Due at closing
- Down payment (20%)$270,000
- NYS “mansion tax” (1%)$13,500
- Mortgage recording tax (1.925%)$20,790
Not included: attorney, title insurance, lender and appraisal fees, board application and move-in fees, flip tax and prepaid items. Estimates only, based on the published New York State rates. Your attorney and lender will confirm the real figures.
About the Building
4 W 21ST Street is a 17-story elevator cooperative in Flatiron, completed in 2005 and home to 54 residential units. It sits within the Ladies' Mile Historic District.
The closest subway is 23 St (R, W), about a 3-minute walk. Madison Square Park is roughly 4 minutes away on foot.
Compiled from NYC public records and open data.
- Year Built
- 2005
- Stories
- 17
- Units
- 54
- Building Type
- Elevator Cooperative
- Historic District
- Ladies' Mile Historic District
Location & Nearby
Map
Loading map…
4 W 21ST Street 10D
Subway
- RW23 StAbout 3 min walk
- FM23 StAbout 5 min walk
- 623 St-Baruch CollegeAbout 7 min walk · Accessible
- 123FLM14 StAbout 8 min walk · Accessible
Parks
- Madison Square ParkAbout 4 min walk
- Union Square ParkAbout 6 min walk
Public schools · Elementary schools
- Ballet Tech, NYC Public School for DanceAbout 4 min walk
- Sixth Avenue Elementary SchoolAbout 6 min walk
- Success Academy Charter School - Union Square · CharterAbout 11 min walk
Middle schools
- New York City Lab Middle School for Collaborative StudiesAbout 15 min walk
- M.S. 255 Salk School of ScienceAbout 16 min walk
High schools
- Manhattan Village AcademyAbout 3 min walk
- The Clinton SchoolAbout 8 min walk
Colleges & universities
- Baruch College (CUNY)About 10 min walk
- Pratt InstituteAbout 11 min walk
- The New SchoolAbout 12 min walk
- Fashion Institute of TechnologyAbout 12 min walk
Museums
- Yeshiva University MuseumAbout 5 min walk
- Poster HouseAbout 6 min walk
- National Museum of MathematicsAbout 9 min walk
- Museum of Food and DrinkAbout 19 min walk
Walking times are estimates. Schools shown are the nearest public and charter schools and are not zone assignments; a nearby school is not necessarily the one an address is zoned for. Confirm zoning with the NYC Department of Education. Sources: MTA, NYC Parks and NYC Department of City Planning open data.
The Neighborhood
About Flatiron
Historic loft architecture meets modern luxury in one of Manhattan's most vibrant and sought-after neighborhoods.
Walkability
10/10
Public transit
10/10
Schools
7/10
Dining
10/10
Groceries & parks
8/10
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Gallery
Property Photos
Listing Courtesy of Serhant
This 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.