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$799,000
New Listing

21 Carleton Avenue
East Islip, NY 11730

For Sale|Duplex|Active
4
Beds
2
Total Baths
2
Full Baths
216
SqFt
$3,699
/SqFt
1900
Built
County:
Suffolk
Listing courtesy of Century 21 Monticello Realty patty@monticelloreg.com
Call Now: (631) 727-3713
Is this the listing for you? We can help make it yours.
(631) 727-3713
Upcoming Open Houses
Sat, Sep 26, 1:00 PM - 3:00 PM
Sun, Sep 27, 1:00 PM - 3:00 PM
21 Carleton Avenue21 Carleton Avenue21 Carleton Avenue21 Carleton Avenue
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Mortgage Calculator

Monthly Payment (Est.)

$3,645
Calculator powered by Showcase IDX, a Constellation1 Company. Copyright ©2026 Information is deemed reliable but not guaranteed.

Welcome to East Islip, NY 11730, a beautifully upgraded two-family residence offering generous living space, modern comfort, and an exceptionally convenient location. This well-maintained property is an excellent opportunity for an owner-occupant, investor, or buyer seeking flexible living arrangements with the benefit of two separate units. The spacious first-floor unit features three comfortable bedrooms and a bright, inviting layout designed for everyday living and entertaining. The second-floor unit offers one bedroom with its own private living space, making it ideal for rental income, guests, or additional household needs. The home has been fully upgraded, allowing the next owner to move in and enjoy its many improvements. For added comfort and efficiency, the property is equipped with two separate boilers and five energy-efficient split HVAC units, providing flexible heating and cooling throughout the home. A large private driveway can accommodate up to six vehicles, a valuable feature for a two-family property. Conveniently located approximately 10 minutes from the Long Island Rail Road, this home provides an easy commute to New York City and surrounding Long Island communities. It is also close to major roadways, shopping malls, supermarkets, restaurants, local stores, schools, parks, and other everyday necessities. With its upgraded condition, separate living spaces, modern heating and cooling systems, generous parking, and convenient East Islip location, offers an outstanding combination of comfort, convenience, and income-producing potential. Don’t miss the opportunity to own this versatile two-family home in one of Long Island’s desirable communities. Schedule your private showing today!

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Listing Snapshot
Price 
$799,000
Days On Site 
0 Days
Bedrooms 
4
Inside Area (SqFt) 
216 sqft
Total Baths 
2
Full Baths 
2
Partial Baths 
N/A
Lot Size 
0.15 Acres
Year Built 
1900
MLS® Number 
1052970
Status 
Active
Property Tax 
$12,517
HOA/Condo/Coop Fees 
N/A
Sq Ft Source 
N/A
Friends & Family
Recent Activity
21 hours agoListing first seen on site
21 hours agoListing updated with changes from the MLS®
General Features
Acres 
0.15
Garage 
Yes
Parking 
Driveway
Parking Spaces 
6
Property Sub Type 
Duplex
Sewer 
Public Sewer
SqFt Total 
216
Utilities 
Natural Gas AvailableCable ConnectedElectricity ConnectedNatural Gas Connected
Water Source 
Public
Interior Features
Basement 
Finished
Cooling 
Ductless
Heating 
Hot Water
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Exterior Features
Construction Details 
Frame
Community Features
School District 
East Islip
Schools
School District
East Islip
Elementary School
John F Kennedy Elementary School
Middle School
East Islip Middle School
High School
East Islip High School
Listing courtesy of Century 21 Monticello Realty patty@monticelloreg.com


Based on information submitted to the MLS GRID as of 2026-09-20 08:10 AM EDT. All data is obtained from various sources and may not have been verified by broker or MLS GRID. Supplied Open House Information is subject to change without notice. All information should be independently reviewed and verified for accuracy. Properties may or may not be listed by the office/agent presenting the information.

Neighborhood & Commute
Source: Walkscore
Disclosure: Community information and market data powered by Constellation Data Labs. Information is deemed reliable but not guaranteed.
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