For Sale · Listing by Douglas Elliman Real Estate
879 UNION Street
Park Slope, Brooklyn
$4,250,000
$4,250,000
879 UNION Street
MLS® #RLS20095182
Listing by Douglas Elliman Real Estate
- 7
- Bedrooms
- 6
- Baths
- N/A
- Sq. Ft.
- 1920
- Year Built
Quick Summary
Property Highlights
- Views: Other
- Character: Pre-war building (1920)
Property Details
Listing History
| Event | Date | Price | Change |
|---|---|---|---|
| Listed | Jun 2, 2026 | $4,250,000 | - |
| Currently | Oct 20, 2026 | $4,250,000 | - |
Description
Nestled on one of Park Slope's most picturesque, treelined blocks, 879 Union Street presents a rare opportunity to own a grand 21 foot wide brownstone that seamlessly blends historic charm with exceptional flexibility and income potential. Built in 1885 and spanning approximately 4,030 square feet, this stately residence is configured as a 5 unit property, offering both an expansive owner's home and strong rental performance in one of Brooklyn's most desirable neighborhoods. For the end user, the garden duplex delivers a true brownstone lifestyle - thoughtfully scaled with 3 bedrooms, 2 baths, and a private deck that opens to a generous landscaped garden. Rich prewar details - including original woodwork, tall windows, hardwood floors, and soaring ceilings - create a warm, inviting atmosphere that is both timeless and livable. The home is further enhanced by private access to the cellar, adding valuable bonus space for storage, recreation, or customization to suit your needs. For the developer or investor, the property offers substantial upside. Configured with 4 free market rental units above the owner's duplex, the building provides immediate income with long term growth potential. Its rare 21' x 48' footprint allows for a range of strategic possibilities - whether optimizing the current rental mix, upgrading finishes, or reimagining the layout to maximize value. In addition, the property benefits from ample unused air rights, presenting a compelling opportunity for expansion and further value creation. The combination of scale, width, and development potential is increasingly difficult to find, making this a uniquely adaptable asset in a supply constrained Park Slope market. Positioned between 7th and 8th Avenues, just moments from Prospect Park, Grand Army Plaza, and some of Brooklyn's best dining, shopping, and transportation, 879 Union Street offers the perfect balance of tranquility and connectivity. Whether envisioned as a luxurious primary residence with rental income, a multigenerational home, or a high-performing investment property, this is a rare chance to acquire a premier Park Slope brownstone with both immediate appeal and lasting upside. You should live here!
Features & Amenities
Interior Features
Exterior Features
Building Amenities
Building Information
Financial Details
About Park Slope
View All Park Slope ListingsPark Slope is a well-known Brooklyn neighborhood, recognized for its tree-lined streets and preserved brownstones. Bordering the western edge of Prospect Park, the neighborhood offers convenient access to green space. The real estate market features a mix of historic townhouses, cooperatives, and modern condominiums, within walking distance of the park.
Park Slope Live Market Data
View NeighborhoodActive Listings
100
Median Asking Price
$1.70M
Median $/Sqft
$1,334
Avg Days on Market
N/A
New This Week
4
Price Reduced
13%
Sold (30 Days)
26
Median Sale Price
$1.69M
Live data from RLS at REBNY • Updated 10/20/26, 8:30 AM EST
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Location
879 UNION Street, Park Slope, Kings County
Floor Plans
Building Information
Official NYC property records for this building
Tax & Assessment
Note: Individual unit taxes may differ. Verify current tax bills with NYC DOF.
Source: NYC PLUTO (Primary Land Use Tax Lot Output), NYC Department of City Planning (data.cityofnewyork.us)
Want help estimating ownership costs or understanding building compliance? Let's discuss
Listing Data
RLS® at REBNY (Real Estate Board of New York) via Trestle API. Updated in real-time.
Building Data
NYC PLUTO (Primary Land Use Tax Lot Output), NYC Department of City Planning. Updated quarterly.
Market Data
RLS® at REBNY (Real Estate Board of New York). Live data updated in real-time.
Map & Location
OpenStreetMap contributors via Leaflet. Geocoding via Nominatim.
All data is provided for informational purposes only and should be independently verified. See our Data Sources Policy for more information.
Frequently Asked Questions
Common questions about this property
The current listed annual property tax is $25,344, or roughly $2,112 per month. Verify the current assessment with your attorney before closing.
This property has 7 bedrooms and 6 full bathrooms.
According to MLS records, the building was constructed in 1920, making it approximately 106 years old.
This listing is None
Pets are permitted at this property. Contact Milton Coste for weight limits or breed restrictions.
To schedule a private showing, contact Milton Coste at (917) 416-7433 or [email protected]. Per REBNY guidelines effective 2025, a Buyer Representation Agreement is required before a buyer's broker can show you properties. You may attend open houses independently without one.
Have a question not answered here?
(917) 416-7433Listing Courtesy of Douglas Elliman Real Estate - Terry S Robison
Listing Contact: (917) 482-4812
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.
How working with a buyer's agent works: I work for you, not the seller. Before I show you anything, New York brokerage rules ask us to put that in writing: an agreement and a disclosure that say I work for you and negotiate on your behalf. The agreement is non-exclusive: you can work with other agents, it runs for a short fixed term we agree on, and you can end it with a note. You may attend open houses independently without an agreement. Read how it works
RLS Data display by Keller Williams NYC. Data last updated on 10/20/2026 at 12:30 PM UTC
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Sale history, taxes, violations and comps for this unit
Before you bid
Pre-Offer Report: 879 UNION Street
At $4,250,000, the listing leaves out what decides the offer: the recorded sale history, the tax and abatement picture, open building violations and permits, and the closed sales that set the price. Milton prepares the report from public records. No obligation.
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What happens next
- 1Milton emails you today.
- 2A short call about what you want and when.
- 3The agreement arrives electronically after the call. Then showings.
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You're contacting Milton Coste, a buyer's agent. Before any private showing, New York brokerage rules require a short non-exclusive agreement. Milton walks you through it before you sign anything. Broker commissions are not set by law and are fully negotiable. How working together works.
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Quick Facts
Monthly Costs Estimate
$850,000
Source: Freddie Mac PMMS
Est. Monthly Payment
$0
Estimates only. Consult a lender for exact figures.
Mansion tax applies at this price point
New York State charges the buyer a mansion tax on residential purchases at $1,000,000 or more. At this asking price the tier is $3M to $4,999,999 at 1.50%, applied to the whole purchase price. It is due in cash at closing and cannot be financed.
Estimated mansion tax at asking
$63,750
Estimate based on the asking price. Confirm your own obligation with your real estate attorney.
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