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Off market
  • $10,268,400

    20 Union St, Sag Harbor, NY 11963

    6beds
    5,900sqft
    Single Family Residence
    Built in 1796
    0.34 Acres Lot
    $10,268,400 Zestimate®
    $1,740/sqft
    $191,201 Estimated rent

    Home value

    $10,268,400

    $7.50M - $13.76M

    $191,201/mo

    Zestimate® history
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    What's special

    Gunite poolAmazing landscapingLibrary with fireplaceElegant terracesWine cellar

    Once the "Summer White House" for President Chester A. Arthur, this three A­story Victorian Mansion has been completely renovated and redesigned by renowned designer Steven Gambrel. Located on a private and secluded .34 of an acre property, it features a Gunite Pool, elegant terraces, amazing landscaping, and even your own garage and parking spot. Over the last three years, this sixA­bedroom home underwent a complete renovation and has emerged as an immaculate home for a luxurious lifestyle, all while still retaining the elegant and historic character. The main floor includes a library with fireplace, formal dining and living room with stunning antique fireplace, kitchen and family room with fireplace overlooking the garden and pool. The six bedrooms are spread out on the second and third floors offering beautiful views over the historic village of Sag Harbor. One can find a media room with a fireplace and a wine cellar in the finished basement. Both house and garden have a Sonos Audio System and invite for beautiful entertaining. . the most spectacular residences so close to the restaurants and harbor. Ask us about the additional option of a staf/guest house down the street. Spectacular opportunity.

    This property is off market, which means it's not currently listed for sale or rent on Zillow. This may be different from what's available on other websites or public sources.

    Zillow last checked:

    Source: Out East,MLS#: 36176

    Facts & features

    Interior

    Bedrooms & bathrooms
    • Bedrooms: 6
    • Bathrooms: 5
    • Full bathrooms: 4
    • 1/2 bathrooms: 1
    Cooling
    • Central Air
    Features
    • Has basement: No
    • Has fireplace: Yes
    Interior area
    • Total structure area: 5,900
    • Total interior livable area: 5,900 sqft

    Property

    Parking
    • Parking features: GarageDetached
    • Has garage: Yes
    Features
    • Stories: 3
    • Has private pool: Yes
    • Pool features: Heated
    Lot
    • Size: 0.34 Acres
    Details
    • Parcel number: 0903003000300067000

    Construction

    Type & style
    • Home type: SingleFamily
    • Property subtype: Single Family Residence
    Condition
    • New construction: No
    • Year built: 1796

    Community & neighborhood

    Location
    • Region: Sag Harbor

    Price history

    DateEventPrice
    10/8/2025Listing removed$12,995,000$2,203/sqft
    Source: Out East #36176 Report a problem
    7/30/2025Pending sale$12,995,000$2,203/sqft
    Source: Out East #36176 Report a problem
    7/30/2025Listing removed$12,995,000$2,203/sqft
    Source: Out East #36176 Report a problem
    7/29/2025Pending sale$12,995,000$2,203/sqft
    Source: Out East #36176 Report a problem
    11/7/2024Price change$12,995,000-3.7%$2,203/sqft
    Source: Out East #36176 Report a problem
    9/20/2021Price change$13,495,000-2.2%$2,287/sqft
    Source: Douglas Elliman #109514 Report a problem
    6/20/2021Price change$13,800,000-1.4%$2,339/sqft
    Source: Douglas Elliman #109514 Report a problem
    9/22/2020Listing removed$350,000$59/sqft
    Source: Bridgehampton #66705 Report a problem
    9/21/2020Listed for rent$350,000+950%$59/sqft
    Source: Bridgehampton #66705 Report a problem
    9/30/2019Price change$14,000,000+3.7%$2,373/sqft
    Source: Douglas Elliman Real Estate #109514 Report a problem
    9/30/2019Listing removed$33,333$6/sqft
    Source: Bridgehampton #66705 Report a problem
    9/23/2019Listed for rent$33,333-44.4%$6/sqft
    Source: Bridgehampton #66705 Report a problem
    11/26/2018Listed for sale$13,500,000-4.9%$2,288/sqft
    Source: Douglas Elliman Real Estate #109514 Report a problem
    11/26/2018Listing removed$60,000$10/sqft
    Source: Douglas Elliman Real Estate Bridgehampton Office #66705 Report a problem
    11/5/2018Price change$60,000-52%$10/sqft
    Source: Douglas Elliman Real Estate Bridgehampton Office #66705 Report a problem
    10/24/2018Price change$125,000+13.6%$21/sqft
    Source: Douglas Elliman Real Estate Bridgehampton Office #66705 Report a problem
    10/17/2018Listed for rent$110,000$19/sqft
    Source: Douglas Elliman Real Estate Southampton Office #66705 Report a problem
    11/2/2017Listing removed$14,200,000$2,407/sqft
    Source: The Corcoran Group #36176 Report a problem
    8/3/2016Listed for sale$14,200,000+305.7%$2,407/sqft
    Source: Douglas Elliman #H33799 Report a problem
    3/3/2014Sold$3,500,000-10.3%$593/sqft
    Source: Public Record Report a problem
    1/26/2014Listed for sale$3,900,000$661/sqft
    Source: Sotheby's International Realty - #0037182 Report a problem

    Public tax history

    YearProperty taxesTax assessment
    2025-- $9,674,100
    2024-- $9,674,100
    2023-- $9,674,100 -0.1%
    2022-- $9,684,500
    2021-- $9,684,500
    2020-- $9,684,500
    2019-- $9,684,500 +77.6%
    2018-- $5,451,800
    2017$29,937 $5,451,800 0%
    2016-- $5,453,400 +228.8%
    2015-- $1,658,600 +20.7%
    2014-- $1,373,700
    2013-- $1,373,700
    2012-- $1,373,700
    2011-- $1,373,700
    2007$6,936 -9.7%$1,373,700 +17.8%
    2005$7,679 -23.9%$1,165,726 +4608.1%
    2004$10,086 +8.4%$24,760
    2003$9,306 +10.4%$24,760
    2002$8,430 +7.5%$24,760
    2001$7,838 +8.7%$24,760
    2000$7,211 $24,760

    Find assessor info on the county website

    Neighborhood: 11963

    Nearby schools

    GreatSchools rating
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    Estimated market value
    $10,268,400
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    Find out how much your home could sell for in as little as 3 minutes with a no-obligation cash offer.
    Estimated market value
    $10,268,400