.52 Acre Buildable Lot with Existing Cottage — North Mianus
Nestled at the end of a private road in the desirable North Mianus neighborhood, this .52-acre property offers a unique combination of privacy, potential, and flexibility. The lot is fully entitled with plans to build a 4,200 sq. ft. custom home, making it ideal for builders, investors, or end-users looking to create their dream residence.
In addition to the new-construction opportunity, the property includes an existing 1-bedroom, 1-bathroom cottage that is grandfathered in—perfect for rental income, a guest house, or an in-law suite while the main home is being built.
This is a rare offering in one of Greenwich's most sought-after areas, within the North Mianus Elementary and Eastern Middle School districts,
Lot/land
$1,575,000
9 Walnut St, Cos Cob, CT 06807
3beds
0.52Acres
Land
Built in 1970
0.52 Acres Lot
$-- Zestimate®
$1,063/sqft
$-- HOA
What's special
Private road
- 147 days |
- 747 |
- 19 |
Zillow last checked: 7 hours ago
Listing updated: February 20, 2026 at 11:42am
Listed by:
Peter Janis 203-249-1013,
BHHS New England Properties
Source: Greenwich MLS, Inc.,MLS#: 123887
Facts & features
Interior
Bedrooms & bathrooms
- Bedrooms: 3
- Bathrooms: 1
- Full bathrooms: 1
Heating
- Natural Gas, Hot Water
Cooling
- None
Interior area
- Total structure area: 1,482
- Total interior livable area: 1,482 sqft
Property
Lot
- Size: 0.52 Acres
- Features: Level
Details
- Additional structures: Guest House
- Parcel number: 082718/S
- Zoning: R-12
Utilities & green energy
- Water: Public
Community & HOA
Location
- Region: Cos Cob
Financial & listing details
- Price per square foot: $1,063/sqft
- Tax assessed value: $714,140
- Annual tax amount: $8,825
- Date on market: 10/27/2025
Estimated market value
Not available
Estimated sales range
Not available
$4,887/mo
Price history
Price history
| Date | Event | Price |
|---|---|---|
| 10/27/2025 | Listed for sale | $1,575,000+54.4%$1,063/sqft |
Source:  Greenwich MLS, Inc. #123887 Report a problem | ||
| 7/10/2025 | Sold | $1,020,000-11.3%$688/sqft |
Source:  Smart MLS #24073498 Report a problem | ||
| 3/6/2025 | Pending sale | $1,150,000$776/sqft |
Source: Smart MLS #24073498 Report a problem | ||
| 2/17/2025 | Contingent | $1,150,000$776/sqft |
Source:  Berkshire Hathaway HomeServices New England Properties #122061 Report a problem | ||
| 2/17/2025 | Pending sale | $1,150,000$776/sqft |
Source: Greenwich MLS, Inc. #122061 Report a problem | ||
| 2/12/2025 | Listed for sale | $1,150,000$776/sqft |
Source: Smart MLS #24073498 Report a problem | ||
Public tax history
Public tax history
| Year | Property taxes | Tax assessment |
|---|---|---|
| 2025 | $8,826 +3.5% | $714,140 |
| 2024 | $8,524 +2.6% | $714,140 |
| 2023 | $8,310 +0.9% | $714,140 |
| 2022 | $8,234 +6.6% | $714,140 +11.4% |
| 2021 | $7,722 +0.2% | $641,340 |
| 2020 | $7,709 -1% | $641,340 |
| 2019 | $7,786 +2.3% | $641,340 |
| 2018 | $7,613 -1.2% | $641,340 |
| 2017 | $7,708 +31.8% | $641,340 +30.8% |
| 2015 | $5,849 +2.6% | $490,490 |
| 2014 | $5,702 +2.8% | $490,490 |
| 2013 | $5,547 +2.8% | $490,490 |
| 2012 | $5,395 +3.4% | $490,490 |
| 2011 | $5,219 -13.3% | $490,490 -26.3% |
| 2010 | $6,020 +3.4% | $665,910 |
| 2009 | $5,820 +3.6% | $665,910 |
| 2008 | $5,620 +3.6% | $665,910 |
| 2007 | $5,427 +3.8% | $665,910 |
| 2006 | $5,227 -4.8% | $665,910 +46.6% |
| 2005 | $5,491 +8.7% | $454,160 |
| 2004 | $5,050 +3.4% | $454,160 |
| 2003 | $4,882 +35.2% | $454,160 +135.2% |
| 2001 | $3,610 +5.6% | $193,060 |
| 2000 | $3,417 -4.6% | $193,060 |
| 1999 | $3,581 | $193,060 |
Find assessor info on the county website
BuyAbility℠ payment
Estimated monthly payment
All calculations are estimates and provided by Zillow, Inc. for informational purposes only. Actual amounts may vary.
HOA fees may include property taxes on listings classified as Co-Ops. Contact the listing agent and/or owner for fee details.
Mortgage interest rates are dependent on a number of factors, including credit score, down payment, and repayment length. Interest rate data provided by Zillow Group Marketplace, Inc. as of 1/1/1970 from various mortgage lenders with which we have lead or other similar arrangements; the Estimated Payment is an average of those rates.
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Neighborhood: Cos Cob
Nearby schools
GreatSchools rating
- 9/10North Mianus SchoolGrades: K-5Distance: 0.8 mi
- 9/10Eastern Middle SchoolGrades: 6-8Distance: 2.4 mi
- 10/10Greenwich High SchoolGrades: 9-12Distance: 2.7 mi
Schools provided by the listing agent
- Elementary: North Mianus
- Middle: Eastern Middle
Source: Greenwich MLS, Inc.. This data may not be complete. We recommend contacting the local school district to confirm school assignments for this home.
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