451 Mansfield Avenue
Darien, Connecticut 06820
- Beds
- 7
- Baths
- 9 | 2
- SqFt
- 9,058
- Acres
- 2.70
- Year Built
- 1999
- Property Type
- Single Family

Matt Caiola
Luxury Real Estate Advisor
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About This Home
Set back from the road on 2.7 beautifully landscaped acres, 451 Mansfield Avenue offers the privacy, grandeur, and distinctive character of a true country estate. A sweeping circular drive introduces a grand residence distinguished by its striking stone facade and timeless architectural detailing, a substantial two-story guest house, and a magnificent outdoor setting centered around a 24' x 48' infinity-edge pool. Extensive custom stonework, elegant terraces, and lush grounds enhance the property's distinctive estate-like character. Extensively renovated in 2026, the residence features all- new mechanical systems, new windows, and thoughtfully redesigned interiors. Blending timeless architectural elegance with sophisticated contemporary luxury, the home offers approximately 9,000 square feet of finished living space, including a light-filled 1,600-square-foot walk-out lower level. Inside, a graceful, curved staircase rises from the herringbone-floored foyer, introducing beautifully proportioned rooms, distinctive millwork, and refined architectural detailing. Formal living and dining rooms, each with a custom marble fireplace, provide gracious entertaining spaces, while a richly paneled library with coffered ceiling and fireplace offers a distinguished private study.
Key Facts
- City/Town
- Darien
- Neighborhood
- N/A
- Property / Style
- Single Family · Colonial
- Year Built
- 1999
- Days on Market
- 0 days
- Beds
- 7
- Baths
- 9 full · 2 half
- Living Area
- 9,058 sq ft
- Lot Size
- 2.70 acres
- Garage / Parking
- 4 garage
- Property Taxes
- $47,118 / Annually
Market Snapshot
The Darien Market
Single Family · trailing 12 months
Active Listings
30
23 under contract
Median List Price
$3.92M
30 active listings
Median Closed Price
$2.87M
216 sales
Median Days on Market
30
30 active listings
Median $ / Sq Ft
$771
30 active listings
Sale-to-List Ratio
106.3%
216 sales
How this home compares
List Price
$6.99M
vs $3.92M median
78.1% above median
Price / Sq Ft
$771
vs $771 median
In line with median
Days on Market
0 days
vs 30 days median
30 days fresher than median
Based on 30 active and 216 closed sales (trailing 12 mo) of single family in Darien. Source: SmartMLS · As of October 13, 2026.
Location
451 Mansfield Avenue, Darien, Connecticut
Estimate Your Payment
Estimated Monthly Payment
Rates: Freddie Mac PMMS via FRED · Updated Oct 8, 2026per month
- Principal & Interest$38,690
- Property Taxes$3,927
- Insurance$2,328
- HOA$0
Estimates only. Actual rates, taxes, insurance, and HOA fees vary. Consult a lender for current rates.
Location
- City/Town
- Darien
- Neighborhood
- N/A
- County
- Fairfield
Residence
- Property Type
- Single Family
- Style
- Colonial
- Year Built
- 1999
- New Construction
- No/Resale
- Living Area
- 9,058 sq ft
- Below Grade
- 1,586 sq ft
Schools
- Elementary
- Per Board of Ed
- High
- Per Board of Ed
Interior
- Heating
- Hot Air
- Heat Fuel
- Propane
- Cooling
- Central Air
- Fireplaces
- 6
- Laundry
- Upper Level
- Appliances
- Gas RangeWall OvenMicrowaveRange HoodSubzeroDishwasherWasherElectric DryerWine Chiller
- Basement
- FullHeatedSump PumpStorageGarage AccessCooledPartially Finished
- In-Law Apartment
- PossibleDetachedSeparate Entry
- Interior Features
- Sauna
Exterior & Lot
- Lot Size
- 2.70 acres
- Zoning
- R2
- Garage / Parking
- 4 garage spacesAttached Garage
- Waterfront Details
- Not Applicable
- Water Source
- Public Water Connected
- Sewer
- Public Sewer Connected
- Pool
- GuniteHeatedPool HouseInfinity EdgeSalt WaterIn Ground Pool
- Construction
- StoneWood
- Roof
- Slate
- Foundation
- Concrete
- Lot Description
- Lightly WoodedDryProfessionally Landscaped
Listing & Financials
- Property Taxes
- $47,118 / Annually
- Days on Market
- 0
- MLS #
- 24213571
- MLS Status
- Active
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This information is believed to be accurate, but without warranty.
The IDX display contains information sourced from SmartMLS, Inc. as of 10/13/2026. This information is provided for consumers' personal, non-commercial use and may not be used for any purpose other than to identify prospective properties consumers may be interested in purchasing or leasing. Data is deemed reliable but is not guaranteed accurate by the MLS, the listing broker, the listing agent, or Matt Caiola. Buyers and tenants should independently verify all information that matters to their decision.
Map locations may be approximate. Any offer of compensation, if applicable, is made only to participants of the MLS where the listing is filed. ©2026 Smart MLS, Inc. All rights reserved.
Data last updated on 10/13/2026 at 11:55 AM UTC.