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
25
31 under contract
Median List Price
$3.70M
25 active listings
Median Closed Price
$2.90M
213 sales
Median Days on Market
47
25 active listings
Median $ / Sq Ft
$773
25 active listings
Sale-to-List Ratio
106.3%
213 sales
How this home compares
List Price
$6.99M
vs $3.70M median
88.8% above median
Price / Sq Ft
$771
vs $773 median
In line with median
Days on Market
0 days
vs 47 days median
47 days fresher than median
Based on 25 active and 213 closed sales (trailing 12 mo) of single family in Darien. Source: SmartMLS · As of November 8, 2026.
Location
451 Mansfield Avenue, Darien, Connecticut
Estimate Your Payment
Estimated Monthly Payment
Rates: Freddie Mac PMMS via FRED · Updated Nov 5, 2026per month
- Principal & Interest$37,855
- 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
- GuniteHeatedInfinity 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 #
- 24219917
- 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 11/8/2026. 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 11/8/2026 at 8:40 AM UTC.