25 Acres, 10,406 Square Feet, $2.8 Million: Inside the Sherborn Sale at 75 Washington Street

Sherborn does not announce itself. There is no commuter rail stop and not much of a downtown. So when a 10,406-square-foot house on 25.53 acres changes hands for $2.8 million, it is easy to miss that the price per foot is among the lowest we have seen for a home this large in our prestige towns.

75 Washington Street closed August 24, 2026 at $2,800,000. That is $269 per square foot of house, with the land thrown in at roughly $109,700 per acre if you divide the whole price by the whole parcel. For context, our last prestige-town profile, a Wellesley sale at 222 Grove Street, closed at $778 per square foot. Same state, same decade, same kind of buyer pool, and a price per foot almost three times higher.

Zillow's Zestimate for 75 Washington Street is $2,799,800. The house sold for $2,800,000. That is a $200 gap on a $2.8 million sale, which is about as close as an automated valuation ever gets. The tax-assessed value on record is $2,522,100, so the buyer paid 1.11x the assessment, a modest premium compared with the 2x to 3x gaps we have flagged in other towns.

Two honest readings of that agreement. Either the market and the model both found the same number for a very unusual property, or the model leaned on the same sold comps the buyer's agent did. We cannot tell which from public data, but either way this does not look like a mispriced outlier. It looks like a price Sherborn's large-lot market was prepared to pay.

Line the five up and a pattern jumps out: price per square foot falls as the house gets bigger. The two homes over 7,500 square feet, 75 Washington and 4 Green Lane, sold at $269 and $216 per foot. The three mid-size houses, between roughly 3,200 and 5,300 square feet, sold between $334 and $465 per foot. The smallest of them, 7 Goulding Street East, cost 1.7x as much per foot as 75 Washington.

That is the classic large-house discount, and Sherborn has an extra layer: the buyer pool for 10,000-plus square feet on a 25-acre carry is thin. Sellers of big houses here are pricing against a small pool of buyers, not against the town median.

The sale that actually undercuts 75 Washington on a per-foot basis closed nine days later. 4 Green Lane (5 bedrooms, 6 baths, 7,592 square feet, 2.06 acres) sold September 2 for $1,640,000, or $216 per square foot. Its assessed value is $2,250,100, so it sold at roughly 73% of assessment, and Zillow's Zestimate of $1,955,100 sat about 19% above the closing price. We would be careful about reading that as a distressed sale. Public sold data does not show the reason, and an assessment can lag or lead a house for many reasons. But as a data point for what big-house buyers in Sherborn will and will not pay, it is the sharpest in the set.

Public sold data tells us the parcel is 25.53 acres. It does not tell us how much of that is buildable, wet, protected or enrolled in a current-use program, and each of those changes what the land is worth to a buyer. A parcel this large can carry conservation, agricultural or wetland constraints that cap what can be done with it. Anyone eyeing a property like this should pull the deed, the Conservation Commission file and the assessor's land classification before running any math on a per-acre number.

Still, even if only a fraction of the land is usable, the arithmetic is striking. At $2.8 million all in, the buyer paid less than the $3.0 million that a 7,111-square-foot house on 0.93 acres fetched in Lexington last month.

Three things. First, Sherborn's top end is real: a $2.8 million closing is nearly double the town's recent median. Second, the market is pricing size and land separately, which is why square-foot comparisons across Sherborn are close to useless unless you adjust for lot. Third, the $200 Zestimate miss suggests the model has plenty of comparable large-lot data here, which is not a given in a town with so few single-family closings.

For buyers, the practical read is that Sherborn rewards the person willing to carry a big house and a lot of land. For sellers of large homes, it is a reminder that the buyer pool is selective and that the price per foot you see in Wellesley or Weston does not translate.