How much does townhouse width affect sales?

At first glance, Manhattan’s toniest townhouses would seem to have little in common with mobile homes. But, in fact, both types of real estate share a metric for measuring value: the wider the better. Not only is townhouse width a point of pride for homeowners, buyers and brokers in New York City, it is one of the most important attributes appraisers use in determining the sale price of a townhouse, said Jonathan Miller, president of appraisal firm Miller Samuel. But how much does width actually impact the price per square foot of a property?

A review of 214 Manhattan townhouse sales that closed between July 2010 and March 2013 shows that wider townhouses don’t necessarily sell for a higher price per square foot. Indeed, the overall closing price of a home has more to do with location and layout than width, according to the data, compiled by StreetEasy. For example, a 13-foot, four-bedroom townhouse at 35 West 12th Street in Greenwich Village sold for $5.2 million back in 2011, while a nearby 20-foot, two-family townhouse at 69 Bedford Street fetched a mere $2.6 million that same year.

The average price for a townhouse was $5.3 million in 2012, according to the most recent Douglas Elliman townhouse market report, prepared by Miller.

“It really does become an issue of ego more than anything else,” said Jed Garfield, president of Leslie J. Garfield & Co., a brokerage that specializes in townhouse sales. “I’ve sold houses that are eight feet wide and 40 feet wide and there’s no appreciable difference between the widths.”

Instead, a better marker of value, the data sample shows, is how far a townhouse’s width deviates from the Manhattan average — 19.1 feet on the East Side and 19.7 feet on the West Side, according to the Elliman report.

For example, J. Christopher Flowers sold the 50-foot-wide Harkness Mansion at 4 East 75th Street to art mogul Larry Gagosian for $36.5 million in 2011, at a price of $1,682 per square foot. Last year, a 12.5-foot-wide townhouse at 153 East 78th Street sold for $6.1 million, or $2,083 per square foot — $401 more per square foot than Flowers’ former home. (Of course, Flowers famously paid $53 million for the Harkness Mansion in 2006.)

“As they get more wide they get rare,” said Chris Halstead, an executive vice president at Halstead Property, who is listing an 18-foot-wide townhouse at 333 East 82nd Street, which is priced at $2.5 million less than the 22-foot-wide house next door. “That [rarity] contributes to how attractive they are to buyers. As the homes get wider, there are fewer of them.”

That said, wider townhouses still carry a certain prestige. The wider the townhouse, the more flexibility a buyer perceives in the overall floor plan, said Miller.

But, he warned, excessive additions can decrease value. He remembers appraising a 15-foot-wide townhouse on the Upper East Side in which the owner had installed an elevator. The elevator took up nearly half the width of the floor plan and greatly decreased the value of the property, he said.

“It turns out that throwing amenities at a property and not considering a key attribute like width can detract from the value,” Miller said.

While flexibility in layout is dependent on width, a poorly designed use of space will decrease any value gained from extra width, he explained.

Townhouse specialist Paula Del Nunzio, a senior vice president at Brown Harris Stevens, said that her clients often request homes wider than 20 feet, but not for their layout potential. Instead, they are looking for legacy.

“The wider mansions were often created by extraordinary original architects,” explained Del Nunzio, naming icons like Stanford White, C.P.H. Gilbert and John Duncan.

The widest townhouses, she added, have a unique magnetism because they were crafted for “clients of the Gilded Age, who sought to reproduce an American version of the palaces of Europe.”

Del Nunzio is currently listing the 40-foot-wide townhouse of Broadway producer Hal Prince for $21 million and a 25-foot-wide historical Greenwich Street townhouse, built in 1819 and asking $19.5 million.

Just as buyers covet wide townhouses, there is also demand for the exclusivity of skinny townhouses. Manhattan’s slimmest townhouse, at 9.5 feet wide, is on the market for $3.5 million, or $3,530 per square foot. The 990-square-foot, four-story house at 75 1/2 Bedford Street includes a renovated basement, three bedrooms and two bathrooms.

“There is some cachet behind having the tiniest townhouse around,” said Sofia Song, head researcher at StreetEasy. “You can boast about that.”

The listing inventory for Manhattan townhouses has remained relatively stagnant during the past decade, decreasing slightly by 3.5 percent since 2003, from 426 listings to 411, Elliman’s report shows. Such scarcity in townhouse supply has major implications for how buyers perceive the value of unalterable attributes like width.

“The listing inventory is remarkably consistent because the housing stock isn’t changing,” Miller said. “You’re not seeing new development. You’re seeing rehab, but you’re not seeing new construction.”