For those houses, the issue is more supply than demand. The number of luxury homes listed for sale in the first quarter more than doubled from a year earlier, while buyer interest in those properties has remained about the same, said Miller, a Bloomberg View contributor. His firm defines luxury as the top 10 percent of the market by price.

Supply Glut

At the current pace of sales, it would take 4.9 years to absorb Greenwich’s inventory of 252 luxury houses on the market at the end of the first quarter, according to Miller Samuel and Douglas Elliman. That compared with 9.9 months for the 102 condos listed, the shortest of any property type.

“The tide is changing,” said Tenney, who lowered the asking price of her earlier home before finding a buyer. “Nobody wants those huge houses anymore. You look back and there’s rooms you never even entered.”

While not stand-alone houses, Greenwich’s new condos are still high-end properties that keep with the town’s reputation for prosperity. The Tenneys’ three-bedroom unit, listed for $3.5 million, spans two floors and includes an office, a two-car garage and a patio overlooking a patch of lawn that will be maintained by the condo association, Katherine Tenney said.

The condo is one of seven planned at the Harbor development, off of Steamboat Road and within half a mile of Greenwich’s downtown retail strip and the Metro-North train to Manhattan. Buyers at the Harbor can receive amenities such as room service, car service and dry cleaning from the Delamar Greenwich Harbor hotel across the street, said Michele Tesei, a broker with Houlihan Lawrence.

“The developers saw a niche for people who wanted to downsize, but not necessarily the size of the house,” Tesei said during a tour of the property. “You’re still getting your square footage, you’re still getting your space, but you’re not maintaining your lawn and you’re not maintaining a pool.”

Empty Nesters

The project is rising on the site of a former parking lot owned by developer Fareri Associates, which, after briefly considering rentals, decided that homeowners who finally sell their large properties would be looking for a new type of place to live, said Jim Carnicelli, president of Gateway Development Group, the project’s construction manager.

“We went through a bunch of iterations,” said Carnicelli. “We knew there would be an empty-nester market. It was a matter of waiting for the right time for it to come to fruition.”