When Manhattan design and development firm Flank began converting a former nursing home in the West Village from a warren of 200 tiny rooms into a condo building with all of 10 units two years ago, few believed the project could succeed. "Nobody thought there was a market in the Village for units at these sizes and these prices," Tim Crowley, a Flank managing partner, said. How times have changed. Since bringing the property at 320 West 12th St. to market in June, every single unit has now been sold—at prices ranging from $8.75 million to $31 million. Closings began this week. With only two units to a floor and none smaller than 3,200 square feet, Mr. Crowley refers to these as "townhouses in the sky," but with all the amenities of a full-service building. "This is not your average cookie-cutter luxury condo," Mr. Crowley said during a building tour Monday. Far from it: The bottom two floors are divided into duplexes known as the east and west mansions, with two units on each of the floors above, and at the very top two duplex penthouses. The west mansion was the largest and most expensive space in the building, spanning 9,600 square feet on three floors (it includes basement space, as well). It carried an asking price of $25 million. The penthouse facing the Hudson River cost $21.5 million, while the other was turned into a triplex by the buyer, who combined the $19.5 million penthouse with a $10.5 million unit below, creating an 8,550-square-foot pad. The simplexes cost between $8.75 million and $10.75 million. What truly sets the project apart is its design. Flank, which serves as the architect and broker for all of its developments, took the former, Georgian-style Laura Spelman Hall, built in 1905, and gutted it. The team then studied classic Park Avenue apartments and how the classic buildings broke up the apartments into more formal spaces. But rather than walling each room off, they are connected with generous passages. Nowhere are the wide-open great rooms in vogue. "It's our take on uptown downtown, a really classic yet modern space," Mr. Crowley said. Each apartment features such high-end details as four-inch oak floors and bathrooms lined with statuary marble. Leonard Steinberg, a Douglas Elliman broker who showed units in the Abingdon, said the project was perfectly fit. "There's a group of people with tremendous wealth who can afford anywhere in Manhattan and they're choosing the Village," he said. "The Abingdon really celebrates its location and its history, and I think that's the kind of charm people are looking for here." Mr. Crowley admits that the project's success was in part due to a lucky piece of timing. Construction delays at its new facility kept the Village Cares Nursing Home from moving out as planned in 2009. "Had we closed then, we probably would have had to sell, because no one was getting construction financing at that point," he said. "And had we finished the project (in 2010), we'd only have gotten $1,400 a foot, rather than $3,000 a foot." "It's amazing," Mr. Crowley said, "how fast the market has changed." As for the changes in the Village, that this project once housed 200 women and will now only cater to 10 families—a fact that has drawn some scorn for the Abingdon in the press and the community—Mr. Crowley said that is simply the way of New York in the 21st Century. "I can't afford to live here either," he said. "In this business, you can either be a dealer or a user, you can't be both. That's the market."