Coruscation

Mr. Walsdorf said that when Flank began selling condos at 385 West 12th Street, a building completed last year, buyers were interested in combining the smallish units, and "we hadn't really allowed for that possibility in the layouts." This time the firm decided to build large units and stuck to it, even after the financial collapse of 2008. (VillageCare, which operated the nursing home, agreed to sell the building in 2007 but was unable to move out until 2009.)

The conversion of public or institutional buildings into upper-class housing has a long history in New York. The former police headquarters at 240 Centre Street is a condo building, as are the former Y.M.C.A. on West 23rd Street and several former school buildings around the city. The onetime New York Lying-In Hospital, at 305 Second Avenue, is the Rutherford Place condos.

To housing advocates, those conversions represent a victory for the wealthy. Jerilyn Perine, the executive director of the Citizens Housing and Planning Council, an advocacy group, said it was important that the city adopt regulations "so that denser housing, particularly for singles, has a fighting chance in the market." She added, "It's great to have people with a lot of money living here -- we need their taxes and spending power -- but the loss of density is tragic, especially where mass transit access is so great."

But at least in the case of the Village Nursing Home, the rich will not be the only beneficiaries. A few years ago, residents there were crammed into outdated rooms that averaged less than 300 square feet per person (current regulations require at least 500). VillageCare was able to build a more modern facility, the VillageCare Rehabilitation and Nursing Center at 214 West Houston Street, using money from the sale of the Hudson Street building. A spokesman for VillageCare, Lou Ganim, said residents remaining in the Village Nursing Home at the time it was sold were transferred to the new facility.

Indeed, sometimes preservation advocates look to condo developers as white knights. Since the Bialystoker Center for Nursing and Rehabilitation on East Broadway closed last year, Laurie Tobias Cohen, the executive director of the Lower East Side Jewish Conservancy, has been "extremely eager" for a developer to buy the historic building and convert it to co-ops or condos. The closing of the nursing home was a great loss, she said; the goal now is to prevent the demolition, or further deterioration, of the building. "What we don't want," she said, "is to lose any more of the built historic fabric."