“It’s delicious irony that the architects who needlessly pressed their personalities onto the ‘re-creation’ of the building to house the Barnes Foundation collection now protest the decision to demolish their museum,” said Jay Raymond, a former teacher at the Barnes and a litigant against the move.

Many architects say they were shocked by Diller Scofidio’s demolition proposal, given the firm’s reputation for creative interventions with historic properties like Lincoln Center.

“All of us who knew them thought this was going to be pretty much a slam dunk — that they would save the Folk Art Museum,” said Peter Wheelwright, a former chairman of the architecture program at Parsons, the New School for Design. “I knew they were capable of doing it and that, because of their friendship, that they would make a sincere, genuine, wholehearted effort.”

MoMA acquired the Folk Art building in 2011 after that institution defaulted on its construction debt. The building, just 10 years old at the time, had won its share of design awards. Last spring, MoMA announced a plan to raze it, arguing that the existing design was unsuitable as a connection between MoMA’s original building and galleries in a Jean Nouvel-designed tower planned for the other side of the Folk Art building. Many objected and MoMA then hired Diller Scofidio to re-examine the situation.

“I never thought it would be easy,” Ms. Diller said in an interview. “We stepped into harm’s way with the expectation that we would figure out a way of saving the day.”

But after six months of study, the firm came to the same conclusion as MoMA.

Any effort to reconfigure the existing building, Diller Scofidio determined, would require changing it beyond recognition and to preserve the facade alone would be an empty gesture. “In the end, we realized that the degree of disfigurement to the building would be of no good to the architects,” Ms. Diller said, “and the level of compromise to the program would be of no good to MoMA.”