Folk singer Art Garfunkel’s swanky Upper East Side penthouse, just off Central Park, caught fire Thursday morning, sources said.

The blaze began in the insulation inside the 15th-floor home on East 79th Street and firefighters were called for a smoke condition around 11:40 a.m., sources said.

The singer was not home at the time, building sources said.

It took two hours for firefighters to get the blaze, which appeared to be caused by a frozen pipe, under control, officials said.

The singer returned briefly to assess the damage, they added.

The damage was “extensive,” according to one source, who added: “There was a lot of water.”

No one was injured, according to the FDNY.

Apartments in the 15-story building go for tens of millions of dollars.