One building resident said that no work was actually done during this time. The Department of Buildings had issued several permits in recent years, including for "removal/replacement of defective brickwork, limestone and terra cotta segments."
The two restaurants in the retails spaces have also moved on, most recently Jiang Diner after six whole weeks ... and, in the corner space, Madame Vo BBQ, which seems to have permanently merged with its sister restaurant on 10th Street.
Anyway, nice to see the building again. (And bring back Bamboo House!)
As for sidewalk bridges, I'd say the one outside 19-23 St. Mark's Place has the current record with more than five years maybe? (In emeritus status: the sidewalk bridge around the long-empty P.S. 64 on Ninth and 10th streets.)