Building Wrapped in Gauze

I thought this was really unusual, seeing these two buildings across from the Metropolitan Museum of Art, that appear to be wrapped in some kind of gauze.  I guess I should have crossed the street to see how close I could get to the buildings to see what the material is.  Actually the buildings are not wrapped, but there is scaffolding that extends from the street up to the roof, and the scaffolding is what is wrapped.  They are obviously doing something to the exterior of the building and I am thinking that the material will protect anyone below if someone drops a tool.  They might be looking for cracks or voids in the masonry which they then have to repair, so might be pieces of loose mortar that might fall.  Anyhow it is such an interesting thing, to see such a drastic change in appearance of a normal looking building.