While you're up around the Dalton School, 108 East 89th, check out the
south (garden) facade of the Cooper-Hewitt Museum, 1902, formerly the
Andrew Carnegie mansion, 2 East 91st.  I once proposed a trellis-like
structure for the heavy vines to climb on, so that one could machette the
gap between the trellis and the brick-and-limestone facade.  Love of leaf
overcame preservation logic, and the masonry has not received the full
attention and treatment that it might have...repointing, bio-cleaning,
tendril control, sun and air drying.  Those vines have been there for
decades.  Could the shading effect actually be beneficial in moderating the
temperature swings?

Except for that rooftop limestone urn being upended by a wisteria vine
under its corner, I can't say the building was suffering in a major way but
I havn't looked in recent years.  And the color the foliage reflects on the
interior is "charming".  Other opinions?

--Jim