LLNYC’s Look at Listings: Carlton House’s most expensive listing

21 East 61st Street 15A

From LLNYC’s Look at Listings: Thanks to a wealth of differing definitions, we’re still not entirely sure what constitutes a cond-op, but this 4,649-square-foot Carlton House pad apparently is one, according to StreetEasy.

The spread, which is now seeking $21.5 million, has been on and off the market since 2013, with its asking price starting at $21 million. It’s the most expensive unit at the building right now but its upstairs neighbor is also up for grabs, but at a slightly cheaper $19.9 million — perfect for anyone who dreams of duplexes. [more]