In case you haven’t seen the renderings for 15 Union Square West, here they are. And here’s one $4,100,000 listing. The interesting thing about this development is that it retains the original cast-iron window frames from the 19th-century while wrapping the whole thing in 21st-century glass. Take a close look when you walk by. And here’s the history of the building. And a recent New York Times peek inside the model apartment.