The idea behind 20 East End Avenue, the Corigin-developed, Robert A.M. Stern-designed condo building rising next to the East River, is to provide residents (who will be paying $4.5 million and up) with the same type of experience that one would get from owning a classic Emery Roth or Rosario Candela co-op. Since an entirely faithful homage to those types of buildings would have necessitated truly enormous 7,000- and 8,000-square-foot apartments, though, in order to maximize the number of units while maintaining the same sense of luxury and decadence, Corigin and Stern went all out with the shared amenity spaces, which they view as extensions of the apartments themselves. (This is your gym, your wine cellar, poker room, etc.—you just happen to share it with your seventy or so other superrich roommates.) The amenities are, to be fair, pretty amazing (including a motor court with the city's first newly constructed porte-cochère since the 1930s). The apartments, with every detail custom designed by Stern, are nothing to sneeze at either. The building's sales office includes a partially built out model of a four-bedroom unit (minus two of the bedrooms), which we recently got a tour of and now bring to you.