Diamond National Building (New York City, New York)

 office building, commercial building, International style architecture

266-foot, 24-story International-style office building completed in 1961. Designed by Emery Roth & Sons, it is clad in a curtain wall of black-tinted glass, dark-grey metal spandrels, and thin, silver metal mullions. Also known as the Rodale Building, its main entrance is at the south end of the west facade on the avenue, with two sets of revolving glass doors and another set of traditional glass doors to the left. The ground floor has a frame of black polished granite, and glass-and-metal storefronts along the rest of the west facade, and west end of the north facade on 46th Street. Further east there is a section of vertical metal louvers (with a metal service door in the middle) topped by a white marble band. The east end has a wide restaurant storefront topped by a long, rounded, brown canvas awning.

The building has two main masses: the 24-story main tower at the west end, and the longer, but narrower and shorter 16-story section at the east. The east section's north facade sets back above the 6th floor, with a very shallow setback above the 11th floor, and a somewhat shallower setback above the 13th floor. The east and south facades rise straight up from the ground. The west section is roughly L-shaped, with a single setback above the 11th floor on both the west and north facades, and a small wing extending onto the roof of the east section, at the south side, creating the L-shape. The lower setbacks at both the east and west sections has green roofs, as does much of the main roof of the lower, east section. The ground floor along the avenue is occupied by Fidelity Investments, and the restaurant storefront at the east is occupied by Sparks Steakhouse.