Avenue, with a side entrance on 56th Street only for residents. On the sidewalk opposite the main entrance, there is a four-sided brown-and-beige clock, which was created by the Electric Time Company and is nearly tall. Retail outlets include Gucci's flagship store at ground floor retail. Architecture The 58-story Trump Tower was designed by Der Scutt for developer Donald Trump. It is high, making it the 64th tallest building in New York City. The top story is marked as "68" because, according to Trump, the five-story-tall public atrium occupied the height of ten ordinary stories. However, several Bloomberg L.P. writers later determined that Trump's calculations did not account for the fact the ceiling heights in Trump Tower were much taller than in comparable buildings, and the tower did not have any floors numbered 6–13. According to one author, the building may have as few as 48 usable stories. , the building's official owner is GMAC Commercial Mortgage, according to the New York City Department of City Planning. Form and facade The 28-sided massing was intended to give the tower more window exposure. The large number of sides arises from Trump Tower's horizontal setbacks; this contrasts with other buildings, which typically have vertical setbacks. The exception is at the base, where the southwest corner has several stepped setbacks. The Trump Organization constructed terraces on the building's setbacks in exchange for extra floor area. These were included as part of Trump's agreement with the city during construction. There is a terrace on the fifth floor on the northern (57th Street) side of the building, with a smaller fourth-floor terrace on the southern (56th Street) side. The fifth-floor north-side terrace had several trees and a fountain, while the fourth-floor south-side terrace has little more than a few granite benches. Above the main entrance is a logo with brass capital letters in Stymie Extra Bold font, which reads "Trump Tower". A concrete hat-truss at the top of the building, similar to one used in the Trump World Tower, ties exterior columns with the concrete core. This hat-truss increases the effective dimensions of the core to that of the building allowing the building to resist the overturning of lateral forces such as those caused by wind, minor earthquakes, and other impacts perpendicular to the building's height. Structural features The tower is a reinforced concrete shear wall core structure. At the time of its completion, it