Flatiron Building. The Flatiron Building, originally the Fuller Building, is a triangular 22-story, 285-foot-tall steel-framed landmarked building at 175 Fifth Avenue in the eponymous Flatiron District neighborhood of the borough of Manhattan in New York City. Designed by Daniel Burnham and Frederick P. Dinkelberg, and known in its early days as Burnham's Folly, it was completed in 1902 and originally included 20 floors. The building sits on a triangular block formed by Fifth Avenue, Broadway, and East 22nd Street, where the building's 87-foot back end is located, with East 23rd Street grazing the triangle's northern peak. The name Flatiron derives from its triangular shape, which recalls that of a cast-iron clothes iron. The Flatiron Building was developed as the headquarters of construction firm Fuller Company, which acquired the site from the Newhouse family in May 1901. Construction proceeded at a very rapid pace, and the building opened on October 1, 1902. A cowcatcher retail space and a one-story penthouse were added shortly after the building's opening. The Fuller Company sold the building in 1925 to an investment syndicate. The Equitable Life Assurance Society took over the building after a foreclosure auction in 1933 and sold it to another syndicate in 1945. Helmsley-Spear managed the building for much of the late 20th century, renovating it several times. The Newmark Group started managing the building in 1997. Ownership was divided among several companies, which started renovating the building again in 2019. Jacob Garlick agreed to acquire the Flatiron Building at an auction in early 2023, but failed to pay the required deposit, and three of the four existing ownership groups took over the building. In October 2023, it was announced that the building would be converted to residential condominiums. The Flatiron Building's facade is divided vertically into three sections, similarly to the components of a classical column. The three-story base is clad with limestone, while the upper stories are clad with glazed terracotta. The building's steel frame, designed by structural engineering firm Purdy and Henderson, was intended to withstand four times the maximum wind force of the area. Called one of the world's most iconic skyscrapers and a quintessential symbol of New York City, the building anchors the south end of Madison Square and the north end of the Ladies' Mile Historic District. The neighborhood around it is called the Flatiron District after its signature, iconic building. The building was designated a New York City landmark in 1966, was added to the National Register of Historic Places in 1979, and was designated a National Historic Landmark in 1989. A survey in 2023 found that the Flatiron Building was the fourth-most-loved building in the United States. The Flatiron Building sits on a triangular block formed by Fifth Avenue to the west, Broadway to the east, and East 22nd Street to the south. The western and eastern facades converge, forming a peak at its northern corner where Fifth Avenue and Broadway intersect with East 23rd Street. The shape of the site arises from Broadway's diagonal alignment relative to the Manhattan street grid. The site measures 197.5 feet on Fifth Avenue, 214.5 feet on Broadway, and 86 feet on 22nd Street. Above the ground level, all three corners of the triangle are rounded. Adjacent buildings include the Toy Center to the north, the Sohmer Piano Building to the southwest, the Scribner Building to the south, and Madison Green to the southeast. The Flatiron Building is at the northern end of the Ladies' Mile Historic District, which extends between 15th Street to the south and 24th Street to the north. By the 1990s, the blocks south of the building had also become known as the Flatiron District. The St. Germain Hotel was built by 1855 on the south end of the lot. It was one of several hotels built in the neighborhood during the mid-19th century. Amos Eno purchased the entire block in 1857 for $32,000, and he shortly built the Fifth Avenue Hotel on a site diagonally across from it. At some point after 1880, Eno tore down the St. Germain Hotel and replaced it with a seven-story apartment building, the Cumberland. On the remainder of the lot, he built four three-story buildings for commercial use.