The US applies several zoning categories, such as residence, commercial, manufacturing or special purpose district. Every zoning district has different kinds of regulations and restrictions on building’s bulk, setbacks, parking, open space, FAR and height regulations.
Even though the US was the birthplace of highest buildings, with most of the skyscrapers located in NYC and Chicago, America does not build higher anymore. The main reason are the height restrictions made by the FAA (Federal Aviation Administration). According to the FAA, buildings in the US cannot be higher than 2000 feet, with a limit of 1000 feet buildings near airports. (The Tower Info, 2019)
New York City shows how the height regulations vary per district and zoning district. R5 (residence district category 5) districts of Brooklyn contains mostly low-rise buildings with high density, up to three or four-story high constructions destined for multiple-family buildings. On the other hand, the C5 (commercial district) with a high FAR permits the construction of high towers and mixed use buildings. In these areas are some of the most popular shopping streets, like Fifth Avenue, Madison Avenue, and East 57th.
The height of buildings are controlled by the sky exposure plane, height restrictions and tower rules. A sky exposure plane is applied for non-contextual (height factor) buildings, and it is a virtual sloping plane which the building should not penetrate. Various zoning districts and streets require different angles of sky exposure plane. For instance, wide streets require a steep slope while the narrow streets require a gradual slope.
However, there can be different tower regulations in high-density areas such as the R9 or R10 district. In these districts, under special circumstances the height of a building can be taller than the sky exposure plane, if they obey setback and lot requirements. (Kulichik, 2018)
Several cities in the US like Madison (Wisconsin), San-Jose (California) and Washington DC have local height restrictions. For example, in Madison, construction of a higher building within one mile of Wisconsin State Capitol is not allowed. San-Jose does not allow construction constructions higher than 300 ft. within the city center, since it is located close to the city’s international airport. And in Washington, the maximum height on residential streets is 90 feet, on commercial streets 130 feet and on Pennsylvania Avenue, it is 160 feet.
