Tall building design entails a conceptual design, an approximate analysis, a preliminary design, and optimization to safely bear gravity and lateral stresses. Strength, serviceability, stability, and human comfort are the design objectives. The structural engineer is responsible for developing strong yet economical structures that fulfill these requirements.
The first step in designing a tall building is to determine what kind of structure will be needed. There are four basic types of construction: frame, shell, column, and interior support system. A frame building has vertical members called "studs" that hold up the roof. The studs may be made of wood or steel. A shell building has a rigid outer wall that contains the weight of the building and any contents it might have. This type of building can be made of concrete or brick. A column-supported building has its vertical support beams called "columns" which contain the weight of the building. The columns may be made of steel or timber. An interior-supported building has internal columns that connect the floors and walls together. These columns may be made of steel or wood.
Next, the height and other characteristics of the building must be determined. How high would you like the building to be? What kind of roof does it need? What size windows?
A skyscraper is a high-rise building with more than 40 storeys and a height of more than 150 meters. Buildings with 10 to 20 stories were the first to be called "buildings." Construction technologies altered the concept during the twentieth century. The modern skyscraper is a relatively new architectural style that emerged in the United States around 1880. It was developed through trial and error by architects who were looking for ways to make large buildings more efficient structurally.
The number of floors or storeys is the vertical distance between the ground floor and the roof, excluding any outdoor space such as a balcony or patio. A floor can have any number of rooms, but most often includes one or more bedrooms. A floor may also include a kitchen, a dining room, a living room, a study, or a laundry room. Floors are usually made of concrete, wood, or steel. The weight of buildings is mainly carried by their roofs. The strength of a roof is determined by its design and material quality. A well-designed roof will distribute the weight of a building over a large area which reduces the load on each joist or beam.
A skyscraper is a very tall building. The term is used to describe a building with more than five floors above ground level. There are no official guidelines regarding how high a building should be to be considered a skyscraper.
Steel is used to build twentieth-century skyscrapers, and architects continue to try to outdo the last great effort by creating higher and taller buildings that can withstand wind and adjust to changing temperatures. You must be a Study.com member to access this lesson. Sign up for a free Study.com account today.
It takes a lot of steel to build a skyscraper. A single floor area of a 20-story building is about 7,500 square feet (700 m2). To make a building that size you need about 21,000 square feet (1,900 m2) of floor space. For comparison, the Empire State Building has a floor area of about 100,000 square feet (9,300 m2).
Skyscrapers are made out of steel because it's strong and light, which is what builders want in a roof material. Steel frames are covered in panels of glass or concrete. The walls resist lateral force due to wind pressure. Bracing is needed inside high-rise buildings to keep them from collapsing under their own weight.
Some modern skyscrapers are made out of reinforced concrete instead. These buildings use thick layers of cement and gravel mixed with water and sand to form a hard stone that can be carved into any shape.
Because inhabited area cannot be too far away from outside glass, the footprints of the structures are constrained, limiting their height. In certain cases, the constraints are structural. Because of the soil characteristics, high-rise buildings are excessively expensive or impossible to erect over a particular height. Even if the buildings were possible, there would be no point because people wouldn't be able to reach the upper floors.
In other cases, the constraint is due to government regulations on maximum building heights. These restrictions are put in place to prevent urban sprawl and ensure that cities do not exceed their boundaries in terms of land use development. For example, in New York City, which has no natural barrier between its five boroughs, it is prohibited by law for any building to exceed 40 feet (12.19 m) in height if it is within 100 feet (30.5 m) of another building of equal or greater height. There must also be at least one floor below street level for such a building.
Cities tend to have a large number of low-to-mid-range buildings, with few high-rises. This is because high buildings require a lot of space per square foot, which means they cost a lot of money. Also, the construction of high buildings requires special skills and technology that most cities don't have access to. Finally, high buildings are at risk of being destroyed by earthquakes or hurricanes.
Long beams of solid iron meant that a lightweight material could support greater weight, allowing for the construction of a higher building. A steel skeleton construction is used to build skyscrapers. Vertical columns are joined to horizontal girder beams on each floor to assist strengthen and reinforce the structure. The taller the building, the more pressure it can sustain before it needs to be reinforced with metal rods.
Tall buildings provide more space per square foot, but they also use up much of the available land area. Land prices increase as height increases, so builders need to make sure that they don't build too high. The tallest building in North America is the Willis Tower (formerly known as "The Sears Tower") in Chicago. It is 1,453 feet (442 m) tall with 51 floors.
Buildings over 100 meters (330 ft) high are rare because they require huge amounts of expensive structural steel and take years to construct. Only two such buildings have been completed in history: the Petronas Towers in Kuala Lumpur, Malaysia (981 m or 3281 ft) and The World Trade Center in New York City (1,471 m or 4894 ft).
It's difficult/impossible to build a house that is higher than its neighborhood, so most homes are between 15 and 30 stories high. Some cities limit how high you can build if they have not done so already.