Learn more about High-rise
High-rise buildings first became possible due to the invention of the elevator (also known as the lift in British English) and a cheap building material. The building itself is usually considered to be between 75ft to 491ft. Buildings larger than 492ft are considered to be classified as skyscrapers.
The materials used for the structural system of high-rise buildings are reinforced concrete and steel. Most American style skyscrapers have a steel frame, while residential tower blocks are usually constructed out of concrete.
Although the exact definition is immaterial, various bodies have tried to define what 'high-rise' means:
- The International Conference on Fire Safety in High-Rise Buildings defined a high-rise as "any structure where the height can have a serious impact on evacuation"
- The New Shorter Oxford English Dictionary defines a high-rise as "a building having many stories".
- Most building engineers, inspectors, architects and similar professions define a high-rise as a building that's at least 75 feet.
High-rise structures pose particular design challenges for structural and geotechnical engineers, particularly if situated in a seismically active region or if the underlying soils have geotechnical risk factors such as high compressibility or bay mud. They also pose serious challenges to firefighters during emergencies in high-rise structures. New and old building design, building systems like the building standpipe system, HVAC systems (Heating, Ventilation and Air conditioning), fire sprinkler system and other things like stairwell and elevator evacuations pose significant problems.
An example of challenges posed to firefighting crews in this real example. Fire companies were dispatched to a high-rise hotel in Lexington, Kentucky with reports of smoke in the building. When the fire companies investigated the source, they found smoke in the hallways, but not in the guest rooms. This in turn helped the fire companies determine that the problem was in the HVAC system and that a real hazard wasn't actually posed.