Tower block

A tower block, high-rise, apartment tower, residential tower, apartment block, block of flats, or office tower is a tall <a href="/facts/Building/edSjKXje">building</a>, as opposed to a <a href="/facts/Low-rise_building/peWrXPlb">low-rise building</a> and is defined differently in terms of height depending on the <a href="/facts/Jurisdiction/0Kb8hao4">jurisdiction</a>. It is used as a <a href="/facts/Apartment_building/AnqWV09E">residential</a> or <a href="/facts/Office_building/uUPmgVFb">office building</a>, or has other functions, including <a href="/facts/Hotel/7B30LqSv">hotel</a>, <a href="/facts/Retail/unzV9sPF">retail</a>, or with multiple purposes combined. Residential high-rise buildings are also known in some varieties of English, such as <a href="/facts/British_English/ymJR5Rnd">British English</a>, as tower blocks and may be referred to as MDUs, standing for multi-dwelling units. A very tall high-rise building is referred to as a <a href="/facts/Skyscraper/5nM0naVB">skyscraper</a>.
High-rise buildings became possible to construct with the invention of the <a href="/facts/Elevator/ug3nh0o8">elevator</a> (lift) and with less expensive, more abundant building materials. The materials used for the <a href="/facts/Structural_system/4tyfPn2J">structural system</a> of high-rise buildings are <a href="/facts/Reinforced_concrete/aUTUKAQF">reinforced concrete</a> and <a href="/facts/Steel/aN6qWo4H">steel</a>. Most <a href="/facts/North_American/djNjCQIl">North American</a>–style <a href="/facts/Skyscraper/5nM0naVB">skyscrapers</a> have a <a href="/facts/Steel_frame/jNHlGJtx">steel frame</a>, while residential blocks are usually constructed of concrete. There is no clear difference between a tower block and a skyscraper, although a building with forty or more stories and taller than 150 metres (490 ft) is generally considered a skyscraper.
High-rise structures pose particular design challenges for <a href="/facts/Structural_engineering/Wj1vpoGh">structural</a> and <a href="/facts/Geotechnical_engineering/Nw55uq9R">geotechnical</a> engineers, particularly if situated in a <a href="/facts/Seismic_activity/NGjIzagw">seismically active</a> region or if the underlying soils have geotechnical risk factors such as high <a href="/facts/Compressibility/eePznleN">compressibility</a> or <a href="/facts/Bay_mud/h9Rot16n">bay mud</a>. They also pose serious challenges to firefighters during emergencies in high-rise structures. New and old building design, building systems such as the building <a href="/facts/Standpipe_(firefighting)/SrGUC4aX">standpipe</a> system, <a href="/facts/HVAC/gm1UQdR6">HVAC</a> systems (heating, ventilation and air conditioning), <a href="/facts/Fire_sprinkler/hR8tLFXH">fire sprinkler</a> systems, and other things such as stairwell and <a href="/facts/Elevator/ug3nh0o8">elevator</a> evacuations pose significant problems. Studies are often required to ensure that pedestrian <a href="/facts/Wind_engineering/SjSwQvY1">wind comfort</a> and wind danger concerns are addressed. In order to allow less wind exposure, to transmit more daylight to the ground and to appear more slender, many high-rises have a design with <a href="/facts/Setback_(architecture)/fvpqwm5S">setbacks</a>.
<a href="/facts/Apartment_building/AnqWV09E">Apartment buildings</a> have technical and economic advantages in areas of high <a href="/facts/Population_density/70zGTCFc">population density</a>, and have become a distinctive feature of housing accommodation in virtually all densely populated <a href="/facts/Urban_area/fu9v8h5P">urban areas</a> around the world. In contrast with <a href="/facts/Low-rise/peWrXPlb">low-rise</a> and single-family houses, apartment blocks accommodate more inhabitants per unit of area of land and decrease the cost of <a href="/facts/Municipal_infrastructure/SXrgjojz">municipal infrastructure</a>.

Tower block open-in-new

Tower block