A
setback, sometimes called step-back, is a step-like recession in a
wallA wall is a usually solid structure that defines and sometimes protects an area. Most commonly, a wall delineates a building and supports its superstructure, separates space in buildings into rooms, or protects or delineates a space in the open air...
. Setbacks were initially used for structural reasons, but now are often mandated by land use codes.
History
Setbacks were used by ancient builders to increase the height of
masonryMasonry is the building of structures from individual units laid in and bound together by mortar; the term masonry can also refer to the units themselves. The common materials of masonry construction are brick, stone, marble, granite, travertine, limestone; concrete block, glass block, stucco, and...
structures by distributing gravity loads produced by the building material such as clay, stone or brick. This was achieved by regularly reducing the footprint of each level located successively farther from the ground. Setbacks also allowed the natural erosion to occur without compromising the structural integrity of the building. The most graphic example of a setback technique is the
step pyramidStep pyramids are structures which characterized several cultures throughout history, in several locations throughout the world. These pyramids typically are large and made of several layers of stone...
s of
MesopotamiaMesopotamia is a toponym for the area of the Tigris–Euphrates river system, largely corresponding to modern-day Iraq, northeastern Syria, southeastern Turkey and southwestern Iran.Widely considered to be the cradle of civilization, Bronze Age Mesopotamia included Sumer and the...
and
Ancient EgyptAncient Egypt was an ancient civilization of Northeastern Africa, concentrated along the lower reaches of the Nile River in what is now the modern country of Egypt. Egyptian civilization coalesced around 3150 BC with the political unification of Upper and Lower Egypt under the first pharaoh...
, such as the
Teppe Sialk zigguratTepe Sialk is a large ancient archeological site in a suburb of the city of Kashan, Isfahan Province, in central Iran, close to Fin Garden. The culture that inhabited this area has been linked to the Zayandeh Rud Civilization.-History:The Sialk mound was built around the 8th century BC...
or the
Pyramid of DjoserThe Pyramid of Djoser , or step pyramid is an archeological remain in the Saqqara necropolis, Egypt, northwest of the city of Memphis. It was built during the 27th century BC for the burial of Pharaoh Djoser by Imhotep, his vizier...
.
For centuries, setbacks were a structural necessity for virtually all multi-level load-bearing
masonryMasonry is the building of structures from individual units laid in and bound together by mortar; the term masonry can also refer to the units themselves. The common materials of masonry construction are brick, stone, marble, granite, travertine, limestone; concrete block, glass block, stucco, and...
buildings and structures. As
architectAn architect is a person trained in the planning, design and oversight of the construction of buildings. To practice architecture means to offer or render services in connection with the design and construction of a building, or group of buildings and the space within the site surrounding the...
s learned how to turn setbacks into an architectural feature, most setbacks were however less pronounced than in
step pyramidStep pyramids are structures which characterized several cultures throughout history, in several locations throughout the world. These pyramids typically are large and made of several layers of stone...
s and often skillfully masked by rich
ornamentationIn architecture and decorative art, ornament is a decoration used to embellish parts of a building or object. Large figurative elements such as monumental sculpture and their equivalents in decorative art are excluded from the term; most ornament does not include human figures, and if present they...
.
The introduction of a
steel frameSteel frame usually refers to a building technique with a "skeleton frame" of vertical steel columns and horizontal -beams, constructed in a rectangular grid to support the floors, roof and walls of a building which are all attached to the frame...
structural system in the late 19th century eliminated the need for structural setbacks. The use of a frame building technology combined with conveniences such as
elevatorAn elevator is a type of vertical transport equipment that efficiently moves people or goods between floors of a building, vessel or other structures...
s and motorized
water pumpWater Pump is one of the neighbourhoods of Gulberg Town in Karachi, Sindh, Pakistan. It is near main Water Pump that supplies fresh water to the city of Karachi....
s influenced the physical growth and density of buildings in large
citiesA city is a relatively large and permanent settlement. Although there is no agreement on how a city is distinguished from a town within general English language meanings, many cities have a particular administrative, legal, or historical status based on local law.For example, in the U.S...
. Driven by the desire to maximize the usable floor area, some developers avoided the use of setbacks, creating in many instances a range of fire safety and health hazards. Thus, the 38-story
Equitable BuildingThe Equitable Building is a 38-story office building in New York City, located at 120 Broadway in the Financial District of Lower Manhattan. A landmark engineering achievement as a skyscraper, it was designed by Ernest R. Graham and completed in 1915...
, constructed in
New YorkNew York is the most populous city in the United States and the center of the New York Metropolitan Area, one of the most populous metropolitan areas in the world. New York exerts a significant impact upon global commerce, finance, media, art, fashion, research, technology, education, and...
in 1915, produced a huge shadow, said to "cast a noonday shadow four blocks long" which effectively deprived neighboring properties of sun light.
Setbacks and urban planning
Today many
jurisdictionJurisdiction is the practical authority granted to a formally constituted legal body or to a political leader to deal with and make pronouncements on legal matters and, by implication, to administer justice within a defined area of responsibility...
s rely on
urban planningUrban planning incorporates areas such as economics, design, ecology, sociology, geography, law, political science, and statistics to guide and ensure the orderly development of settlements and communities....
regulations, such as zoning ordinances, which use setbacks to make sure that streets and yards are provided more open space and adequate light and air. For example, in high density districts, such as
ManhattanManhattan is the oldest and the most densely populated of the five boroughs of New York City. Located primarily on the island of Manhattan at the mouth of the Hudson River, the boundaries of the borough are identical to those of New York County, an original county of the state of New York...
in
New YorkNew York is the most populous city in the United States and the center of the New York Metropolitan Area, one of the most populous metropolitan areas in the world. New York exerts a significant impact upon global commerce, finance, media, art, fashion, research, technology, education, and...
, front walls of buildings at the street line may be limited to a specified height or number of stories. Above that height, the buildings are required to set back behind a theoretical inclined plane, called
sky exposure plane, which cannot be penetrated by the building's exterior wall. For the same reason, setbacks may also be used in lower density districts to limit the height of perimeter walls above which a building must have a pitched roof or be set back before rising to the permitted height.
In many cities, building setbacks add value to the interior real estate adjacent to the setback by creating usable exterior spaces. These setback
terracesA terrace is an outdoor, occupiable extension of a building above ground level. Although its physical characteristics may vary to a great degree, a terrace will generally be larger than a balcony and will have an "open-top" facing the sky...
are prized for the access they provide to fresh air,
skylineA skyline is the overall or partial view of a city's tall buildings and structures consisting of many skyscrapers in front of the sky in the background. It can also be described as the artificial horizon that a city's overall structure creates. Skylines serve as a kind of fingerprint of a city, as...
views, and recreational uses such as gardening and outdoor dining. In addition, setbacks promote fire safety by spacing buildings and their protruding parts away from each other and allow for passage of
firefighting apparatusA fire apparatus, fire engine, fire truck, or fire appliance is a vehicle designed to assist in fighting fires by transporting firefighters to the scene and providing them with access to the fire, along with water or other equipment...
between buildings.
In the
United StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
, setback requirements vary among
municipalitiesA municipality is essentially an urban administrative division having corporate status and usually powers of self-government. It can also be used to mean the governing body of a municipality. A municipality is a general-purpose administrative subdivision, as opposed to a special-purpose district...
. For example, the absence of sky exposure plane provisions in the Chicago Zoning Code makes the
ChicagoChicago is the largest city in the US state of Illinois. With nearly 2.7 million residents, it is the most populous city in the Midwestern United States and the third most populous in the US, after New York City and Los Angeles...
skylineA skyline is the overall or partial view of a city's tall buildings and structures consisting of many skyscrapers in front of the sky in the background. It can also be described as the artificial horizon that a city's overall structure creates. Skylines serve as a kind of fingerprint of a city, as...
quite different from the skyline of
New YorkNew York is the most populous city in the United States and the center of the New York Metropolitan Area, one of the most populous metropolitan areas in the world. New York exerts a significant impact upon global commerce, finance, media, art, fashion, research, technology, education, and...
where construction of tall buildings was guided by the zoning ordinance since 1916. The
New York City Zoning OrdinanceThe New York City 1916 Zoning Resolution was a measure adopted primarily to stop massive buildings such as the Equitable Building from preventing light and air from reaching the streets below...
also provided another kind of setback guideline, one that was intended to increase the amount of public space in the city. This was achieved by increasing the minimum setback at street level, creating in each instance an open space, often referred to as
plazaPlaza is a Spanish word related to "field" which describes an open urban public space, such as a city square. All through Spanish America, the plaza mayor of each center of administration held three closely related institutions: the cathedral, the cabildo or administrative center, which might be...
, in front of the building.
Additional References
- Delirious New York, by Rem Koolhaas. Monacceli Press, reprint 1997.
- A Pattern Language, by Christopher Alexander. Oxford University Press, 1977.
External links