CITY BLOCK

A 'city block', 'urban block' or simply 'block' is a central element of urban planning and urban design. A city block is the smallest area that is surrounded by streets. City blocks are the space for buildings within the street pattern of a city, they form the basic unit of a city's urban fabric. City blocks may be subdivided into any number of smaller lots or parcels of land usually in private ownership, though in some cases, it may be other forms of tenure. City blocks are usually built-up to varying degrees and thus form the physical containers or 'streetwalls' of public space. Most cities are composed of a greater or lesser variety of sizes and shapes of urban block. For example, many pre-industrial cores of cities in Europe, Asia and the Middle-east tend to have irregularly shaped street patterns and urban blocks, while cities based on grids have much more regular arrangements. The World's Smallest City Block is located in Dothan, Alabama at the intersection of North Appletree, Museum, and Troy street. This land triangle features a stop sign, a yield sign, a street sign, and a granite marker placed by the Camellia Garden Club on May 1, 1964 stating that the block is the World's Smallest City Block.

Contents

Grid plan

Superblock

Perimeter block

See also

References

Further reading

Grid plan

In most cities of the world that were planned, and did not develop and expand over a long period of time, streets are traditionally laid out on a grid plan, so that city blocks are square or rectangular. Using the perimeter block development principle, city blocks are developed so that buildings are located along the perimeter of the block, with entrances facing the street, and semi-private courtyards in the rear of the buildings.^[1] This arrangement is intended to provide good social interaction among people.
Since the spacing of streets in grid plans varies so widely among cities, or even within cities, it is impossible to generalize about the size of a city block. However, as reference points, the standard block in Manhattan is about 264 feet by 900 feet (about 80 meters by 271 meters), or slightly over five acres (two hectares); and in some U.S. cities standard blocks are as wide as 1/8 mile (660 feet or approximately 200 meters), or 10 acres (about 4 hectares) if square. While for example, the city blocks in the central city grid of Melbourne, Australia are 200m by 100m (approx. 656 feet by 328 feet).
In most areas, cities have grown in a more amorphous manner rather than being planned from the outset. For this reason, an even pattern of square or rectangular city blocks is very uncommon in much of Europe. New York City adopted the Commissioners' Plan of 1811 creating an early example of the modern grid plan. In much of the United States and Canada, the addressing systems follow a block and lot number system, in which each block of a street is allotted 100 building numbers.

Superblock

Superblocks were popular during the early and mid-20th century, arising from modernist ideas in architecture and urban planning. A superblock is much larger than a traditional city block, with greater setback for buildings, and is typically bounded by widely spaced, high-speed, arterial or circulating routes rather than by local streets. Superblocks are generally associated with suburbs, planned cities, and the urban renewal of the mid-20th century; that is, in areas in which a street hierarchy has replaced the traditional grid. In a residential area of a suburb, the interior of the superblock is typically served by cul-de-sac roads.
Urban planner Clarence Perry argued for use of superblocks and related ideas in his "neighborhood unit" plan, which aimed to organize space in a way that is more pedestrian-friendly and provided open plazas and other space for residents to socialize.^[2] In the 1930s, superblocks were often used in urban renewal public housing projects in American cities.^[3] In using superblocks, housing projects aimed to eliminate back alleys, which were often associated with slum conditions.
Superblocks are also used when functional units such as rail yards or housing projects are too big to fit in one block.

Perimeter block

A perimeter block is a type of city block which is built up on all sides surrounding a central space that is semi-private. They are usually between 4 and 7 storeys in height, and may contain a mixture of uses, with commercial or retail functions on the ground floor. Perimeter blocks are a key component of the many European cities and are an urban form that allows very high urban densities to be achieved without high-rise buildings.

See also

★ Census block

★ Minkowski space - One type of Minkowski space is sometimes known as "city-block space", with distance measured as Manhattan distance

★ Mixed-use development

★ Urban design

★ Urban planning

References

1. Designing the City: Towards a More Sustainable Urban Form, Frey, Hildebrand Frey, , , E & FN Spon, 1999,
2. Neighborhood Planning, Keating, W. Dennis, Norman Krumholz, , , Journal of Planning Education and Research, 2000
3. Regulating Place: Standards and the Shaping of Urban America, Ben-Joseph, Eran, Terry S. Szold, , , Routledge, 2005,

Further reading

★ Jacobs, J (1961) The death and life of great American cities