Zoning is a term used in urban planning for a system of land-use regulation in various parts of the world, including North America, the United Kingdom, and Australia. The word is derived from the practice of designating permitted uses of land based on mapped zones which separate one set of land uses from another. Zoning may be use-based (regulating the uses to which land may be put), or it may regulate building height, lot coverage, and similar characteristics, or some combination of these.
Zoning may include regulation of the kinds of activities which will be acceptable on particular lots (such as open space, residential, agricultural, commercial or industrial), the densities at which those activities can be performed (from low-density housing such as single family homes to high-density such as high-rise apartment buildings), the height of buildings, the amount of space structures may occupy, the location of a building on the lot (setbacks), the proportions of the types of space on a lot (for example, how much landscaped space and how much paved space), and how much parking must be provided. The details of how individual planning systems incorporate zoning into their regulatory regimes varies though the intention is always similar. For example, in the state of Victoria, Australia, land use zones are combined with a system of planning scheme overlays to account for the multiplicity of factors that impact on desirable urban outcomes in any location.
Euclidean zoning is utilized by some municipalities because of its relative effectiveness, ease of implementation (one set of explicit, prescriptive rules), long-established legal precedent, and familiarity to planners and design professionals.
However, Euclidean zoning has received heavy criticism for its lack of flexibility and institutionalization of now-outdated planning theory (see below).
The appeal of performance zoning lies in its high level of flexibility, rationality, transparency and accountability. Performance zoning can avoid the sometimes arbitrary nature of the Euclidian approach, and better accommodates market principles and private property rights with environmental protection. However, performance zoning can be extremely difficult to implement and can require a high level of discretionary activity on the part of the supervising authority leading to the potential for disenfranchisement among negatively affected stakeholders.
Incentive zoning allows for a high degree of flexibility, but can be complex to administer. The more a proposed development takes advantage of incentive criteria, the more closely it has to be reviewed on a discretionary basis. The initial creation of the incentive structure in order to best serve planning priorities can also be challenging and often requires extensive ongoing revision to maintain balance between incentive magnitude and value given to developers.
Design-based codes offer considerably more flexibility in building uses than do Euclidean codes, but, as they are comparatively new, may be more challenging to create. When form-based codes do not contain appropriate illustrations and diagrams, they have been criticized as being difficult to interpret.
One example of a recently adopted code with design-based features is the Land Development Code adopted by Louisville, Kentucky in 2003. This zoning code creates "form districts" for Louisville Metro. Each form district intends to recognize that some areas of the city are more suburban in nature, while others are more urban. Building setbacks, heights, and design features vary according to the form district. As an example, in a "traditional neighborhood" form district, a maximum setback might be 15 feet from the property line, while in a suburban "neighborhood" there may be no maximum setback.
Development control or planning control is the element of the United Kingdom's system of town and country planning through which local government regulates land use and new building. It relies on the "plan-led system" whereby development plans are formed and the public consulted. Subsequent development requires planning permission, which will be granted or refused with reference to the development plan as a material consideration.
There are 421 Local Planning Authorities (LPAs) in the United Kingdom. Generally they are the local borough or district council or a unitary authority. Development involving mining, minerals or waste disposal matters is dealt with by county councils in non-metropolitan areas. Within national parks, it is the National Park Authority that determines planning applications.
Statutory planning otherwise known as town planning, development control or development management, refers to the part of the planning process that is concerned with the regulation and management of changes to land use and development.
New Zealand's planning system is grounded in effects-based Performance Zoning under the Resource Management Act.
In 1916, New York City adopted the first zoning regulations to apply city-wide as a reaction to construction of The Equitable Building (which still stands at 120 Broadway). The building towered over the neighboring residences, completely covering all available land area within the property boundary, blocking windows of neighboring buildings and diminishing the availability of sunshine for the people in the affected area. These laws, written by a commission headed by Edward Bassett and signed by Mayor John Purroy Mitchel, became the blueprint for zoning in the rest of the country, partly because Bassett headed the group of planning lawyers which wrote The Standard State Zoning Enabling Act that was accepted almost without change by most states. The effect of these zoning regulations on the shape of skyscrapers was famously illustrated by architect and illustrator Hugh Ferriss.
The constitutionality of zoning ordinances was upheld in 1926. The zoning ordinance of Euclid, Ohio was challenged in court by a local land owner on the basis that restricting use of property violated the Fourteenth Amendment to the United States Constitution. Though initially ruled unconstitutional by lower courts, the zoning ordinance was upheld by the U.S. Supreme Court. In doing so, the Court accepted the arguments of zoning defenders that it met two essential needs. First, zoning extended and improved on nuisance law in that it provided advance notice that certain types of uses were incompatible with other uses in a particular district. The second argument was that zoning was a necessary municipal-planning instrument. By the late 1920s most of the nation had developed a set of zoning regulations that met the needs of the locality.
New York City went on to develop ever more complex set of zoning regulations, including floor-area ratio regulations, air rights and others according to the density-specific needs of the neighborhoods.
Among large populated cities in the United States, Houston is unique in having no zoning ordinances. Houston voters have rejected efforts to implement zoning in 1948, 1962 and 1993. However, land use is still very much regulated in Houston: up until 1999, single-family homes (which includes 98% of all housing stock) had to occupy 5,000 square feet of land. Apartment buildings currently must have 1.33 spaces per bedroom, and 1.25 for each efficiency. Some have argued that this sort of regulation has similar effects as zoning, and therefore can be regarded as a sort of roundabout zoning.