URBAN ZONING & LAND USE CONTROL

AR-309: ARCHITECTURE AND TOWN PLANNING (A&TP-B)
By:
RAVINDAR KUMAR
Assistant Professor
Department of Architecture and Planning
NED University of Engineering and Technology
Karachi

LECTURE NO: 21
TOPIC: URBAN ZONING & LAND USE CONTROL

INTRODUCTION TO URBAN ZONING[1]?
Zoning is a device of land use regulation used by local governments in most developed countries[2]. 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.

According to G. K. Hiraskar the zoning is defined as “process of making sections or division of city areas in different zones, to control the incompatible land uses, & prevent the misuse of land & buildings heights and densities of population at the initial stages”. According to Mr. Trevor Whitley who describes zoning in the Encyclopedia of Urban Planning; the zoning is the division of community into zones/districts as per present & potential use of properties for controlling & directing their landuse and development of the city.

According to W.PAUL Farmer and Julie A. Gibb, the “Zoning is the division of land according to building Design & use”. This definition is explained in the book “Introduction to Urban Planning” by Anthony. J. Catanese & James. C. Snyder. Definition they describe that, “comprehensive zoning is the division of total municipal land in to districts in which restrictions are imposed on the use of land.”

The zoning regulations are drafted & developed by the legislative authority and enforced by the municipal action. The legislative authority permits the municipality to apply constant and consistent pressure upon landowners to develop & use their land through the guidance of community plan and the public interest.

OBJECTIVES OF ZONING:
There are three major objectives of zoning i.e. conserving the value of its properties, assuring orderly community growth and safeguarding general public welfare. One of the major objectives of zoning legislation is to “Establish regulations which provides locations for all essential uses of land & buildings and to ensure that each use is located at most appropriate place”.

PURPOSE OF ZONING:
The main concern of zoning is with, the use of land & buildings, their height & volumes, proportions with the open spaces and density of population in each particular zone. The zoning is also used as an instrument for the implementation of plan on development of privately owned land & buildings rather than public land, buildings & facilities. The zoning attempts to group together the most compatible landuses.

SCOPE OF ZONING:
Theoretically, the primary purpose of zoning is to segregate uses that are thought to be incompatible. In practice, zoning is used to prevent new development from interfereing with existing residents or businesses and to preserve the "character" of a community. Zoning is commonly controlled by local governments such as counties or municipalities, though the nature of the zoning regime may be determined or limited by state or national planning authorities or through enabling legislation. In Australia, land under the control of the Commonwealth (federal) government is not subject to state planning controls.

The United States and other federal countries are similar. Zoning and urban planning in France and Germany are regulated by national or federal codes. In the case of Germany this code includes contents of zoning plans as well as the legal procedure. 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, such as how much landscaped space, impervious surface, traffic lanes, and parking must be provided. In Germany, zoning usually includes building design, very specific green space and compensation regulations.

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. Most zoning systems have a procedure for granting variances (exceptions to the zoning rules), usually because of some perceived hardship caused by the particular nature of the property in question. Basically, urban zones fall into one of five major categories: residential, mixed residential-commercial, commercial, industrial and special (e. g. power plants, sports complexes, airports, shopping malls etc.). Each category can have a number of sub-categories. In Germany, e. g., each category has a designated limit for noise emissions (not part of the building code, but federal emissions code). In the United States or Canada, for example, residential zones can have the following sub-categories:

R-1: Residential occupancies containing sleeping units where the occupants are primarily transient in nature, including: Boarding houses, Hotels, Motels
R-2: Residential occupancies containing sleeping units or more than two dwelling units where the occupants are primarily permanent in nature, including: Apartment houses, Boarding houses, Convents, Dormitories
R-3: Residential occupancies where the occupants are primarily permanent in nature and not classified as Group R-1, R-2, R-4 or I, including: Buildings that do not contain more than two dwelling units, Adult care facilities for five or fewer persons for less than 24 hours.
R-4: Residential occupancies shall include buildings arranged for occupancy as residential care/assisted living facilities including more than five but not more than 16 occupants.

WHAT IS THE IMPORTANCE AND NEED OF ZONING?
The zoning is important aspect of town planning because without zoning regulation, incompatible land uses occurs which causes problems of health & hygiene, environmental pollution’s congestion public safety & security etc. For example, industrial zone is mostly away from residential zone so as the residential areas should be secured from dangerous gases and smoke pollution, the business & commercial zone is also made away from residential zone so as the residential areas should be free from noise & road traffic. Simultaneously the population is also distributed in different zones differently so as the population should not be concentrated in one zone & situation of congestion or comity problems emerges i.e. utilities pressure etc. in addition the building heights are also controlled by zoning so as high-rise should not develop with low height housing because the high-rise cutoff the sun shine, & breeze which makes the life of residents uncomfortable i.e. in Chicago, New York, Bombay etc building cast long shadow. The zoning is important because it secures the orderly growth of town; promote heath & safety, increase utility, beauty and efficiency of town. Infect it is the very soul of successful Town Planning.

LANDUSE CONTROL:[3]
Land use is the human modification of natural environment or wilderness into built environment such as fields, pastures, and settlements. The major effect of land use on land cover since 1750 has been deforestation of temperate regions. More recent significant effects of land use include urban sprawl, soil erosion, soil degradation, salinization, and desertification. Land-use change together with use of fossil fuels, are the major anthropogenic sources of carbon dioxide, a dominant greenhouse gas. It has also been defined as "the total of arrangements, activities, and inputs that people undertake in a certain land cover type" (FAO, 1997a; FAO/UNEP, 1999).

MUNICIPAL LAND USE:
Each designation, known as a parcel’s zoning, comes with a list of approved uses that can legally operate on the zoned parcel. These are found in a government’s ordinances or zoning regulations.

LAND USE AND THE ENVIRONMENT:
Land use and land management practices have a major impact on natural resources including water, soil, nutrients, plants and animals. Land use information can be used to develop solutions for natural resource management issues such as salinity and water quality. For instance, water bodies in a region that has been deforested or having erosion will have different water quality than those in areas that are forested. According to a report by the United Nations' Food and Agriculture Organisation, land degradation has been exacerbated where there has been an absence of any land use planning, or of its orderly execution, or the existence of financial or legal incentives that have led to the wrong land use decisions, or one-sided central planning leading to over-utilization of the land resources - for instance for immediate production at all costs.

As a consequence the result has often been misery for large segments of the local population and destruction of valuable ecosystems. Such narrow approaches should be replaced by a technique for the planning and management of land resources that is integrated and holistic and where land users are central. This will ensure the long-term quality of the land for human use, the prevention or resolution of social conflicts related to land use, and the conservation of ecosystems of high biodiversity value.

HISTORY OF ZONING:
As far as the history of zoning is concerned, the origin /start & use of zoning took place in late 19th century. The first modern zoning ordinance was developed in New York City in 1916. However legally it was enforced n 1962 when us Supreme Court considered the legality of comprehensive zoning controls. They made a landmark decision in a case where the court discussed the need for and imposed pattern of landaus & concept of a comprehensive or Euclidean zoning. By the year 1930, several hundred localities has followed suit and had established their own zoning ordinances throughout USA.

ORIGINS AND HISTORY OF ZONING IN UNITED STATES:
Special laws and regulations were long made, restricting the places where particular businesses should be carried on. In the 1860s a specific State statute prohibited all commercial activities along Eastern Parkway (Brooklyn), setting a trend for future decades. In 1916, New York City[4] 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 Mitchell, 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 include 98% of all housing stock) had to occupy 5,000 square feet (460 m2) of land. Apartment buildings currently must have 1.33 parking spaces per bedroom. Some have argued that this sort of regulation has similar effects as zoning, and therefore can be regarded as a sort of roundabout zoning.

ZONING TYPES IN THE UNITED STATES:
Zoning codes have evolved over the years as urban planning theory has changed, legal constraints have fluctuated, and political priorities have shifted. The various approaches to zoning can be divided into four broad categories: Euclidean, Performance, Incentive, and Design-based.

EUCLIDEAN
Named for the type of zoning code adopted in the town of Euclid, Ohio, and approved in a landmark decision of the U.S. Supreme Court, Euclidean zoning codes are by far the most prevalent in the United States, used extensively in small towns and large cities alike.

STANDARD EUCLIDEAN
Also known as "Building Block" zoning, Euclidean zoning is characterized by the segregation of land uses into specified geographic districts and dimensional standards stipulating limitations on the magnitude of development activity that is allowed to take place on lots within each type of district. Typical types of land-use districts in Euclidean zoning are: residential (single-family), residential (multi-family), commercial, and industrial. Uses within each district are usually heavily prescribed to exclude other types of uses (residential districts typically disallow commercial or industrial uses). Some "accessory" or "conditional" uses may be allowed in order to accommodate the needs of the primary uses. Dimensional standards apply to any structures built on lots within each zoning district, and typically take the form of setbacks, height limits, minimum lot sizes, lot coverage limits, and other limitations on the "building envelope". 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.

EUCLIDEAN II
Euclidean II Zoning uses traditional Euclidean zoning classifications (industrial, commercial, multi-family, residential, etc.) but places them in a hierarchical order "nesting" one zoning class within another similar to the concept of Planned Unit Developments (PUD) mixed uses, but now for all zoning districts; in effect, adding a third dimension to flatland Euclidean zoning. For example, multi-family is not only permitted in "higher order" multi-family zoning districts, but also permitted in high order commercial and industrial zoning districts as well. Protection of land values is maintained by stratifying the zoning districts into levels according to their location in the urban society (neighborhood, community, municipality, and region). Euclidean II zoning also incorporates transportation and utilities as new zoning districts in its matrix dividing zoning into three categories: Public, Semi-Public and Private. In addition, all Euclidean II Zoning permitted activities and definitions are tied directly to the state's building code, Municode and the North American Industry Classification System (NAICS) assuring statewide uniformity. Euclidean II zoning fosters the concepts of mixed use, new urbanism and "highest and best use"; and, simplifies all zoning classifications into a single and uniform set of activities. It is relatively easy to transition from most existing zoning classification systems to the Euclidean II Zoning system.

PERFORMANCE
Also known as "effects-based planning" performance zoning uses performance-based or goal-oriented criteria to establish review parameters for proposed development projects in any area of a municipality. Performance zoning often utilizes a "points-based" system whereby a property developer can apply credits toward meeting established zoning goals through selecting from a 'menu' of compliance options (some examples include: mitigation of environmental impacts, providing public amenities, building affordable housing units, etc.). Additional discretionary criteria may also be established as part of the review process.

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
First implemented in Chicago and New York City, incentive zoning is intended to provide a reward-based system to encourage development that meets established urban development goals. Typically, a base level of prescriptive limitations on development will be established and an extensive list of incentive criteria will be established for developers to adopt or not at their discretion. A reward scale connected to the incentive criteria provides an enticement for developers to incorporate the desired development criteria into their projects. Common examples include FAR (floor-area-ratio) bonuses for affordable housing provided on-site, and height limit bonuses for the inclusion of public amenities on-site. 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.

FORM-BASED
Form-based codes offer considerably more flexibility in building uses than do Euclidean codes. Form based zoning regulates not the type of land use, but the form that that land use may take. For instance, form based zoning in a dense area may insist on low setbacks, high density, and pedestrian accessibility among other things. As another example, in a largely suburban single family residential area, uses such as offices, retail, or even light industrial could be permitted so long as they conformed (setback, building size, lot coverage, height, and other factors) to other existing development in the area. Form-based zoning relies on rules applied to development sites according to both prescriptive and potentially discretionary criteria. These criteria are typically dependent on lot size, location, proximity, and other various site- and use-specific characteristics.

Form based zoning also may specify desirable design features, however 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 sub-urban 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 (4.6 m) from the property line, while in a suburban "neighborhood" there may be no maximum setback. Since the concept of form based codes is relatively new, this type of zoning may be more challenging to enact.

ZONING ORDINANCES IN UNITED KINGDOM:
The zoning ordinances subdivide the city or town in Districts, each district then authorized with some specified uses, with building heights, bulk/volume, & set back requirements. In British planning no regulatory provision in made for zoning ordinance. They don’t have any general rules of zoning for potential application. However in the absence of any rules the local planning authority studies each zoning application on its merits with respect development plan. 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.

ZONING IN AUSTRALIA:
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.[5]

LAND USE CONTROL REGULATION IN JAPAN[6]:
In Japan, the zoning system is considered as the most important element in urban planning. Urban city planning area is divided into two areas: urban promotion area (UPA) and urban control area (UCA). UPA is the area in which the local government is to promote urbanization, and the rest are areas in which urbanization is controlled as UCA. There are a number of areas where zoning is not carried out, depending on the location. The development of such area requires permission from the government. In the UCA, development is basically prohibited, except for special cases such as agriculture and forestry. Japan has twelve different types of zones for commercial, industrial, and residential uses. Basically, Japan has regulations on the types of facilities that can be built in specific areas or specific zones. There are also regulations on floor ratio and building to land ratio.

CITY PLANNING AREA
City planning area is designated in the area to be planned and developed as a comprehensive unit. Approximately 100,000 Km2 or one quarter of the nation’s land (380,000 Km2) is designated as city planning area, which includes about 2,000 cities, towns, and villages. Some 114 million people or 92% of the total population live in the designated city planning area.

URBANIZED AREA AND URBAN CONTROLLED AREA
City Planning Area is divided into the two areas: 1) “Urbanized Area,” which includes existing urbanized areas and areas to be developed within next ten years; and 2) “Urban Controlled Area,” where urbanization is restricted. The urbanized and urban controlled areas are designated within the city planning area, which include three major metropolitan areas and the cities with a population of more than 100,000 persons. The urbanized areas amount to approximately 1.4 million ha in total, which occupies about 4% of the nation’s land area. Approximately 82 million people or 66% of the nation’s population live in the urbanized areas.

DEVELOPMENT PERMISSION
Any development with change of building/land form or use is required to obtain development permission. Technical standard of development permission is regulated in the City Planning Law. Under the Law, most of development actions are generally prohibited in urban controlled areas, with some exceptions. Demarcation of urbanized and urban controlled areas is occasionally reviewed.

LAND USE ZONING ORDINANCE
Land use zoning is designated on the basis of existing land use pattern and its future orientation. The zoning is classified into the three major categories: residential, commercial and industrial uses. There are twelve types of land use zoning. The type of building allowed to be developed is regulated by the zoning ordinance. The floor area ratio and building coverage ratio are also designated by the zoning ordinance. Land use zoning is designated in urbanized area, not in urban controlled area.

ZONING CLASSIFICATION:
The zoning is classified in three categories i.e. Use Zoning, Height Zoning and Density Zoning.

USE ZONING:
In use zoning city is divided into different sections/zones for various specific purposes. The use zoning is classified in six broad categories or sections i.e. Residential Zone, Institutional Zone, Industrial Zone, Civic Zone, Institutional Zone and Recreational Zone.

RESIDENTIAL ZONE:
It is the zone for housing of large number of people. The buildings developed in this zone are, detached single family houses, semidetached houses or duplexes, group housing, chawl, low, medium and high-rise flats or apartments and residential sky scrapers. This zone covers the area 40 to 50% of total away from business or Industrial zones. It needs privacy & use of green belt parks & fast communication facilities.

COMMERCIAL ZONE:
This covers area of 2% to 5%, having market, warehousing, storage spaces, go-downs, business offices, banks & residential spaces for employees. They should be located near traffic, transport & roadside.

INDUSTRIAL ZONE:
This covers area of % to 20%. This is most important zone after residential zone. This is located leeward of the town so that dangerous gases should not affect town population. This zone further divided in four categories i.e. Minor Industries, Light Industries, Medium Industries and Heavy Industries.

MINOR INDUSTRIES:
These are small industries, such as, bakeries, dairies & laundries these can be located near residential zone for the benefit of people.

LIGHT INDUSTRIES:
These are small factories such as glass, porcelain or Ice which only use electric power not solid fuel it’s not much real nuisance, so they can be located at the periphery of town.

MEDIUM INDUSTRIES:
These are large factories or industrial units such as cotton mills, oil mills, sugar mills which produce noisy environment & residential & commercial zone.

HEAVY INDUSTRIES:
These are large manufacturing industries or large heavy duty industrial units such as cement factory, steel factories and fertilizer plants that produce fumes & gases. Therefore these should be located in outskirts away forms town in leeward position.

CIVIC ZONE:
This zone covers area of 2% to 3%. It contains all public building i.e. town hall, courts, libraries, post office museum, auditoriums, banks etc. & housing for employees working there. These should be located at strategy locations where public access should be easier.

INSTITUTIONAL ZONE:
This is again located in a quite zone, having an area of 1% to 2%. It contains schools, college, university, & other research institutes etc.

RECREATIONAL ZONE:
This zone is located / planned with natural elements. This covers 15% to 20%. This provides healthy environment. It includes parks, play grounds, auditoriums, cinemas, theaters etc.

HEIGHT ZONING:
As discussed earlier, the height zoning is quite important for the purpose of good livable environment with appropriate sun light & Air movement. Simultaneously the control over height & volume of the buildings is also necessary for prevention from social evils and aesthetic beauty of the town that includes the cohesiveness among small & large buildings & to satisfy air / ground traffic rules. Because high-rises need specific considerations regarding movement of aero planes and to avoid narrow streets & traffic congestion.

Now there are various methods to control building volume & heights. Such as road widths / Air plane rules, bulk method rules etc.

ACCORDING TO MR. G. K. HIRASKAR:
The first major method to control building heights is through road widths / Air plain rule. Generally it should be 45o to 63.5o from the center of road to roof top edge of the building.

The other major method to control Building heights is bulk volume method in which building volume is controlled by making it equal to the volume of prism; where plinth area is considered as base & height equal to width of road.

=> 1/3 x AREA x HEIGHT

The third important method which is currently applied in most developed & underdeveloped countries are floor space index or (FSI). In this method the total floor area of building is controlled by relating it with the open space in the total plot area. In the building bye laws of KDA (in Karachi) it is termed as FAR or Floor Area Ratio.

The thumb rule in this regard is that “As much as the plot area as less is the covered area and as less is the plot area as much as the covered area”. It means that the covered area is inversely proportionate to plot area. If one read the KDA Building bye laws it will be evident that; for different plot size or at different locations different floor area ratios are applied.

DENSITY ZONING:
The density zoning is mainly related to population density, Gross density & net density; where the population density is population / unit area or acres of land, gross density is average density of population / unit area of residential zone including open spaces, schools, shops & institutions; Net density is average density / unit area of housing & roads.

The objective of density zoning is to control the overcrowding & concentration of population in some particular Area. In density zoning a town planner fix certain standards of gross & net densities for various areas which prohibit the collection of population in any particular zone. Now this control of population is achieved in three ways.

i) Fixing minimum size of plot for each house.
ii) Specifying nos. of houses per unit area.
iii) Fixing the ratio of total plot area v/s total buildup area.

ZONING POWERS:
The zoning power is mainly lying with local development authority, which enforces rules & regulations of zoning & makes changes in it from time to time. The zoning powers are mainly made at a liberal scale & they are not so rigid considering the benefits for the people living in a locality. For instance the existing industries which are not harmful for the health of people they are allowed as “Non-confirming” use even if they are undesirable.

However these industries are not allowed to expand in any case. In addition the policy will be to remove this industry by passage of time subject to provision of facilities in any industrial zone as an alternative. Some times it is necessary to have school, library, community hall, & shopping units in a residential zone. For which special permission is obtained form the local authority. However those factories / industries which produce noise & bad odors or smoke are strictly prohibited. Therefore conclusively the zoning powers are divided in three categories.

i) Uses permitted under “Non-conforming” Types.
ii) Uses which are permitted under “special approval by local authority.
iii) Uses which are strictly prohibited.

Finally the competent zoning authority should enforce zoning powers from time to time otherwise chaos will result in city which is evident in cities now a day. Zoning power is an effective tool available with a town planner to make his town-planning scheme successful.


REFERENCES:
[1] http://en.wikipedia.org/wiki/Zoning
[2] E.g., Lefcoe, George, "The Regulation of Superstores: The Legality of Zoning Ordinances Emerging from the Skirmishes between Wal-Mart and the United Food and Commercial Workers Union" (April 2005). USC Law, Legal Studies Research Paper No. 05-12; and USC Law and Economics Research Paper No. 05-12. http://www.bmvbs.de/ Town and Country Planning Act 1990
[3] http://en.wikipedia.org/wiki/Landuse
[4] http://www.nyc.gov/html/dcp/html/zone/zonehis.shtml
[5] Gleeson B. and Low N., Australian Urban Planning: New Challenges, New Agendas, Allen & Unwin, St Leonards, 2000.
[6] http://www.gdrc.org/uem/observatory/land-regulation.html