Module 3: Zones, Zoning Rules and Exemptions

In the last module, we examined the origins of zoning laws in the United States, the legal foundations for zoning laws and significant court decisions that have construed constitutional issues connected to zoning. This module continues our examination by focusing on the types and purposes of zones that municipalities use in urban planning.

Types of Zones

Zoning laws ordinarily have two main components:

1.     a zoning map that identifies what kinds of zones apply to land parcels under the municipality’s jurisdiction, and

2.     regulations governing the uses each zone permits, as well as requirements for allowable improvements such as buildings, parking lots, yards and signs.

Many systems of zoning rules are placed online by their municipalities, with some sites providing interactive assistance to visitors seeking to learn permitted uses and how to apply for property development licenses and permits.[1] In addition to mapping and identifying zones, zoning ordinances establish the government bodies that define, review and enforce zoning regulations. They also set forth procedures to apply for inconsistent uses within a given zone and to appeal zoning decisions.

The base purposes of zoning are twofold: to separate activities that do not go well together, such as keeping residential neighborhoods away from industrial areas, and as a framework to guide the growth of a municipality according to a larger land use scheme such as a comprehensive plan. The earliest types of zones in the United States, dating back to the zoning ordinances first enacted in the early 20^th Century, were simple in purpose and limited in number: residential, industrial and commercial. As urban planning has evolved over the past 100 years, so too has zoning become more sophisticated in concept and application.

Let’s look at the zone types commonly used today:

Residential zones do more than set aside space for people to live. Given the multiple forms of residential housing, it could become chaotic and unsightly if condominiums, apartments, motels, hotels, houses and mobile homes become jumbled together without any forethought to aesthetics, population density or livability. To avoid such confusion and to promote consistency in housing areas, zoning ordinances refine residential zones into subzones or districts with more tightly defined requirements that consider different ways people reside: single family homes, duplexes, apartments, hotels and motels, assisted care facilities and more.

Because zoning laws are state and local in origin, and can vary in their terms, anyone seeking to use or develop land subject to zoning requirements should consider how the applicable law identifies the permissible uses. For example, a city zoning ordinance may allow residential zones to be divided into districts. The code “A-2.5A” may refer to a district restricted to one-family detached homes with lot sizes of at least 2.5 acres. The district with an “A-5” code may be for detached houses on lot sizes of 5,000 square feet; code “B” for one and two-family detached and attached homes; “R2” for townhomes, “MH” is for mobile homes, and so on.[2]

Residential zoning laws also provide important information governing the construction, dimensions and other details of improvements. Some of the particulars that residential zones consider include:

• How many subdivisions or districts can exist within a zone
• How many structures can be built
• Minimum setback requirements
• Height, square footage and number of rooms restrictions
• Transportation and access requirements, including parking
• Drainage requirements
• Public utility easements
• Building design and landscaping
• Restrictions, if any, on home-based businesses; and
• Restrictions on the types and numbers of animals that may be kept.

The significance of these requirements is their impacts on the municipality’s decision whether to permit a proposed use or development. The more these comply with the requirements, the more likely they will meet with approval.

Commercial zoning is for businesses that ordinarily have public interaction. These include retail stores, restaurants, bars, nightclubs and offices. Hotels and motels can fall under the residential or commercial category. Like residential zones, commercial zones can be broken down into subdivisions with more specific permitted uses. Commercial zoning laws can also restrict where some businesses can locate, such as prohibiting adult entertainment enterprises or establishments that serve alcohol from being situated near schools or places of worship.[3]

Industrial zones are similar to commercial zones in the sense that both involve economic activity. Unlike commercial businesses, however, those found in industrial zones are less likely to serve customers. Industrial uses include factories, warehouses, airports and seaports. As commercial zones can restrict some kinds of businesses from operating near places that would find their presence objectionable, a concern of industrial zoning is to ensure that incidental effects of the activities, such as noise and air pollution, do not interfere with nearby residential or commercial activities.[4]

Other Zone Types

Although agricultural and rural land uses may seem inconsistent with urban planning, these types of zones play roles in shaping the growth of a municipality by protecting productive agricultural lands and ranges from "urban sprawl” as the town or city expands. Agricultural zones often restrict or prohibit non-farming activities and limit the number of residences that can be built. Rural zones are similar to agricultural zones; the main difference is that rural zones are often connected with animals instead of farming (such as setting aside grazing lands for livestock).

Municipalities that have existed long enough can have buildings that deserve preservation for their historic values. Historical zones and districts restrict owners and occupiers of historic buildings from demolishing them or altering them from their original states (except for repairs and restorations). Historic zones and districts can intersect with state and federal guidance identifying buildings of historic significance, such as the National Register of Historic Places.[5]

Aesthetic zoning serves to preserve the condition of existing land and buildings by limiting development of new structures and restricting activities that would be inconsistent with those existing buildings. Aesthetic zones and districts can also serve environmental preservation purposes by restricting development in areas like flood plains and shorelines.

Spatial zones are used by some municipalities to plan for large-scale uses, like airports, shopping malls, stadiums, sports complexes and power generation facilities.

Municipalities are free to define their own zones to suit their needs. Sometimes, especially in downtown areas, zones do not fit neatly into single categories. Mixed zones allow for blending uses of more than one type of zone into a single area, such as commercial and residential or commercial and industrial. For example, in cities that are subject to urban growth boundaries, many multi-story commercial buildings do double-duty: they feature office and retail space on the lower floors and residential spaces on the upper floors.[6] Mixed use zoning is the mechanism to permit these otherwise potentially inconsistent uses.

Single-Use (Euclidian) Zoning

Aside from usage-based identification, another way to categorize zones is by the number of uses they can be put to. Single use zoning, colloquially known as “building block” or “Euclidian” zoning (based on the US Supreme Court case of that name that held zoning to be a constitutional exercise of police power)[7] is the most commonly used zoning type in the United States.

As the oldest and most established zoning system in the United States, single-use zoning offers benefits to urban planners including relative ease of design and implementation, well-developed statutory models and case law decisions to use for guidance when drafting zoning ordinances, and its familiarity among most urban planners.

A variation of single-use zoning is “Euclidian II” zoning. Although this zoning method is based on the same types of zones as single use, it adds some additional zone types (such as transportation and utilities) and categorizes zones into the categories of public, semi-public and private. Another characteristic of Euclidian II zoning is its more liberal use of mixed zoning. 

“Smart zoning” is another type of single-use zoning that uses “floating zones,” wherein a zone’s desired characteristics are known but the zone is not set on the map until circumstances require it and suitable land is available. This type of zoning is often used for projects appropriate for spatial zones. It may also use “cluster zones” or “planned use development districts,” which are mixed-use residential and commercial zones situated close together to facilitate urban planning and to maximize the availability of surrounding open spaces.

Critics of single-use zoning cite drawbacks inherent in its age, such as inefficient land use that results in encroachment upon surrounding areas (“urban sprawl”), and over-reliance on cars that creates livability problems such as traffic, congestion and environmental degradation in the form of air and noise pollution. Some critics claim that single-use zones also contribute to urban decay and to racial and economic segregation.

Performance zoning adds site and activity criteria to create quantifiable standards for land development. The purpose of these standards is to better enable municipalities to minimize the adverse effects on adjacent properties. These zones have strong connections to building codes and environmental standards applicable to the type of activity. Residential zone standards focus on preserving natural resources while maximizing population density and open spaces while industrial standards concentrate on reducing noise, air pollution and other nuisances connected with manufacturing activity.[8]

Incentive zoning encourages developers to undertake public benefit improvements in return for receiving additional benefits from the municipality. For example, in exchange for being able to increase housing density, the developer may need to agree to fund improvements nearby like affordable housing, road construction or repairs or other public amenities.

Form-based zoning departs from single-use and other use-based zones to emphasize how a zone’s mix of buildings and the particulars of those buildings (such as  building frontages, height, number of floors, architectural and landscaping standards) affects the municipality’s larger comprehensive plan.[9] The purpose of form-based zoning is to achieve a community’s desired look and feel and to direct developers to plan for structures, streets and open spaces consistent with that desire.[10] Form-based zoning is not as concerned with preventing inconsistent uses as it is with promoting a coherent and consistent vision for the municipality.

Exemptions from Zoning Regulations

Zoning ordinances must consider the human element in urban planning and development. Even the most carefully considered and comprehensive zoning laws cannot anticipate how some people may need to act outside of its restrictions. When this happens, it may be possible to avoid or resolve legal conflicts by creating an exception to the zoning law to permit the use in question.

One way to resolve a zoning conflict is for the landowner to request a variance from the applicable law. Zoning variances can allow owners to develop land when the shape of the lot or its other characteristics or the zoning law itself would prevent the owner from using the property in a way comparable to surrounding properties (called “area variances”), or permit what would otherwise be prohibited activities on the land (called “use variances”). [11]

Alternatively, zoning laws may allow for property uses if the property owner can show compliance with conditions that the municipality imposes. Some municipalities give property owners the right to apply for conditional use permits to authorize what would otherwise be impermissible uses without changing the nature of the zone itself. Conditional use zoning gives the owner a mechanism to ask for an existing zone to be reclassified to permit new or different uses.[12] Conditional use approval criteria can include whether the zoning ordinance provides for the proposed conditional use, whether the conditional use is necessary for the public welfare and convenience and whether it will significantly interfere with neighboring property uses.[13] Examples of conditional uses in residential zones include operating a business from a home and establishing a convenience store or gasoline station in a residential area.

Zoning ordinances can be prohibitive or permissive in nature. Prohibitive ordinances permit uses as long as the zoning law does not preclude them; permissive ordinances allow uses that the law expressly permits. An accessory use is one that is not itself mentioned in a permissive ordinance, but which is supportive of or connected to a permitted use. An example of an accessory use would be a garage attachment to a residence when the permissive zoning law does not expressly refer to garages.[14]

Sometimes a municipality can create or modify a zone in a way that is so inconsistent with the zones that surround it that the rationale for the zone becomes suspect. If the result benefits only the owner of the newly-created or modified use property and burdens surrounding properties, this is known as spot zoning.[15] Spot zoning is not per se impermissible, but it is subject to scrutiny using criteria similar to those for conditional uses: whether the use is consistent with the zoning ordinance and with the municipality’s comprehensive plan, whether it benefits anyone other than the land owner of the spot zoning use and whether the spot zoning has a connection with a legitimate power or purpose.

Resolution of disputes that involve variances, conditional or accessory uses and spot zoning go through the government body that the zoning law identifies to handle disputes, such as a planning commission, appeals board or city council. The dispute resolution process normally involves public notice and one or more hearings. Administrative appeals to hearing decisions are also possible.

If the property owner who is subject to a zoning dispute disagrees with the dispute resolution that issues from the statutory procedure, a judicial appeal may be the next step. Courts can review a zoning law based on the appropriate standard of legal or even constitutional scrutiny, such as whether the application of the law was reasonable or arbitrary and whether it had a reasonable connection to an exercise of police power.

In our next module, we will apply the concepts covered in the first three modules to municipal land use scenarios to illustrate how the urban planning process works from the submission of the initial development proposal through dispute resolution and adjudication.