Planned unit development

A planned unit development (PUD) is a type of flexible, non-Euclidean zoning device that redefines the land uses allowed within a stated land area. PUDs consist of unitary site plans that promote the creation of open spaces, mixed-use housing and land uses, environmental preservation and sustainability, and development flexibility. Areas rezoned as PUDs include building developments, designed groupings of both varied and compatible land uses —such as housing, recreation, commercial centers, and industrial parks— within one contained development or subdivision. Developed areas vary in size and by zoned uses, such as industrial, commercial, and residential. Other types of similar zoning devices include floating zones, overlay zones, special district zoning, performance-based codes, and transferable development rights.

History

The conceptual origins of PUDS surround the 1926 enactment of the Model Planning Enabling Act of 1925 by the Committee on the Regional Plan of New York, which allowed for the decisions of planning boards and commissions to precede decisions required by local zoning regulations. Specifically, Section 12 of the Model Planning Enabling Act authorized planning boards and commissions to reasonably modify or change development plans and limited average population density and total land area covered by buildings. Similarly, Sections 14 and 15 of the Standard City Planning Enabling Act of 1928 allowed for planning commissions to authorize PUDs, upon an agreement between the government and developers on the PUD’s design principles and its impact onto both the surrounding community and economy.

The physical origins of PUDs are rooted in the increased suburbanization of the mid-twentieth century, during which the oldest forms of PUDs in America appeared shortly after World War II in the Levittown and Park Forest developments. Increased implementations of PUDs were in response to both the lack of aesthetic variation among suburban homes and the increasing need for higher suburban density to accommodate rising population sizes. PUDs resolved the problems of large-scale, suburban development in multiple, separate land uses were efficiently combined, preserving valuable open space and suburban aesthetics within specific site parameters limitations. The first zoning evidence of PUD was created by Prince George's County, Maryland in 1949, in which the developmental unit consisted of multiple land uses, in contrast to the county's previous commitment to single-land use Euclidean zoning. It "permit[ted] the development of a large tract of land as a complete neighborhood unit, having a range of dwelling types, the necessary local shopping facilities and off-street parking areas, parks, playgrounds, school sites, and other community facilities". Alexandria, Virginia, in 1952, as an amendment to its city code, provided for a "Community Unit Plan", with the intent to provide for planned community facilities and open space development with new residential building. One of the first modern uses of the term "planned unit development" appears in San Francisco's code of ordinances in 1962.

The usage of PUDs in new American communities have been, in part, the result of some international influence; British towns, like Reston, England, in the 1950s attempted to increase their economic base through the integration of industrial elements into the area. Though American new communities had to attract industry post-development of residential sectors, American new communities had similar economic needs to these British towns and, consequently, used PUDS to increase the percent of allowed industrial acreage relative to residential and nonresidential acreage.

Current definitions

PUD is a means of land regulation that promotes large scale, site-specific, mixed-use land development. PUDs are a very flexible form of zoning, as compared to Euclidean zoning, in that PUDs promotes innovative and creative design, can promote environmental conservation and affordable housing, clustering and increased density. Where appropriate, this type of development promotes:

• Upfront completion of project plans before development begins[][]
• An mixture of both land uses —such as those of commercial and industrial natures— and dwelling types that is more innovative than standard zoning ordinances[][]
• The clustering of residential land uses provides public and common open space
• Environmentally friendly preservation of sensitive lands, such as hills or wetlands, that would otherwise have been developed
• Reduction of greenhouse gas emissions if PUD prioritizes walkability alongside mixed uses
• Reduction of development and administrative costs, particularly infrastructure costs like those of streets, driveways, and water and sewer lines
• Increased administrative discretion to a local professional planning staff while setting aside present land use regulations and rigid plat approval processes
• The enhancement of the bargaining process between the developer and government municipalities
• Increased population densities and reduced street widths
• increase in available community amenities —like bike trails and recreation centers— and natural open spaces[][]

Frequently, PUDs take on a variety of forms ranging from small clusters of houses combined with open spaces to new and developing towns with thousands of residents and various land uses.

Mixtures of land uses

In PUDs, the zoning of districts becomes very different from what was standard under the Standard Zoning Enabling Act. Historically, the districts were very narrow in type and large in area. Within PUDs, zoning becomes much more integrated with multiple land uses and districts being placed on adjacent land parcels.

Residential properties in PUDs are by far the most numerous and occupy the largest land areas. PUDs tend to incorporate single-family residential uses in proximity to two-family units and multiple-family dwellings to form a larger diversified neighborhood concept. Schools, churches, retirement homes, hospitals, and recreation facilities begin to find their way into residential districts. Residential districts also tend to use the best land in the community and the most favorable sites are protected from commercial and industrial uses.

Grouping shopping districts by service area is a first step in returning to the neighborhood concept. Land is reserved for regional, community, and local shopping clusters with some specific restrictions based on market experience and on what types of business intend to locate at each development. Local shopping districts with sufficient provisions for off-street parking, height restrictions, and traffic control are not frequently found surrounded by residential areas.

Industrial standards now help to reduce the journey for employees to work. Nowadays, there tends to be environmental and performance regulations that cut back on the amount of nuisance to surrounding areas adjacent to industrial districts. With sufficient setbacks, off-street parking, and height regulations, industrial locations adjacent to residential zones are usually looked to as an overall community goal. PUDs do not normally have large numbers of industrial districts, but if so, they tend to be geared more towards light industry.

A planned residential unit development (PRUD) (sometimes planned unit residential development (PURD)) is a variant form of PUD where common areas are owned by the individual homeowners and not a homeowners association or other entity. A PURD is considered the same as a PUD for planning commission purposes and allows for flexibility in zoning and civic planning.

Maintenance of common areas

In most PUDs, individual owners have full ownership of their homes and buildings, making them the responsible party for maintenance. Governing documents of homeowners associations within PUDs often delegate most of the maintenance responsibilities to the owners, assuming the least amount of responsibility possible.

Design principles

Minimum Parcel Size

The minimum parcel size requirement can be in regards to either dwelling units or acres and can vary depending on both the type and location of a development. Given that minimum parcel sizes are a factor rarely necessary for project approval, maximum density requirements are more often used instead, focusing on either a maximum number of units per acre or a minimum lot acre per each dwelling unit.

Uses Permitted

Uses permitted is determined by allotting certain percentages of land use to residential, commercial, and industrial uses. Oftentimes, the amount allotted is dependent on the percentage of residential uses relative to non-residential uses within a defined area.

Density

Given that PUDs focus on integrating mixed uses into a specified area, density is calculated based on the Federal Housing Act’s Land Use Intensity (LUI) rating, which encompasses floor area, open space, livability, and recreational spaces within a single, numerical rating.

Houses and placement of houses

Houses in PUDs often include access to a large shared open space surrounding the house as well as a smaller private yard. These large protected open spaces are created by the layout of the buildings and are intended for use by all residents of the developments. Different housing types (single-family, two-family, multiple-family) are often mixed rather than separated as is done in conventional development

Usable, Public Open Space

There are multiple provisions PUDs must include in regards to available open spaces, which include, upon conditional approval, those concerning quantity, location, and maintenance of public areas. Approval for such provisions can be satisfied by one of the following: satisfying a minimum acreage requirement relative to a specific number of dwelling units or a direct percentage of gross acreage; approval from a planning board on the proposed location of the public, open space; or cosigned maintenance agreements between residents —regardless of whether it be by a municipality or an organized residential community, like a homeowner' association or a community trust. The requirement of these aforementioned revisions is to ensure that open, public land, facilities, amenities, and necessities are well-kept for ease of public use and accessibility.

Streets

Street patterns can be used to change the neighborhood character of a residential community, particularly by allowing developers to flexibly arrange buildings without having to adhere to non-PUD zoning regulations. Most non-PUD development focuses on obtaining maximum frontage for lot sizes and maximum flow of traffic on all streets. However, in order to dispel the monotony of the typical grid plan street pattern, PUDs often employ a hierarchy of street types based on usage. Wide, curvilinear, and cul-de-sac street patterns are such examples. The usage of these street, round street patterns allow developers to cluster buildings and maximize available open space. Local streets serve only residences and have a low traffic volume, while collector streets connect local streets to arterials, which are the major routes of travel throughout a PUD.

Sidewalks and pedestrian ways

Sidewalks and pedestrian ways of PUDs supplement and complement street systems in establishing the character of the neighborhood. Sidewalks are located on at least one side of every street to enable the walkability of the developments. Circulation systems are provided to link residential groupings, open space areas, schools, and local shopping areas.

Combining design features

It is in the ability to design each of these components simultaneously that makes PUDs unique and effective. Each of the elements work together to enhance the whole. This represents a major advantage over traditional zoning practices that force lots to be planned in accordance with broad rules that may allow for some incompatibility.

References

• Burchell, Robert. Planned Unit Development: New Communities American Style. New Jersey: MacCrellish & Quigley, 1972.
• New York City Planning Commission. Planned Unit Development. New York: Planning Department, 1968.