Clear, accessible definitions for common urban planning terms.
What Is Exclusionary Zoning?
Criticized as a key factor in perpetuating housing inequality in the United States, exclusionary zoning refers to a range of policies that, explicitly or implicitly, seek to prevent people of certain races, ethnicities, or income levels from buying homes in specific neighborhoods.
The practice of allowing the development of very few uses in a neighborhood is referred to as exclusionary zoning.
Zoning is a planning tool that regulates land use, including how land can be developed, the type and size of buildings that can be built, and how buildings relate to their surroundings and the public realm. Zoning grew in popularity in the early 20th century as cities sought to separate dangerous or polluting uses (such as manufacturing and waste disposal) from residential areas and maximize the social utility of grouping certain uses together. Social reformers in the early 1900s proposed zoning as a tool to exclude undesirable uses (such as noxious industrial facilities), reduce urban congestion, protect public welfare, and prevent the spread of slums.
However, since their inception, American zoning ordinances were also used as a tool to maintain racial homogeneity and exclude "undesirable" residents, sometimes outright banning specific ethnic groups, thus institutionalizing housing inequality. In 1910, Baltimore passed one of the first racial segregation laws, prohibiting Black people from moving into white-majority areas and vice-versa. Other cities passed similar ordinances until 1917, when the practice of racial zoning was declared unconstitutional in the case of Buchanan v. Warley. Exclusionary zoning persisted in more insidious ways and became a defining characteristic of mid-century America's suburbanization and white flight, including single-family zoning. Single-family zoning originated in the famously liberal enclave of Berkeley, California, where the Elmwood neighborhood adopted single-family zoning in 1916, effectively setting up the area to exclude lower-income households into the present day.
By the 1960s, the term "exclusionary zoning" had come to denote the detrimental discriminatory effects of planning and land use policies of the 20th century. In 1959, the Virginia Supreme Court struck down a local zoning ordinance that raised the minimum lot size in a portion of Fairfax County from one half to two acres, effectively excluding anyone without the means to purchase a larger lot. In 1965, Pennsylvania's Supreme Court similarly denied a zoning law in Eaton Township, asserting that "zoning is a means by which a governmental body can plan for the future—it may not be used as a means to deny the future." While exclusionary zoning was intended to protect neighborhoods and create rational use-based districts, history has shown that it has also had the effect of excluding residents by race and class.
As downtowns revitalized and the wealthy flocked back to urban centers in the last several decades, exclusionary zoning took on different forms. Modern exclusionary zoning mechanisms can include restrictions on housing type and supply, parking requirements, building setbacks, environmental review, historic preservation, design review, and impact fees, which limit the number of available units and drive housing costs up, indirectly excluding low- and middle-income households by limiting development to single-family homes. The preference for single-family residential districts has also led to explosive sprawl and a dearth of amenities such as corner stores or pharmacies, making residents dependent on cars for basic necessities.
As anti-development, anti-density measures spread, low-income families are increasingly pushed out of desirable neighborhoods close to transit and job centers. Prohibitions on the construction of Accessory Dwelling Units (also known as "granny flats") and the subdivision of single-family homes also prevent landowners from increasing the number of available units. In 2015, Seattle's Housing Affordability and Livability Agenda (HALA) report criticized the city's preferential treatment of single-family lots as one of the "largest obstacles to equity and affordability." According to some researchers, such anti-growth policies benefit the wealthy and bring "large, private, concentrated gains offset by even greater, public, distributed costs."