Planopedia

Parking requirements are a form of land use regulation that prescribes a specific amount of parking to be provided by the developer of any new development. Parking requirements can include both minimums and maximum requirements, but parking minimums are standard in zoning codes across the United States, with very few exceptions, because most parking requirements in the United States are designed to ensure that every development includes sufficient parking to meet the expected demand for access to the building.

Planners determine parking requirements with a formula specific to the intended use of a building, usually set according to the number of bedrooms in a residential development, for example, or according to square footage for many kinds of commercial development.  

Parking requirements date back to the mid-20th century, a time defined by a rapid pace of urban and suburban development, an explosion in the number of cars worldwide, and the emergence of parking as a political cause that frequently determines the outcomes of local elections. Parking requirements are now common in both urban and suburban communities, despite a common association with the big box stores, giant malls, and commercial office parks of suburban locations. 

In cities, the adoption of parking requirements marks a very specific moment in development history, creating urban developments of dramatically different character than previously. Historic districts built before parking requirements tend to line the sidewalk with active uses on the ground floor, providing multiple pedestrian access points. After parking requirements, developments often include several floors of parking, separating active uses from the ground level and creating multiple pedestrian conflict points where provided for the ingress and egress of automobiles. The alternative, subterranean parking located below the building, can add tremendous, often prohibitive costs to a development. 

However developers decide to build the required amount of parking on a new development site, parking minimums bundle the cost of parking spaces into the cost of development, increasing the prices of all the goods and services sold at the site. Thus, parking requirements tend to be one of the primary factors for determining whether a new development has the finances to complete construction and generate revenue for operations after construction is complete.

Many local jurisdictions have been rethinking parking requirements in recent years, especially parking minimums, following the publication of the influential book, The High Cost of Free Parking, by Donald Shoup in 2005. The book argues that the status quo of minimum parking requirements in the United States subsidizes cars, increases vehicle miles travel, encourages sprawl and the separation of uses, worsens air pollution and greenhouse gas emissions, raises the cost of housing construction and thus the cost of renting or buying a home, prevents pedestrian mobility, and excludes low-income people from participation in the economy. The book accuses planners of relying on a one-size-fits-all formula that lacks scientific rigor in establishing parking requirements. 

In the first month of 2021, two cities in California, Sacramento and Berkeley, announced plans to remove minimum parking requirements to spur the development of more affordable housing stock. The city of Buffalo is generally acknowledged as the first city to remove parking requirements citywide, though many others have since followed. Other cities have accomplished incremental progress toward reducing minimum parking requirements with plans tailored to specific neighborhoods or types of uses. Adaptive reuse ordinances, which allow the renovation of historic buildings for contemporary uses, tend to rely on the developer's ability to either locate parking offsite, or avoid parking requirements altogether.

Parking requirements offer one of the most clear examples of the mutual influence of land use and transportation in planning. Designed to suit the demands of automobiles, parking requirements have had a massive influence on the way cities have been created and developed.