History

Throughout most of human history, the majority of human settlements developed as mixed-use environments. Walking was the primary way that people and goods were moved about, sometimes assisted by animals such as horses or cattle. Most people dwelt in buildings that were places of work as well as domestic life, and made things or sold things from their own homes. Most buildings were not divided into discrete functions on a room by room basis, and most neighborhoods contained a diversity of uses, even if some districts developed a predominance of certain uses, such as metalworkers, or textiles or footwear due to the socio-economic benefits of propinquity.

People lived at very high densities because the amount of space required for daily living and movement between different activities was determined by walkability and the scale of the human body.

This was particularly true in cities, and the ground floor of buildings was often devoted to some sort of commercial or productive use, with living space upstairs.

This historical mixed-used pattern of development declined during industrialization in favor of large-scale separation of manufacturing and residences in single-function buildings. This period saw massive migrations of people from rural areas to cities drawn by work in factories and the associated businesses and bureaucracies that grew up around them.

These influxes of new workers needed to be accommodated and many new urban districts arose at this time with domestic housing being their primary function. Thus began a separating out of land uses that previously had occurred in the same spaces.

Furthermore, many factories produced substantial pollution of various kinds. Distance was required to minimize adverse impacts from noise, dirt, noxious fumes and dangerous substances. Even so, at this time, most industrialized cities were of a size that allowed people to walk between the different areas of the city.

These factors were important in the push for Euclidian zoning premised on the compartmentalization of land uses into like functions and their spatial separation. In Europe, advocates of the Garden City Movement were attempting to think through these issues and propose improved ways to plan cities based on zoning areas of land so that conflicts between land uses would be minimized. Modernist architects such as Le Corbusier advocated radical rethinking of the way cities were designed based on similar ideas, proposing plans for Paris such as the Plan Voisin, Ville Contemporaine and Ville Radieuse that involved demolishing the entire center of the city and replacing it with towers in a park-like setting, with industry carefully sited away from other uses.

In the United States, another impetus for Euclidian zoning was the birth of the skyscraper. Fear of buildings blocking out the sun led many to call for zoning regulations, particularly in New York City. Zoning regulations, first put into place in 1916, not only called for limits on building heights, but eventually called for separations of uses. This was largely meant to keep people from living next to polluted industrial areas. This separation, however, was extended to commercial uses as well, setting the stage for the suburban style of life that is common in America today. This type of zoning was widely adopted by municipal zoning codes.

With the advent of mass transit systems, but especially the private automobile and cheap oil, the ability to create dispersed, low-density cities where people could live very long distances from their workplaces, shopping centers and entertainment districts began in earnest. However, it has been the post-second World War dominance of the automobile and the decline in all other modes of urban transportation that has seen the extremes of these trends come to pass.

Benefits

Throughout the late 20th century, it began to become apparent to many urban planners and other professionals mixed-use development had many benefits and should be promoted again. As American, British, Canadian and Australian cities reindustrialized, the need to separate residences from hazardous factories became less important. Completely separate zoning created isolated "islands" of each type of development. In most cases, the automobile had become a requirement for transportation between vast fields of residentially zoned housing and the separate commercial and office strips, creating issues of Automobile dependency. In 1961, Jane Jacobs' influential The Death and Life of Great American Cities argued a mixture of uses is vital and necessary for a healthy urban area.

Zoning laws have been revised accordingly and increasingly attempt to address these problems by using mixed-use zoning. A mixed use district will most commonly be the "downtown" of a local community, ideally associated with public transit nodes in accordance with principles of Transit-oriented development (TOD) and New urbanism. Mixed use guidelines often result in residential buildings with street front commercial space. Retailers have the assurance they will always have customers living right above and around them, while residents have the benefit of being able to walk a short distance to get groceries and household items, or see a movie.