Urban consolidation

Urban consolidation describes the policy of constraining further development and population growth to within the boundaries of preexisting urban areas rather than expanding outward into suburban areas. Urban consolidation seeks to increase the population density of a given urban area by expanding upward, redeveloping preexisting buildings and lots, and constructing new facilities in available spaces. It is theorized that discouraging urban sprawl and encouraging further development of housing units in preexisting urban areas will lead to a net gain in social and economic prosperity (e.g. more accessible public transportation, more efficient use of public utilities, and increased affordability of housing).

There are broadly three kinds of urban consolidation: Market-led consolidation of existing residential areas involves residential redevelopment of established dwellings as well as non-residential land and buildings at higher densities than the metropolitan average. Transit-oriented development (or TOD) involves high-density residential and mixed-use buildings within walkable precincts around public transport nodes, often referred to as Activity centres. The third approach is to require that all new development on the urban fringe of existing metropolitan areas is at higher densities than the current average for those cities.

The term "urban consolidation" first appears in social science and urban planning literature around the late 19th and early 20th centuries. Much of the existing literature on urban consolidation comes from Australia; some of the world's first government-official urban consolidation policies were enacted in Sydney and Melbourne to increase construction of higher-density terrace housing in the late 19th century. Throughout the 20th century, implementation of urban consolidation policies appears to come in 'waves', separated by population surges stemming from major events like World War I and II. Urban consolidation policies began to appear in the United States around the same time, with one of the earliest examples being a proposal for the consolidation of railroad lines in Iowa and Minnesota to increase the capacity and efficiency of existing passenger and freight traffic.

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