In Planetizen

A controversy in planning concerns the degree that upzoning can increase affordability.

I reviewed this issue two years ago in Planetizen columns, The Housing Supply Debate: Evaluating the Evidence, and A Critical Review of 'Sick City: Disease, Race, Inequality and Urban Land', and in a Governing Magazine article, The Housing Affordability Recipe. Recent studies support the conclusion that broadly-applied upzoning that allows more compact housing types (townhouses, multiplexes, and multi-family) in multimodal neighborhoods, with complementary policies such as reducing parking minimums, can increase housing supply, drive down prices, and increase overall affordability.

This research has not prevented skeptics from arguing the opposite; that upzoning increases rather than reduces housing prices and reduces affordability. Such skepticism is understandable: housing prices tend to be higher in dense urban areas and a parcel's value tends to increase if it is upzoned. However, upzoning a large urban area has very different effect: it creates a competitive market for land prezoned for higher density housing which minimizes lane value increases, as discussed in UCLA Professor Shane Phillips' report, Building Up the "Zoning Buffer": Using Broad Upzones to Increase Housing Capacity Without Increasing Land Values.

Sprawl is malfunctioning. It has underperformed for decades, but its collapse has become obvious with the recent mortgage meltdown and economic crisis, and its abundance magnifies the problems of its failure.

Let us be clear that sprawl and suburbia are not synonymous. There are many first-generation suburbs, most of them built before WWII, that function well, primarily because they are compact, walkable, and have a mix of uses. Sprawl, on the other hand, is characterized by auto-dependence and separation of uses. It is typically found in suburban areas, but it also affects the urban parts of our cities and towns.

Sprawl's defects are not limited to economics. Sprawl is central to our inefficient use of land, energy, and water, and to increased air and water pollution, greenhouse gas emissions, and the loss of open space and natural habitats. Because it requires a car to reach every destination, it is also to blame for time wasted in traffic, the exponential increase in new infrastructure costs, and health problems such as obesity. Social problems have also been linked to sprawl's isolation and lack of diversity.