Seattle’s reduced parking minimums cut 18,000 stalls and saved over $500 million

Seattle skyline

By Eric Sundquist

As exemplified by SSTI’s guide to reducing VMT in land use development, modern practice around off-street parking has swung from a more-is-better approach to less-is-more. Among other problems, excess off-street parking tends to raise rents, spread out land uses, and generate traffic.

The question remains: How can policy achieve lower-parking goals? An obvious place to start, as many localities have, is to reduce or eliminate traditional minimum requirements for off-street parking. Such changes, however, may not have much effect if other factors continue to push developers to provide a lot of parking. One common claim, for example, is that lenders will not finance buildings that are short on parking. (Author’s note: As a Plan Commission member in Madison, WI, I hear this claim repeatedly, despite the fact that there are many zero- or low-parking buildings in our city that somehow got financing.)

A recent paper by C.J. Gabbe of Santa Clara University and colleagues suggests that reducing parking minimums is indeed an important policy lever.

The paper reviews 60,361 multifamily housing units built in Seattle in the five years after 2012, when the city eliminated or relaxed parking minimums in large parts of the city while leaving them intact in other parts. Their regression models employ a variety of potentially explanatory variables for parking supply and find that parking minimums are the most important of those variables.

About a third of the buildings provided only the number of parking stalls required by the new minimums, and many others provided more than the new requirement but less than the old one. Comparing parking capacity in the post-2012 buildings to what would have been required to meet pre-2012 minimums, the authors calculate that the city ended up with 17,886 fewer off-site parking stalls than it would have under the old rules, a 31 percent decrease.

Based on costs of providing parking in Seattle, the authors estimate the reduction in parking capacity saved some $537 million. The savings, they write, “likely benefited both housing developers and consumers. Reducing parking requirements allowed developers to forego some construction costs, along with the opportunity cost of using valuable urban land for parking, rather than housing or commercial uses.”

The paper did not get into travel behavior effects. But the lower parking supply, coupled with the city’s requirements that parking be unbundled from rent, should help reduce the high costs of free parking.

Photo credit: Edmund Tse