How Zoning Changes Could Boost Housing Supply in Seattle

The Urban Institute’s Yonah Freemark, Lydia Lo, Olivia Fiol, Gabe Samuels, and Andrew Trueblood analyzed how changes to Seattle’s zoning code could stimulate more housing production, encourage transit-oriented development, and alleviate the region’s housing shortage.

According to the authors, when it comes to regional transit, “About one third of station-adjacent land is zoned for only single-family homes; almost 50 percent requires at least one parking spot per unit. Both zoning restrictions add to housing costs, making new construction more difficult and new homes more expensive.”

But there is an opportunity for the Puget Sound region, the authors argue. “With housing construction slowing in recent decades, policymakers can implement new land-use policies locally or statewide to accelerate construction, add space for residents, and reduce housing costs.”

The authors highlight key reforms that could help accelerate housing production in Seattle and elsewhere, including: permitting more high-density housing; allowing ‘missing middle’ housing types; and promoting two- to four-unit buildings to gently increase density and provide more housing options. “We also studied a fourth reform—legalizing apartment units on land now zoned only for commercial space—but found that it would have a limited impact on housing overall, because commercial-only zoning is rare in most of the areas near transit in the region.”