Oregon did it in 2019. California followed suit in 2021.
Now, lawmakers in Washington state are reviving a push to legalize multifamily housing statewide, which projections say could allow for hundreds of thousands more homes in the central Puget Sound region alone.
Gov. Jay Inslee announced his support for statewide policy to overturn local bans on so-called "missing middle" housing on Wednesday, effectively banning single-family zoning. It was part of a slate of housing policies he wants the legislature to pursue in the upcoming session, which includes $800 million in investments in permanent supportive housing, tiny homes, hotel conversions, and behavioral health facilities.
"Our housing simply is not keeping pace with the population of the state of Washington," Inslee told a crowd outside of an Habitat for Humanity construction site in Seattle on Wednesday. "If we don't address this fundamental problem, we're not going to be able to really help people stay out of homelessness, because rents will continue to skyrocket."
Single-family zoning laws restrict the number of homes that can be built on a given lot to one, limiting the amount of housing that can be built without eating up more land. Critics say they artificially restrict the supply of housing and encourage wasteful suburban sprawl.
A study from the organization Up for Growth estimated that housing production in Washington lagged 225,000 units behind population growth from 2000 to 2015.
Inslee's proposal, which would allow up to four units on each lot in large and medium-size cities, could allow for more than double that amount of housing to be built in King, Pierce, Snohomish, and Kitsap counties alone, according to an analysis from the University of Washington.
Rep. Jessica Bateman (D-Olympia) and Senator Mona Das (D-Kent) plan to introduce bills in the House and Senate, respectively, that would effectively end single-family zoning across much of the state.
Inslee's support may signal a growing belief that more ambitious efforts are needed to tackle soaring housing costs in a state where legislators have traditionally opted for incentives over mandates, and local governments have found to retain control over their zoning codes.
The city of Olympia effectively ended single-family zoning last year, allowing up to four units on lots across much of the city. A previous attempt at zoning code reform by the city was reversed by a state Growth Management Hearings Board in 2019, prompting legislators to pass a bill making it harder to appeal such reform efforts.
The strategy with that bill, HB 1923, and others has been to nudge cities towards loosening their zoning laws by giving them multiple options for incremental steps to take and grant funding to pursue those ideas. Even those efforts have sometimes failed.
Bateman's bill would require cities with more than 25,000 residents to allow duplexes, triplexes, and quadplexes on all lots and up to sixplexes on lots within 0.5 miles of a major transit stop. Cities with more than 10,000 residents would have to legalize duplexes on all lots, and smaller cities would be offered incentives, but not required, to legalize duplexes.
Bateman's new bill would allocate $3.5 million for the Department of Commerce to provide technical assistance to cities, which could be given extensions on re-writing their codes if the Department of Commerce judges there would be inadequate water, sewer, or transit services in specific neighborhoods.
Cities would be allowed some discretion in how they implement the new housing types by creating siting and design regulations so long as they do not contain "unreasonable" costs or delays.
Das introduced an Oregon-style bill in 2020 that would have allowed duplexes statewide, but it did not pass.