Permits for accessory dwelling units jumped by 250 percent between 2019 and 2022.

Since Seattle started permitting accessory dwelling units (ADUs) in 2019, the city has seen a surge in applications for backyard cottages and other ADUs. According to an article by Daniel Beekman in The Seattle Times, “Almost 1,000 ADUs were permitted last year, up from 280 in 2019.”
That number comes from a report evaluating the success of the city’s ADU policy that could serve as evidence for state legislators, who are considering loosening regulations on ADUs and other mid-density housing types statewide. “House Bill 1337 would remove many barriers to ADUs, while Senate Bill 5235 would also remove some. House Bill 1110 would allow duplexes, fourplexes and sixplexes in more areas.” As Beekman explains, “Proponents of those bills can point to ADUs in Seattle as proof of policy decisions boosting a city’s housing supply with diverse choices in popular areas, while skeptics may question how affordable some of the new choices are — or simply object to density in their neighborhoods.”
Washington needs to add 55,000 housing units in the next two decades to meet demand, and proponents of ADUs say they are an effective and affordable option that maintains low density in neighborhoods while adding housing units and giving homeowners an opportunity to earn extra income.
The report notes that ADUs are being built in almost all parts of Seattle, including single-family zones that are otherwise resistant to new housing. “Many new ADUs are being developed in conjunction with new houses in three-unit packages that resemble town houses, the report notes.”
Not all ADUs become long-term housing, however. “The report estimates that 12% of ADUs in Seattle are currently licensed as short-term rentals like those advertised on Vrbo and Airbnb.”
FULL STORY: Seattle is now building more ADUs than single houses

The End of Single-Family Zoning in Arlington County, Virginia
Arlington County is the latest jurisdiction in the country to effectively end single-family zoning.

‘Train Daddy’ Andy Byford to Oversee Amtrak’s High-Speed Rail Efforts
Byford, who formerly ran NYC Transit and Transport for London, could bring renewed vigor to the agency’s plans to expand regional rail in the United States.

Seattle Bus Lane Cameras Capture Over 100,000 Violations
An automated traffic enforcement pilot program caught drivers illegally using transit lanes more than 110,000 times in less than a year.

Immigration Grows, Population Drops in Many U.S. Counties
International immigration to the country’s most populous areas tripled even as major metropolitan areas continued to lose population.

$616 Million in Development Incentives Approved for District Detroit
The “Transformational Brownfield” incentives approved by the Detroit City Council for the $1.5 billion District Detroit still require approval by the state.

Affordable Housing Development Rejected for Lack of Third Staircase in Connecticut
The New Canaan Planning Commission rejected a development proposal, including 31 below-market-rate apartments, for lack of a third staircase, among other reasons, at a time when advocates are pushing to relax two-staircase requirements.
Houston-Galveston Area Council
City of Malibu
Association of Metropolitan Planning Organizations
HUD's Office of Policy Development and Research
HUD's Office of Policy Development and Research
HUD's Office of Policy Development and Research
City of Spearfish
City of Lomita
Urban Design for Planners 1: Software Tools
This six-course series explores essential urban design concepts using open source software and equips planners with the tools they need to participate fully in the urban design process.
Planning for Universal Design
Learn the tools for implementing Universal Design in planning regulations.