Seattle can finally move forward on legislation hoped ease the city’s housing crunch by encouraging more mother-in-law apartments and backyard cottages.

The Seattle Hearing Examiner has upheld the city’s environmental analysis on accessory dwelling units is adequate, which clears the way for the City Council to act this summer on relaxing rules on the developments.

“Seattle faces an affordability and housing crisis, and we are acting to increase the supply of housing options as quickly as possible,” Mayor Durkan said. “We need to use every tool in our toolbox to boost the supply of housing – and that includes knocking down barriers for homeowners to build more backyard cottages and in-law units. We must address the significant financial barriers and lengthy, complicated permitting process for backyard cottages in Seattle.”

The council has been working to shape the legislation over the course of years including several rounds of community feedback.

The “detached accessory dwelling units” — or DADUs — have been praised by proponents as a way to add modest density in desirable, family-friendly single-family neighborhoods, increase access to said neighborhoods as well as provide an income stream for single family homeowners who construct and rent out DADUs to tenants.

Seattle has limited the growth of ADUs for the past decade or so. The units were common in Seattle up until the 1950s when both were banned throughout the city. In the ’90s, concerns about insufficient affordable housing stock led local lawmakers to reintroduce ADUs. It wasn’t until 2006 when the council passed an ordinance allowing single family homeowners in the southeast to build DADUs as a pilot project that backyard cottages were reintroduced. Four years later, in 2010, the council allowed for DADU construction citywide.

Backyard cottages were still highly controlled in the years following the citywide expansion, however, and concerns about over-regulation stifling DADU construction prompted the city council to look into code changes back in 2014. A DPD report (PDF) published the following year revealed that only 200 DADUs had been permitted or constructed despite widespread availability of single family lots eligible for DADUs (around the 60 percent of all single family lots in the city), and identified regulatory restrictions on DADU height, lot area coverage, and requirements like having (or building) one off-street parking space for a new DADU and the owner occupancy requirement—which mandates that the owner of a DADU either live in the cottage or in the adjacent single family home—as the main culprits behind low figure. Solicited public input from DADU owners (and potential owners) and designers revealed similar sentiments.

The new legislation has been in motion long enough that council member Mike O’Brien will take it up again under his Sustainability and Transportation Committee — he no longer chairs the planning committee he did when he first took up the issue. The council will hold a special meeting on Wednesday, May 29 for a briefing and discussion on the proposed legislation and another public hearing June 11.

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