Bothell amends code for accessory dwelling units

The city hopes to encourage development of ADUs as an affordable housing option.

The Bothell City Council voted unanimously to approve a few amendments to the city’s accessory dwelling unit (ADU) regulations, hoping to encourage more of these units to be built as part of the city’s affordable housing strategy.

Affordable housing goals and housing choice policies were included in the city’s 2018 Housing Strategy Update and in the Imagine Bothell Comprehensive Plan. The city is also working with A Regional Coalition for Housing (ARCH) on future affordable housing and ADU initiatives.

Senior planner Dave Boyd outlined the amendments, which include allowing development of “carriage house”-type ADUs in limited situations, allowing home occupations in ADUs subject to the same requirements as for primary residences and consolidating regulations for ADUs into a new section of the city code.

The idea is to remove impediments that may have hindered development of ADUs in the past. The amendments will allow ADUs to be built over garages that are located on alleys, and modify height limits to allow for two-story detached ADUs.

“I know that 15 years ago, there were quite a few cities that didn’t allow [ADUs] at all,” Boyd said. “A lot of cities had very restrictive size limitations, as Bothell did.”

He said that the city addressed some of those issues in 2014 when it first allowed detached ADUs and removed some of the size restrictions, though it retained an overall limit of 800 square feet.

“We are doing this partly, and I would say largely, as a way of providing an affordable housing option,” Boyd said. “We want to keep them a relatively small size so that they remain relatively affordable.”

He said that under the city’s code, ADUs couldn’t be placed in rear setbacks and had a 20-foot height limit, which made it difficult to build over a garage or to build any two-story ADUs. He noted that one of the biggest impediments is that Bothell is one of few jurisdictions that charges impact fees for ADUs.

Recommendations from the ARCH effort are expected to include other ADU code amendments, which will be proposed for consideration in the 2019 Planning Docket, according to the council’s agenda bill.

In addition to those recommendations, building and hard surface coverage limits, use of manufactured or modular homes and potential use of pre-approved plans and utility hookups are issues that will be brought back to the council later.

Council members had questions about setbacks, parking, stormwater and the impacts of homeowners’ associations on ADUs, the latter of which Boyd said will be addressed in the ARCH study.

The SEPA review has not been completed for these amendments, so staff asked for preliminary approval, with final adoption after the SEPA review is complete on Oct. 2. They passed 6-0, as council member Rosemary McAuliffe was absent.

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