Council passes ADU ordinance

This afternoon, the City Council passed into law an ordinance loosening rules on Accessory Dwelling Units (aka ADUs), often referred to as “backyard cottages” and “mother-in-law apartments.”

The Council adopted three last-minute amendments prior to its adoption:

  • a technical clean-up amendment fixing typos and other drafting errors;
  • an amendment offered by Council member Pacheco that would grant an additional 35 square feet of floor space for bicycle storage;
  • an amendment by Council member O’Brien that would direct the city to study the use of ADUs as short-term rentals (i.e. AirBnB rentals) and state the Council’s intent to restrict such use if it is excessive, so as not to detract from the goal of having ADUs contribute to the long-term rental housing pool.

Council member Herbold took another run at her amendment that would have re-introduced a one-year property ownership requirement before a second ADU could be built on a property. She clarified that this was not an “owner occupied” requirement, but rather an attempt to create a disincentive for real estate speculators. Council members Mosqueda and Sawant countered that there was no evidence that speculators were a problem related to ADUs, and her amendment failed by a 1-7 vote (Harrell was absent today).

The bill also effectively prohibits the building of “McMansions” on most city lots by setting a maximum square footage at 2500 square feet for lots up to 5000 square feet, and 1/2 the lot size above 5000 square feet.

The final, amended bill passed 8-0, and heads to the Mayor’s desk for her signature. It will take effect 30 days after she signs it — which means that there will be a flurry of permit applications for McMansions over the next month.

Over the weekend, the Seattle Times published an editorial accusing the City Council of relying on “ideology and lobbying” instead of data and research in writing the ADU ordinance. That clearly hit a raw nerve with some Council members. Gonzalez and Mosqueda, in particular, made a point of calling it out and then reciting the data and research that they believe supports the bill. Mosqueda even posted a long thread on Twitter on the topic.