City of Seattle taking pre-approved DADU design submissions

Plans due by Feb. 17; SDCI to make selection in March on backyard cottage options

City of Seattle taking pre-approved DADU design submissions

City of Seattle taking pre-approved DADU design submissions

The City of Seattle has released its submission guide for crafting pre-approved detached accessory dwelling unit designs, the selected plans to eventually be offered to homeowners as a cheaper and quicker option for constructing backyard cottages in single-family lots.

The pre-approved designs are being developed under an executive order made by Mayor Jenny Durkan when she signed legislation the city council approved in July that eases restrictions on developing accessory dwelling units in single-family zones.

Pre-approved designs for backyard cottages are supposed to reduce permitting times and decrease planning costs, incentivizing more DADU construction in Seattle.

The Seattle Department of Construction and Inspections (SDCI) and Office of Planning and Community Development launched an online survey from Sept. 30-Oct. 21 where respondents were asked to rank their preferences for design criteria and describe their neighborhoods.

Eighty-five percent of the 568 respondents were homeowners. Just 8 percent of respondents described their neighborhood as being mostly apartments. Forty-six percent ranked green building as very important, and 48 percent ranked low-cost as very important. Sixty-one percent of respondents reported they were considering constructing a backyard cottage while 32 percent identified as an architect or having a similar profession.

Pre-approved DADU design submissions are due by Feb. 17, and a selection committee will identify 6-10 designs for SDCI staff to pre-approve. Selected designers will then have to submit a permit-ready plan to SDCI to review at no cost. Submit plans to

The city will create an online gallery with images and descriptions of the pre-approved backyard cottage designs. People can find the one they like and be connected with its designer to create a site plan required to complete the permit application. A royalty of up to $1,000 can be set by the designer for use of their plan.

SDCI plans to have pre-approved designs selected by March. The designer retains the copyright to and liability for the pre-approved plan, and will have an hourly rate specified in their plan submission.

DADU categories include: small-footprint (250-300 square feet); family-friendly DADUs with at least two bedrooms; single-story ADUs designed for accessibility; low-cost DADUs; and DADUs with a garage.

Anyone considering submitting a design can learn more at an information session being held 1:30-3:30 p.m. Tuesday, Jan. 14, in Room 4050 of the Seattle Municipal Tower, 700 Fifth Ave.