Duvall council reviews state-mandated ADU changes, debates incentives and infrastructure impacts

Duvall — City planners told the Duvall City Council that state law requires the city to allow accessory dwelling units (ADUs) on lots that allow single-family homes, and staff presented draft local rules and several incentive options for council feedback.

The council heard that under the law the city must allow up to two ADUs per lot in zones that allow single-family homes, permit up to 1,000 square feet by default, allow attached or detached ADUs, and cannot require owner-occupancy. Staff said the city may set some incentives and conditions — for example, allowing a modest increase in ADU size up to 1,200 square feet, reduced rear/side setbacks, and limited impervious-surface increases if approved by the city engineer.

City Community Development Director Thomas said the state timeline requires the city to adopt a compliant ADU program by the statutory deadline and that some technical items — for example how building height is measured — will be addressed in the city’s design guidelines. Thomas also said public works will develop the utility-connection and fee rules separately; staff removed fee-setting and detailed utility language from the draft ADU code so public works could complete technical review.

Council members repeatedly pressed staff on practical implementation details. Council member Schaeffer and others urged that ADU water and sewer services be metered separately and that connection and impact fees be assessed in line with state limits; Thomas said the city intends to require individual meters and noted sewer upgrades could be complex and require physical work in public rights-of-way. Council member Carey and others urged caution about incentives that would permit removal of significant trees or large increases in impervious surface, citing stormwater and tree-preservation goals.

Council discussion also focused on neighborhood character. Some members said incentives should be used carefully because reduced setbacks or tree removal could change privacy and the “feel” of older neighborhoods; others said incentives are needed to produce single-story ADUs and expand housing supply without producing two-story structures that affect views and scale.

Thomas said staff will run focused community outreach (including an ADU segment at the upcoming comprehensive-plan open house), add clearer legal and design language, and return with revised draft code and supporting materials. No final vote was taken; council directed staff to gather public input and to bring back a refined draft for hearing and decision.

Ending — Staff asked council members to submit specific “deal-killers” or high-priority constraints they want reflected in the draft; several council members said they would provide written comments to guide the next draft.