Tumwater planning staff previews sweeping development-code updates to comply with new state middle-housing and ADU rules

Erica (planning staff) told the Planning Commission the primary focus of the update is to implement state-required amendments tied to recent housing legislation, which staff cited in the packet as "Senate Bill 55 58." "Senate Bill 55 58 removed the option to adopt our middle housing, our ADUs, our design review development code standard, 6 months after the periodic update," Erica said, and explained that the city must now have specific code language by the time of comprehensive-plan adoption.

The commission was given an overview of subjects staff will amend across Title 18 (zoning) and Title 17 (land division). Staff summarized key requirements as they understand them: allow at least two units per lot in residential zones (with a four-unit minimum in some cases when at least one unit is affordable), permit at least two ADUs per lot, permit a 1,000-square-foot ADU where the code previously limited ADU size to 800 square feet, and limit design-review and other standards so they are not more stringent for middle housing than for single-family homes. Staff also outlined new parking guidelines tied to lot size and reminded commissioners that common-interest instruments such as homeowner association covenants cannot be used prospectively to bar uses that state law requires be allowed going forward.

Commissioners focused on implementation issues. They asked how the rules would affect police and fire service levels, narrow local streets and cumulative traffic where many small infill projects could add vehicles; staff said traffic-study requirements would still apply for larger subdivisions but that cumulative impacts from a large number of individual permits would need monitoring and follow-up in implementation. Commissioners also raised utility and billing questions when multiple ownership structures or later lot splits would share an existing sewer or water connection. Staff said separate service lines increase capital costs and that the city must create clear permitting and connection processes before widespread adoption of lot splits or separate ownership of ADUs.

Religious-organization exemptions and long-term affordability were also discussed. Commissioners asked whether the statutes quoted in the packet limit incentives or special provisions to religious organizations only; staff said the language is state-level and that certain provisions in the RCWs attach long-term affordability requirements (staff cited the packet reference to an RCW notation in the presentation). Staff indicated they will research the statute's details and return with clarifications and proposed code language.

Staff described the city's proposed list of allowed middle-housing types (duplexes, triplexes, fourplexes, townhouses/row houses, stacked flats and cottage housing) and said consultants had performed a gap analysis for design standards. Staff recommended keeping the residential resource zone unchanged because it protects critical environmental areas. The presentation also noted that associations and covenants created under older approvals remain effective; the new rules apply to future approvals and new HOAs.

Procedure and schedule: staff said internal work-group drafting will continue through July and August, with ordinance language to be briefed to the commission in September and returned to council for adoption processes thereafter. Erica said draft ordinance language will be longer and distributed for review because the update will modify multiple portions of the code.

Commissioners requested additional materials in future drafts: clearer mapped zones and nomenclature, an explicit list of code sections to change, an implementation checklist addressing police/fire/transportation impacts, and language clarifying how religious-organization provisions apply. Erica and other staff agreed those items would be part of the next package.

Clarifying details from the presentation: staff said the city intends to allow six middle-housing types (duplexes, triplexes, fourplexes, townhouses/row houses, stacked flats, cottage housing); require ADU allowance of up to two ADUs per lot; must permit a 1,000-square-foot ADU (the municipal code cannot set a maximum lower than that), allow conversion of nonconforming structures into ADUs if they meet building code, and review impact fees so ADU impact fees are capped at 50% of single-family fees. Staff noted new parking thresholds tied to lot size (one space for lots under 6,000 sq. ft., two spaces for larger lots was discussed as a part of the packet summary). The residential resource zone (RSR) is proposed to remain limited to protect wetlands and groundwater.

Speakers and attribution: direct quotations in this article are attributed to Erica (Planning staff), the presenter recorded in the meeting packet. Other substantive comments, questions and clarifications are attributed to named commissioners in the transcript where recorded (Commissioners Robbins, Nelson, Kotek and Kirkpatrick) or summarized as staff responses where a direct quote was not recorded.

Next steps: staff will prepare draft ordinance text, return with a clearly mapped proposal and an implementation action list (including public-safety and utility follow-up) in September and will identify funding or resource requests needed to implement changes.