The Sunset City Planning Commission on July 10, 2025 took its first step toward formalizing rules for external accessory dwelling units, or ADUs, saying staff should draft ordinance language, hold a public hearing and that commissioners will research how peer cities regulate lot size, setbacks, parking and fire safety.

Commissioners and staff said the discussion was prompted by a current permit applicant who wants a shop constructed to ADU standards pending a code change. Scott Stevenson, serving as alternate chair, and staff framed the item as either adopting rules that allow external ADUs or adopting a code provision that expressly prohibits them for now so staff can provide a clear answer to applicants.

Why it matters: external ADUs change the housing supply in single-family neighborhoods but raise local concerns about parking, emergency access and neighborhood character. The commission signaled it wants a local framework that adheres to state and building-code requirements while limiting unintended impacts on small lots.

Tyler Seaman, the city building inspector, told the commission the state legislature has “basically… mandated that we have to do some sort of accessory dwelling,” and he said the law and the International Residential Code impose minimum building standards. “A parking consideration is really important,” Seaman added, pointing to winter parking constraints and emergency access as key issues to address in local rules.

Commissioners discussed several technical elements they said must be resolved before drafting final language: minimum lot size or a lot-coverage rule, required off-street parking, a cap on ADU square footage, required setbacks from structures and property lines, limits on building height (single-story vs. two-story), and fire and utility hookups. The commission referenced other Utah cities in the discussion: Clearfield (6,000 sq. ft. cited), West Point (10,000 sq. ft.), Farmington (12,000 sq. ft.) and noted Sunset’s subdivision minimums and R-1/R-3 zoning show differing minimums (subdivision 6,000 sq. ft.; R-1/R-3 8,000 sq. ft.).

Commissioners agreed on several process items: each commissioner will research ordinances from assigned peer cities and add findings to a shared Google document; staff will compile a summary and include the topic on the August agenda; the commission will use an ordinance/public-hearing process if the result is regulatory change; and city staff should loop in utility staff (Jason) to review sewer and water impacts. Staff also said the city could, if desired, adopt an explicit prohibition on external ADUs until an ordinance is enacted so applicants have a clear rule.

Assignments discussed (as recorded): Rodney—West Point and Garden City; Mike—Clearfield/Syracuse or Ogden; Judy—Clinton and Roy; Scott—Salt Lake City and Rich County; others took additional cities to compare (West Haven, Ogden, Clearfield, Syracuse, Cedar City and Washington Terrace among those mentioned). The commission asked staff to circulate a consolidated Google Doc summarizing setbacks, minimum lot sizes, parking requirements, maximum ADU size and any one-ADU-per-lot rules that peer cities use.

The commission emphasized several recurring constraints from earlier internal-ADU work that it wants to carry forward: owner-occupancy conditions reported by staff as required by state direction for internal ADUs, a 30-day minimum restriction for short-term rentals (kept separate in the short-term rental discussion), and a likely cap of one ADU per lot. Commissioners noted the local street and lot patterns mean many Sunset City lots will not be able to accommodate an external ADU under conservative lot-size or setback limits.

Next steps: staff will prepare a draft framework and packet for the August meeting, include utility review from Jason, and the commission will schedule the ordinance for a public hearing if they proceed with rulemaking. The commission did not adopt ordinance text at the meeting; they directed research and asked staff to prepare options.