Trenton planners debate accessory-dwelling rules, table application pending lot-line, utility clarifications

Trenton Planning Commission members on Oct. 27 discussed internal accessory dwelling unit (IADU) rules, a pending application that the commission agreed to table until lot-line and accessory-attachment issues are resolved, and next steps for local code changes and enforcement.

A commission member said the application as submitted did not meet state requirements for an internal accessory dwelling unit because the proposed living space and carport/garage arrangement did not fall within the existing footprint and did not share the same utility meter with the primary dwelling. “The state code says internal accessory dwelling units mean it's . . . within the footprint of the primary dwelling,” the member said during the meeting.

The action taken: the commission agreed to table consideration of the application until the property owner submits a lot-line adjustment and clarifies whether the accessory structure can be attached to and treated as part of the primary dwelling. Commissioners also directed staff to send the applicant a letter referencing the relevant state code sections and to identify what must be changed in the submission for it to comply.

Why it matters: state law limits local regulation of internal accessory dwelling units in certain ways — for example, by requiring them to be within the primary dwelling’s footprint, prohibiting separate utility meters, and generally requiring the owner to occupy the primary residence. The commission’s deliberations focused on how those state constraints interact with Trenton’s commercial and residential zoning categories (C1, C2, R1) and on ensuring any local regulation does not conflict with state law.

Discussion and guidance

Commission members reviewed the zoning classification for the parcel in question and noted inconsistent language in the local ordinance. One member read from the ordinance that C2 (a commercial zone) had text implying a two-acre minimum for uses in that chapter. Another member noted the zoning ordinance also contains provisions allowing some residential uses in C1 and said the language appeared contradictory in places.

On utilities and septic: commissioners said the health department is requiring replacement or upgrading of an existing septic system and that the water-meter situation is unresolved for the applicant. One commission member emphasized the practical risk of allowing construction to proceed without clear utility and financing arrangements: “We don’t want them to go through a certain point of foundation and everything and then have it sit there because no bank will [finance it].”

On attachment and appearance: commissioners repeatedly cited the state requirement that an internal ADU must not change the appearance of the primary dwelling as a single-family residence and that it generally must be within the existing footprint. Members discussed whether converting or enclosing a carport, adding a garage, or connecting separate doors or a hallway could meet that standard. They noted that a closed, habitable garage connected by a common wall can count as part of a primary dwelling if the garage is habitable and integrated.

Model codes and next steps

The commission directed staff and members to compile model ADU ordinances from other Utah municipalities for review at a future meeting. Members cited Saratoga Springs and Logan City as examples to examine: Saratoga Springs’ approach emphasizes internal ADUs and stricter definitions of dwelling unit components, while Logan City’s model includes criteria for detached ADUs (location in rear or side yard, prohibition on street-facing entrances, 10 feet behind the front wall plane and size limits expressed as a percentage of the primary dwelling). Commissioners asked staff to email examples and to print copies for the next meeting.

Licensing, enforcement and outreach

Members discussed the town’s current lack of an ADU licensing or regulatory framework and noted several properties with potential noncompliant living arrangements (including campers or accessory structures used as dwelling space). The commission asked staff to begin outreach: a courtesy letter to owners of structures that appear to be used as dwellings, follow-up notification procedures, and a newsletter item directing residents to applications and the town website for required permits and water-meter transfers.

Commissioners stressed the difference between discussion and formal action. Besides tabling the pending application and directing staff to send a compliance letter and compile model ordinances, the meeting produced no change to the town’s code at this session. Staff and members also agreed to review recent state changes to subdivision rules and to propose ordinance edits at a future meeting.

Votes at a glance

- Motion to approve the meeting agenda — approved (procedural) - Motion to approve minutes from prior meeting — approved (procedural)

What’s next

The commission scheduled further work on an ADU chapter and asked members to collect model language and policy examples for the next meeting. Staff was asked to prepare a compliance letter to the applicant referenced in this discussion, to print model ordinance examples for commissioners, and to draft outreach language for the town newsletter on permits and water-meter procedures.