Hooper City staff propose larger limits for accessory structures and ADUs; council approves drafting ordinance

Hooper City planning staff presented recommended changes to local rules on oversized accessory structures and accessory dwelling units (ADUs) at a Sept. 18 council work meeting, and the council approved a motion to have an ordinance drafted for consideration at a future meeting.

Planning staff summarized sizes the city has recently seen and said the planning commission recommended raising allowed accessory-structure sizes so more projects could be approved administratively rather than repeatedly needing conditional-use review. “The recommendation was to make the changes to be this size,” planning staff member Malcolm said, describing proposed new maximums.

The proposed adjustments would increase maximum accessory-structure sizes in multiple residential zones as presented by staff: R-2 up to 2,500 square feet, R-3/4 up to 3,000 square feet, and R-1 up to 5,000 square feet. Staff told the council the intent is to reduce the number of conditional-use applications and allow staff-level approval for structures that meet the revised limits and other code requirements.

Nut graf: The changes under consideration would alter how Hooper calculates accessory space and ADU living area, and could make larger shops or detached buildings easier to build without a conditional-use hearing. Council members and staff discussed related requirements—off-street parking, foundation standards, impervious-surface limits, and proof-of-occupancy procedures—that would remain in force or be clarified in any ordinance.

Details and discussion

Planning staff explained the ADU change being considered would let an ADU’s living area increase from the current 960 square feet to up to half of the allowed accessory-structure size for the lot. Staff said that would “incentivize” more ADU construction and help the city document and promote ADUs as part of its housing strategy. The working example used by staff: if an R-1 accessory-structure maximum were set at 5,000 square feet, an ADU could have living space up to 2,500 square feet under the “50% of accessory structure” approach unless capped by the city in the ordinance.

Council members and staff discussed exceptions and limits for very small lots. Staff said lots that previously were limited to a 960-square-foot ADU recommendation would likely remain at that smaller cap if they cannot meet other criteria. Council members also asked that the draft clarify whether an ADU could legally be larger than the primary residence; staff said that while unusual, that configuration could occur and that council should decide whether to prohibit it or allow conditional-use review for larger proposals.

Foundation and building standards

A council member raised concerns about wheeled or temporary dwellings being used as ADUs. Council members asked for a requirement that ADUs be on permanent foundations meeting state code. Staff agreed to include language requiring a permanent foundation consistent with building- and state-code requirements. Nate Tolman, who reviews permits, was referenced as the staff member who would verify foundation and impervious-surface compliance at permitting.

Parking, impervious surface and conditional-use review

Council members pressed for clearer parking rules tied to ADU size. Council members noted the city’s existing duplex code requires a two-car garage for each dwelling unit; staff said that requirement has been applied to duplexes and that the ADU table could similarly include a square-foot threshold that would raise parking requirements (for example, one parking space up to a threshold, two above it). Staff also confirmed the city’s current impervious-surface limit would not change with these accessory-structure amendments: impervious coverage would still be checked and enforced at building permit review.

Occupancy verification and enforcement

The draft language discussed includes a requirement that proof of occupancy be provided to the city; staff said the city currently has no standard form and suggested options such as a free annual business-license-style form or random spot checks. Council members suggested a compliance process—such as an annual notice to property owners, a free renewal window, and a late fee—to encourage reporting without immediate criminal penalties.

Next steps and council action

Council Member Ryan D. Wilcox moved and Council Member Hill seconded a motion to authorize staff to draft an amendment to HCC 10-2b-6 (oversized structures) reflecting the planning commission recommendations and the council’s feedback. The motion passed. Staff said the ordinance draft will be returned to council for review and the city attorney will prepare final ordinance language before the next regular meeting.

Ending

Council members asked staff to return with specific draft language addressing foundation standards, a parking schedule tied to ADU size, occupancy-verification procedures and limits for the smallest lots. Staff said they will prepare a draft ordinance and bring it back for a formal vote at a future meeting.