Bountiful Council approves ordinance changing ADU height and sidewall rules, adds measurement for flat and mansard roofs

The Bountiful City Council on Aug. 26 approved Ordinance 2025-13, rewriting parts of the city’s land-use code to clarify how accessory structures and accessory dwelling units (ADUs) are measured and to allow an enhanced height option for ADUs.

City planner Francisco presented the ordinance and told the council that “an accessory dwelling unit may comply with the following enhanced height and setbacks. And that’s where you find the 25 foot to the peak and then the 20 foot sidewall.” Francisco said the draft reorganizes confusing setback text and places the new height policy in a clearer location in the code.

The ordinance establishes a 25-foot maximum to the peak for permitted ADU height and an enhanced 20-foot sidewall provision. During discussion the council focused on how mansard roofs should be treated: whether to measure them to a 25-foot peak or treat the mansard as a sidewall and limit it to 20 feet under the sidewall measurement rule. Councilwoman Price said she preferred keeping the existing sidewall measurement for mansard and flat roofs and noted, “To me, I don’t see the need to change the language on that.” Several other council members said they were comfortable either way but supported inserting the clarifying sentence to maintain consistency.

Council members instructed staff to reinsert the previously struck language so the code explicitly reads, in two places, “For a flat or mansard roof, the sidewall shall be measured from the average slope of the ground to the highest point of the roof, including any coping, parapet or similar feature.” Francisco indicated the language will be placed in the ADU enhanced-height sections in the permit and conditional-use subsections.

Councilwoman Bradshaw moved to approve the ordinance with the amendments inserting the flat/mansard sidewall measurement in both locations; Councilwoman Child seconded. The council voted in favor; the motion passed.

The ordinance reorganizes existing code language (staff described the reorganization as moving material into clearer numbered subsections) and does not change other setback footprints or conditional-use requirements except to clarify where the enhanced-height option applies. Francisco said the code’s graphic exhibits defining roof forms and height-measurement methods remain in the staff report and in the land-use code references.

What happens next: the ordinance passed with the amendments adopted at the meeting and will be recorded as Ordinance 2025-13. Staff will update the code text to include the restored sidewall-measurement sentence in both the permitted-use and conditional-use ADU sections.

The discussion occurred during the planning and zoning item on the council agenda and included design and measurement clarifications rather than changes to allowable footprints or uses.