ADU rules in Florence

Florence zones under the Boone County Zoning Regulations, which define an accessory dwelling unit to include one inside a structure accessory to a single-family home. In every ordinary residential district (RS, SR-1, SR-2, SR-3, R-1F, UR-1, UR-2, UR-3) a unit in an accessory structure is a conditional use that needs a permit from the Board of Adjustment after a public hearing, and the lot must be at least 1.5 times the district's minimum lot area. Only the RSE district (and the A-1 and A-2 agricultural districts) list the use as a plain accessory use. The unit is allowed only with a detached single-family home that is not a patio home, one per lot.

An accessory dwelling unit created by partitioning or finishing space inside a detached single-family home (basement, attic or addition) is an accessory use in RSE, RS, SR-1 to SR-3, R-1F and UR-1 to UR-3, needing only a zoning permit. It must use an existing entrance or a new one on the rear or side; a new front or corner-side door is prohibited. Not available with patio homes or in the MHP district.

The ADU may not occupy more than 35 percent of the total floor area of the principal structure, whether it is inside the house or in an accessory building. A unit in an accessory structure is allowed only on a lot at least 1.5 times the minimum lot area of its district. In the SC, WD and GR-R districts the house plus ADU must also stay within the district's maximum density. There is no separate square-foot cap in Section 3114; ordinary accessory-structure setback and height rules still apply.

Section 3114, the only ADU standard, contains no owner-occupancy requirement, and the definitions of accessory dwelling unit and dwelling unit refer only to occupancy by a family. A Board of Adjustment granting a conditional use permit for a detached unit may attach conditions of its own under Section 205.C.

In addition to the parking required for the residence, at least one more parking space must be provided for the accessory dwelling unit. The requirement applies to both internal and accessory-structure units.

An ADU inside the house is an accessory use approved with a zoning permit from the Planning Commission's Zoning Administrator, decided within seven working days. An ADU in an accessory structure is a conditional use in Florence's ordinary residential districts, so it needs a conditional use permit from the Florence Board of Adjustment after a public hearing under KRS 100.237, followed by a zoning permit. In RSE and the agricultural districts both types are accessory uses.

Nothing in the zoning text bars long-term rental of an ADU or separates it from the house for sale; a dwelling unit's occupants must form a housekeeping unit of at least 30 consecutive days. Short-term rentals (under 30 days) are a conditional use in Florence's residential districts, must be at least 1,000 feet from another approved short-term rental, and need a city permit under Ordinance O-20-20 ($500, $1,000,000 liability insurance). Section 3191.B bars short-term rentals in 'any area not considered a primary dwelling (i.e., recreational vehicles, tents, garages, boats, etc.)', which on its face excludes an ADU in a garage or other accessory building; whether an internal ADU qualifies is not settled by the text.