Senate File 2369 - Enrolled Senate File 2369 AN ACT RELATING TO COUNTY AND CITY REGULATION OF ACCESSORY DWELLING UNITS. BE IT ENACTED BY THE GENERAL ASSEMBLY OF THE STATE OF IOWA: Section 1. Section 331.301, subsection 29, paragraph a, Code 2026, is amended to read as follows: a. A county shall allow a minimum of one accessory dwelling unit on the same lot as a single family residence within a zoning district where a single family residence is an allowed principal use, in accordance with the following conditions: (1) An accessory dwelling unit shall comply with all applicable building regulations as defined in chapter 103A . (2) An accessory dwelling unit shall not exceed one thousand square feet or fifty percent of the size of the single family residence, whichever is larger. The size calculation of an accessory dwelling unit shall exclude unfinished basements. (3) An accessory dwelling unit shall be prohibited or limited only to the extent that a state historic building code restriction, as adopted by a county in accordance with section 103A.43, subsection 3 , a deed restriction , or a rule of a common interest community, as defined in section 499C.1 , limits or prohibits the construction or use of an accessory dwelling unit. The imposition of an ordinance, motion, resolution, or amendment regulating accessory dwelling units that is more restrictive when applied to a common interest community than

Senate File 2369, p. 2 when applied to a single family residence is prohibited. An accessory dwelling unit proposed for a lot within a historic preservation district as defined in section 15.445, subsection 3, shall be regulated only to the extent that the historic preservation commission as defined in section 15.445, subsection 2, determines that the proposed accessory dwelling unit would be incongruous with the historical, architectural, archaeological, or cultural aspects of the district, and enters into its records the reasons for such determination. (4) If a manufactured home as defined in section 435.1, subsection 3 , or a mobile home as defined in section 435.1, subsection 5 , is used as an accessory dwelling unit, the manufactured home or mobile home shall be converted to real property by being placed on a permanent foundation and assessed for real estate taxes pursuant to section 435.26 . Sec. 2. Section 331.301, subsection 29, paragraph e, Code 2026, is amended by adding the following new subparagraph: NEW SUBPARAGRAPH . (5) “Size” means the gross living area of the primary dwelling unit excluding garages, decks, and unheated porches. Sec. 3. Section 364.3, subsection 23, paragraph a, Code 2026, is amended to read as follows: a. A city shall allow a minimum of one accessory dwelling unit on the same lot as a single family residence within a zoning district where a single family residence is an allowed principal use, in accordance with the following conditions: (1) An accessory dwelling unit shall comply with all applicable building regulations as defined in chapter 103A . (2) An accessory dwelling unit shall not exceed one thousand square feet or fifty percent of the size of the single family residence, whichever is larger. The size calculation of an accessory dwelling unit shall exclude unfinished basements. (3) An accessory dwelling unit shall be prohibited or limited only to the extent that a state historic building code restriction, as adopted by a city in accordance with section 103A.43, subsection 3 , a deed restriction , or a rule of a common interest community, as defined in section 499C.1 , limits or prohibits the construction or use of an accessory dwelling unit. The imposition of an ordinance, motion,

Senate File 2369, p. 3 resolution, or amendment regulating accessory dwelling units that is more restrictive when applied to a common interest community than when applied to a single family residence is prohibited. An accessory dwelling unit proposed for a lot within an area designated as an area of historical significance shall be regulated to the extent that the city or commission, pursuant to section 15.459, subsection 3, determines that the proposed accessory dwelling unit would be incongruous with the historical, architectural, archaeological, or cultural aspects of the area, and enters into its records the reasons for such determination. (4) If a manufactured home as defined in section 435.1, subsection 3 , or a mobile home as defined in section 435.1, subsection 5 , is used as an accessory dwelling unit, the manufactured home or mobile home shall be converted to real property by being placed on a permanent foundation and assessed for real estate taxes pursuant to section 435.26 . Sec. 4. Section 364.3, subsection 23, paragraph e, Code 2026, is amended by adding the following new subparagraph: NEW SUBPARAGRAPH . (5) “Size” means the gross living area of the primary dwelling unit excluding garages, decks, and unheated porches. ______________________________ AMY SINCLAIR President of the Senate ______________________________ PAT GRASSLEY Speaker of the House I hereby certify that this bill originated in the Senate and is known as Senate File 2369, Ninety-first General Assembly. ______________________________ W. CHARLES SMITHSON Secretary of the Senate Approved _______________, 2026 ______________________________ KIM REYNOLDS Governor