S.F. 592 Section 1. Section 331.301, Code 2025, is amended by adding 1 the following new subsection: 2 NEW SUBSECTION . 27. a. A county shall allow a minimum of 3 one accessory dwelling unit on the same lot as a single family 4 residence in accordance with the following conditions: 5 (1) An accessory dwelling unit shall comply with all 6 applicable building regulations as defined in chapter 103A. 7 (2) An accessory dwelling unit shall not exceed one thousand 8 square feet or fifty percent of the size of the single family 9 residence, whichever is larger. 10 (3) An accessory dwelling unit shall be prohibited or 11 limited only to the extent that a state historic building code 12 restriction, as adopted by a county in accordance with section 13 103A.43, subsection 3, a deed restriction, or a rule of a 14 common interest community, as defined in section 499C.1, limits 15 or prohibits the construction or use of an accessory dwelling 16 unit. The imposition of an ordinance, motion, resolution, or 17 amendment regulating accessory dwelling units that is more 18 restrictive when applied to a common interest community than 19 when applied to a single family residence is prohibited. 20 (4) If a manufactured home as defined in section 435.1, 21 subsection 3, or a mobile home as defined in section 435.1, 22 subsection 5, is used as an accessory dwelling unit, the 23 manufactured home or mobile home shall be converted to real 24 property by being placed on a permanent foundation and assessed 25 for real estate taxes pursuant to section 435.26. 26 b. Except as otherwise provided in paragraph “a” or by state 27 law, a county shall not impose any of the following limitations 28 or restrictions: 29 (1) Requirements related to the placement or appearance of 30 an accessory dwelling unit that are more restrictive than those 31 imposed on a single family residence including but not limited 32 to the following: maximum building heights; minimum setback 33 requirements; minimum lot sizes; minimum building frontages; 34 maximum lot coverages; density requirements; and aesthetic 35 -1- LSB 1834SV (2) 91 ll/js 1/ 9

S.F. 592 or architectural standards or requirements. Additionally, a 1 county shall not require an accessory dwelling unit to match 2 the exterior design, roof pitch, or finishing materials of the 3 single family residence. 4 (2) Regulations on the use of an accessory dwelling unit as 5 a rental property that are more restrictive than those provided 6 for in subsection 18 of this section and chapter 562A. 7 (3) A requirement that the lot containing a single family 8 residence and an accessory dwelling unit have additional 9 parking beyond that required for a single family residence or 10 payment of a fee in lieu of providing additional parking. 11 (4) Restrictions on the occupancy of either the single 12 family residence or the accessory dwelling unit by any of 13 the following manners: requiring the property owner to be 14 a resident; requiring a familial, marital, or employment 15 relationship to exist between the occupants of the single 16 family residence and the occupants of the accessory dwelling 17 unit; or restricting the occupancy of an accessory dwelling 18 unit based on income or age. 19 (5) The requirement of new or separate utility lines 20 between the accessory dwelling unit and public utility service 21 connections. However, if full utility access that includes 22 a separate metering system for billing purposes cannot be 23 provided to the accessory dwelling unit, then the county can 24 require new or separate utility lines. 25 (6) Imposition of a different county impact fee structure or 26 development standard for an accessory dwelling unit than those 27 used for the single family residence on the same lot. 28 (7) The requirement of improvements or repairs to public 29 streets or sidewalks beyond those imposed on the single family 30 residence on the same lot. 31 c. A county shall approve an accessory dwelling unit permit 32 application that meets the requirements set forth in paragraph 33 “a” and by state law without discretionary review or hearing 34 and consistent with the time frame assigned to the approval of 35 -2- LSB 1834SV (2) 91 ll/js 2/ 9

S.F. 592 a single family residence. An accessory dwelling unit permit 1 application shall not have a review timeline or schedule in 2 excess of a county’s normal review schedule for a single family 3 residence. If the county denies an accessory dwelling unit 4 permit, the reason for denial shall be provided in writing 5 to the applicant and include any remedy necessary to secure 6 approval. 7 d. A county ordinance, motion, resolution, or amendment 8 regulating accessory dwelling units in a manner that conflicts 9 with this subsection is void. Nothing in this subsection 10 prohibits a county from adopting an ordinance, motion, 11 resolution, or amendment that is more permissive than the 12 requirements provided in this subsection. 13 e. For the purposes of this subsection: 14 (1) “Accessory dwelling unit” means an additional 15 residential dwelling unit located on the same lot as a single 16 family residence that is either attached to or detached from 17 the single family residence. 18 (2) “Detached” includes being part of any accessory 19 structure such as a detached garage. 20 (3) “Dwelling unit” means the same as defined in section 21 562A.6, subsection 3. 22 (4) “Single family residence” means the same as defined 23 in section 562A.6, subsection 15, except to the extent that 24 a single family residence may share utility lines with the 25 accessory dwelling unit if full utility access that includes a 26 separate metering system for billing purposes can be provided 27 to the accessory dwelling unit. 28 Sec. 2. Section 364.3, Code 2025, is amended by adding the 29 following new subsection: 30 NEW SUBSECTION . 20. a. A city shall allow a minimum of 31 one accessory dwelling unit on the same lot as a single family 32 residence in accordance with the following conditions: 33 (1) An accessory dwelling unit shall comply with all 34 applicable building regulations as defined in chapter 103A. 35 -3- LSB 1834SV (2) 91 ll/js 3/ 9

S.F. 592 (2) An accessory dwelling unit shall not exceed one thousand 1 square feet or fifty percent of the size of the single family 2 residence, whichever is larger. 3 (3) An accessory dwelling unit shall be prohibited or 4 limited only to the extent that a state historic building code 5 restriction, as adopted by a city in accordance with section 6 103A.43, subsection 3, a deed restriction, or a rule of a 7 common interest community, as defined in section 499C.1, limits 8 or prohibits the construction or use of an accessory dwelling 9 unit. The imposition of an ordinance, motion, resolution, or 10 amendment regulating accessory dwelling units that is more 11 restrictive when applied to a common interest community than 12 when applied to a single family residence is prohibited. 13 (4) If a manufactured home as defined in section 435.1, 14 subsection 3, or a mobile home as defined in section 435.1, 15 subsection 5, is used as an accessory dwelling unit, the 16 manufactured home or mobile home shall be converted to real 17 property by being placed on a permanent foundation and assessed 18 for real estate taxes pursuant to section 435.26. 19 b. Except as otherwise provided in paragraph “a” or by state 20 law, a city shall not impose any of the following limitations 21 or restrictions: 22 (1) Requirements related to the placement or appearance of 23 an accessory dwelling unit that are more restrictive than those 24 imposed on a single family residence including but not limited 25 to the following: maximum building heights; minimum setback 26 requirements; minimum lot sizes; minimum building frontages; 27 maximum lot coverages; density requirements; and aesthetic 28 or architectural standards or requirements. Additionally, a 29 city shall not require an accessory dwelling unit to match the 30 exterior design, roof pitch, or finishing materials of the 31 single family residence. 32 (2) Regulations on the use of an accessory dwelling unit as 33 a rental property that are more restrictive than those provided 34 for in subsections 9 and 16 of this section, section 414.1, 35 -4- LSB 1834SV (2) 91 ll/js 4/ 9

S.F. 592 subsection 1, paragraph “e” , and chapter 562A. 1 (3) A requirement that the lot containing a single family 2 residence and an accessory dwelling unit have additional 3 parking beyond that required for a single-family residence or 4 payment of a fee in lieu of providing additional parking. 5 (4) Restrictions on the occupancy of either the single 6 family residence or the accessory dwelling unit by any of 7 the following manners: requiring the property owner to be 8 a resident; requiring a familial, marital, or employment 9 relationship to exist between the occupants of the single 10 family residence and the occupants of the accessory dwelling 11 unit; or restricting the occupancy of an accessory dwelling 12 unit based on income or age. 13 (5) A requirement of new or separate utility lines between 14 the accessory dwelling unit and public utility service 15 connections. However, if full utility access that includes 16 a separate metering system for billing purposes cannot be 17 provided to the accessory dwelling unit, then the city can 18 require new or separate utility lines. 19 (6) Imposition of a different city impact fee structure or 20 development standard for an accessory dwelling unit than those 21 used for the single family residence on the same lot. 22 (7) The requirement of improvements or repairs to public 23 streets or sidewalks beyond those imposed on the single family 24 residence on the same lot. 25 c. A city shall approve an accessory dwelling unit permit 26 application that meets the requirements set forth in paragraph 27 “a” and by state law without discretionary review or hearing 28 and consistent with the time frame assigned to the approval of 29 a single family residence. An accessory dwelling unit permit 30 application shall not have a review timeline or schedule in 31 excess of a city’s normal review schedule for a single family 32 residence. If the city denies an accessory dwelling unit 33 permit, the reason for denial shall be provided in writing 34 to the applicant and include any remedy necessary to secure 35 -5- LSB 1834SV (2) 91 ll/js 5/ 9

S.F. 592 approval. 1 d. A city ordinance, motion, resolution, or amendment 2 regulating accessory dwelling units in a manner that conflicts 3 with this subsection is void. Nothing in this subsection 4 prohibits a city from adopting an ordinance, motion, 5 resolution, or amendment that is more permissive than the 6 requirements provided in this subsection. 7 e. For the purposes of this subsection: 8 (1) “Accessory dwelling unit” means an additional 9 residential dwelling unit located on the same lot as a single 10 family residence that is either attached to or detached from 11 the single family residence. 12 (2) “Detached” includes being part of an accessory structure 13 such as a detached garage. 14 (3) “Dwelling unit” means the same as defined in section 15 562A.6, subsection 3. 16 (4) “Single family residence” means the same as defined 17 in section 562A.6, subsection 15, except to the extent that 18 a single family residence may share utility lines with the 19 accessory dwelling unit if full utility access that includes a 20 separate metering system for billing purposes can be provided 21 to the accessory dwelling unit. 22 EXPLANATION 23 The inclusion of this explanation does not constitute agreement with 24 the explanation’s substance by the members of the general assembly. 25 This bill provides that a county or city shall allow a 26 minimum of one accessory dwelling unit (ADU) on the same lot 27 as a single family residence. The ADU shall comply with all 28 applicable building regulations as defined in Code chapter 29 103A, must not exceed 1,000 square feet or 50 percent of the 30 size of the single family residence, whichever is larger, and 31 shall be prohibited or limited only to the extent that a state 32 historic building code restriction, as adopted by a county or 33 city in accordance with Code section 103A.43, subsection 3, a 34 deed restriction, or a rule of a common interest community, 35 -6- LSB 1834SV (2) 91 ll/js 6/ 9

S.F. 592 as defined in Code section 499C.1, limits or prohibits the 1 construction or use of an ADU. The imposition of an ordinance, 2 motion, resolution, or amendment regulating ADUs that is more 3 restrictive when applied to a common interest community than 4 when applied to a single family residence is prohibited. 5 If a manufactured home as defined in Code section 435.1, 6 subsection 3, or a mobile home as defined in Code section 7 435.1, subsection 5, is used as an ADU, the manufactured home 8 or mobile home shall be converted to real property by being 9 placed on a permanent foundation and assessed for real estate 10 taxes pursuant to Code section 435.26. 11 A county or city shall not impose any of the following 12 limitations or restrictions: requirements related to the 13 placement or appearance of an ADU that are more restrictive 14 than those imposed on a single family residence including 15 maximum building heights, minimum setback requirements, minimum 16 lot sizes, minimum building frontages, maximum lot coverages, 17 density requirements, and aesthetic or architectural standards 18 or requirements; regulations on the use of an ADU as a rental 19 property that are more restrictive than those provided for 20 in Code section 331.301, subsection 18, for counties, Code 21 section 364.3, subsections 9 and 16, and Code section 414.1, 22 subsection 1, paragraph “e”, for cities; and Code chapter 23 562A; a requirement that the lot containing a single family 24 residence and an ADU have additional parking beyond that 25 required for a single family residence or payment of a fee 26 in lieu of providing additional parking; the requirement of 27 new or separate utility lines between the ADU and public or 28 private utility service connections; imposition of a different 29 county or city impact fee structure for an ADU than the one 30 used for the single family residence on the same lot; and the 31 requirement of improvements or repairs to public streets or 32 sidewalks beyond those imposed on the single family residence 33 on the same lot. 34 A county or city cannot impose restrictions on the occupants 35 -7- LSB 1834SV (2) 91 ll/js 7/ 9

S.F. 592 of either the single family residence or the ADU by any 1 the following manners: requiring the property owner to be 2 a resident; requiring a familial, marital, or employment 3 relationship to exist between the occupants of the single 4 family residence and the occupants of the ADU; and restricting 5 the occupancy of an ADU based on income or age. A county or 6 city shall not require an ADU to match the exterior design, 7 roof pitch, or finishing materials of the single family 8 residence. If full utility access that includes a separate 9 metering system for billing purposes cannot be provided to the 10 ADU then the county or city can require new or separate utility 11 lines between the ADU and public utility service connections. 12 A county or city must approve an ADU permit application 13 that meets the necessary requirements without discretionary 14 review or hearing and consistent with the time frame assigned 15 to the approval of a single family residence. An ADU permit 16 application shall not have a review timeline or schedule in 17 excess of the county or city’s normal review schedule for a 18 single family residence. If the county or city denies an ADU 19 permit, the reason for denial must be provided in writing 20 to the applicant and include any remedy necessary to secure 21 approval. A county or city ordinance, motion, resolution, 22 or amendment regulating ADUs in a manner that conflicts with 23 the bill is void. A county or city can adopt an ordinance, 24 motion, resolution, or amendment that is more permissive than 25 the requirements provided in the bill. 26 For the purposes of the bill, “accessory dwelling unit” 27 means an additional residential dwelling unit located on the 28 same lot as a single family residence that is either attached 29 to or detached from the single family residence; “detached” 30 includes being part of any accessory structure such as a 31 detached garage; “dwelling unit” means a structure or the 32 part of a structure that is used as a home, residence, or 33 sleeping place; and “single family residence” means a structure 34 maintained and used as a single dwelling unit, even if the 35 -8- LSB 1834SV (2) 91 ll/js 8/ 9