Bills › 91st General Assembly

HF 947Withdrawn · SF 592 became law instead · April 8, 2025

Relating to county and city regulation of accessory dwelling units

Sponsored by the House Local Government Committee

Topics:Housing & propertyCities & counties

Same legislation: HSB 162, SSB 1182, SF 592

Where it is now

  1. Done: IntroducedFebruary 12, 2025
  2. Done: SubcommitteeFebruary 12, 2025
  3. Done: House committeeMarch 5, 2025
  4. Done: Passes the HouseApril 8, 202589–7
  5. Skipped: Senate committeeSkipped
  6. Done: Passes the SenateMarch 25, 202549–0
  7. Done: To the GovernorMay 1, 2025
  8. Done: Signed into lawMay 1, 2025

SF 592 became law → The same legislation passed as SF 592, so this version was set aside. Go to SF 592 What’s a funnel?

What’s in it

AI summary Cities and counties must allow at least one small extra home, called an accessory dwelling unit, to be built on the same lot as a single-family house. These extra homes cannot be larger than 1,000 square feet or half the size of the main house. Local governments are prevented from using certain rules to block these units, such as requiring specific family relationships between residents or demanding extra parking.1

Read the official explanation

This bill provides that a county or city shall allow a minimum of one accessory dwelling unit (ADU) on the same lot as a single family residence.1, limits or prohibits the construction or use of an ADU. The imposition of an ordinance, motion, resolution, or amendment regulating ADUs that is more restrictive when applied to a common interest community than when applied to a single family residence is prohibited.26.1, subsection 1, paragraph “e”, for cities; and Code chapter 562A; a requirement that the lot containing a single family residence and an ADU have additional parking beyond that required for a single family residence or payment of a fee in lieu of providing additional parking; the requirement of new or separate utility lines between the ADU and public or private utility service connections; imposition of a different county or city impact fee structure for an ADU than the one used for the single family residence on the same lot; and the requirement of improvements or repairs to public streets or sidewalks beyond those imposed on the single family residence on the same lot. A county or city cannot impose restrictions on the occupants of either the single family residence or the ADU by any the following manners: requiring the property owner to be a resident; requiring a familial, marital, or employment relationship to exist between the occupants of the single family residence and the occupants of the ADU; and restricting the occupancy of an ADU based on income or age. A county or city shall not require an ADU to match the exterior design, roof pitch, or finishing materials of the single family residence. If full utility access that includes a separate metering system for billing purposes cannot be provided to the ADU then the county or city can require new or separate utility lines between the ADU and public utility service connections. A county or city must approve an ADU permit application that meets the necessary requirements without discretionary review or hearing and consistent with the time frame assigned to the approval of a single family residence. An ADU permit application shall not have a review timeline or schedule in excess of the county or city’s normal review schedule for a single family residence. If the county or city denies an ADU permit, the reason for denial must be provided in writing to the applicant and include any remedy necessary to secure approval. A county or city ordinance, motion, resolution, or amendment regulating ADUs in a manner that conflicts with the bill is void. A county or city can adopt an ordinance, motion, resolution, or amendment that is more permissive than the requirements provided in the bill. For the purposes of the bill, “accessory dwelling unit” means an additional residential dwelling unit located on the same lot as a single family residence that is either attached to or detached from the single family residence; “detached” includes being part of any accessory structure such as a detached garage; “dwelling unit” means a structure or the part of a structure that is used as a home, residence, or sleeping place; and “single family residence” means a structure maintained and used as a single dwelling unit, even if the structure shares utility lines with the ADU if full utility access that includes a separate metering system for billing purposes is provided to the ADU.

Why it matters. Cities and counties must allow at least one accessory dwelling unit on the same lot as a single-family home, provided the unit meets building regulations and does not exceed 1,000 square feet or a certain percentage of the main house. Local governments are prohibited from imposing certain restrictions on these units, such as specific occupancy requirements, additional parking mandates, or more restrictive design and utility rules than those applied to the primary residence. Property owners using manufactured or mobile homes as these units must place them on permanent foundations and have them assessed for real estate taxes.2

Full bill text · What changed before it passed3

House subcommittee

Named February 12, 2025 (as HSB 162). On February 26, 2025 it recommended amendment and passage.

Three legislators hear a bill first and recommend what the committee should do; it’s the best time to weigh in. How to take part

4 written public comments to its subcommittee: February 27, 2025 (1), February 26, 2025 (2), February 18, 2025 (1) · on the Legislature’s site

Iowa Code it changes

Amends§331.301§364.3

How the Code works4

Lobbying

21 for · 0 against · 17 undecided · Who →

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