Bills › 91st General Assembly
Relating to county and city regulation of accessory dwelling units
Sponsored by the Senate Local Government (companion To Hf 2252 By Committee on Local Government) Committee
Where it is now
- Done: IntroducedJanuary 22, 2026
- Done: SubcommitteeJanuary 22, 2026
- Done: Senate committeeFebruary 17, 2026
- Done: Passes the SenateMarch 2, 202644–0
- Skipped: House committeeSkipped
- Done: Passes the HouseMarch 5, 202685–1
- Done: To the GovernorApril 9, 2026
- Done: Signed into lawApril 9, 2026
Signed into law What’s a funnel?
What’s in it
AI summary Local governments must allow at least one small extra house, called an accessory dwelling unit, on lots that already have a single-family home. When calculating how large this extra house can be, cities and counties can no longer include unfinished basements in the measurement. If a person wants to build one in a historic area, officials can only stop them if the new building clearly clashes with the history or look of that neighborhood.1
Read the official explanation
Under current law, a county or city shall allow a minimum of one accessory dwelling unit (ADU) on the same lot as a single family residence in accordance with certain conditions. This bill specifies that a county or city shall allow a minimum of one ADU on the same lot as a single family residence within a zoning district where a single family residence is an allowed principal use. Under current law, an ADU shall not exceed 1,000 square feet or 50 percent of the size of the single family residence, whichever is larger. The bill specifies that the size calculation of an ADU shall exclude unfinished basements.43, would prohibit or limit the ADU. The bill strikes this condition.459, shall be regulated only to the extent that the historic preservation commission or city determines that the proposed ADU would be incongruous with the historical, architectural, archaeological, or cultural aspects of the district, and enters into its records the reasons for such determination. The bill defines “size” to mean the gross living area of the primary dwelling unit excluding garages, decks, and unheated porches.
Why it matters. Cities and counties would be required to allow at least one accessory dwelling unit on lots where single-family homes are permitted. This change would allow homeowners to calculate the allowed size of these units by excluding unfinished basements, garages, decks, and unheated porches from the total square footage. Local historic preservation commissions would only be able to regulate these units if they determine the structure is incongruous with the historical or architectural aspects of a designated district.2
Senate subcommittee
Named January 22, 2026 (as SSB 3070). On February 5, 2026 it recommended 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
Iowa Code it changes
Lobbying
12 for · 0 against · 20 undecided · Who →
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91st General Assembly