ADU rules in Cedar Rapids

Cedar Rapids allows a detached ADU (a garage apartment or standalone backyard structure) by right as an accessory use in every agricultural, residential, mixed-use, urban and traditional district plus I-LI and T-IM; it is not listed in I-GI, I-SW or the P- public districts, which are not single-family districts. The ADU must sit on a lot with a single unit detached or attached dwelling, and the code allows one detached ADU plus one attached or internal ADU on the same lot, which is more permissive than the state floor of one. An existing accessory structure that does not meet dwelling height or setback rules may still be converted as long as the nonconformity is not increased.

Attached ADUs (an addition that expands the house's footprint) and internal ADUs (a basement, attic or side-by-side unit wholly inside the existing house) are both permitted by right in the same districts as detached units. Ord. 004-26 (adopted 2-24-2026) deleted the former rule allowing only one entrance on each street-facing facade of an attached or internal ADU, citing compliance with Senate File 592. One attached or internal ADU may be combined with one detached ADU on the same lot.

Section 32.03.04.C.1.d now mirrors the state floor: an ADU 'may not exceed 1,000 square feet or 50% of the gross floor area of the single-family residence, whichever is greater', with gross floor area excluding attached garages, exterior-only storage, and uncovered porches or decks. Ord. 004-26 replaced the old cap (the primary structure's footprint or 1,000 sq ft, whichever was less, with design-adjustment escapes). ADUs are otherwise held to the zone district's lot and bulk rules for a structure (height, setbacks, coverage) and do not count toward density; the state act bars any of those from being stricter than for the house. Since 7-1-2026 SF 2369 also excludes unfinished basements from the size calculation, which the city text does not yet say.

Neither the current ADU standards in §32.03.04.C.1 nor the Chapter 32 definitions require the owner to live on the property, and the state act forbids any requirement that the property owner be a resident. The city's ADU handout describes ADUs as usable by family or 'leased as an affordable option for unrelated renters'.

Ord. 004-26 struck the ADU use standard 'One parking space is require for each accessory dwelling unit', and the staff memo for the ordinance lists 'Removal of ADU parking requirement' as part of compliance with Senate File 592. However, the ordinance did not amend Table 32.04.02-3 (General Parking Context), and the compiled code effective 2-28-2026 still lists 'Dwelling, Accessory (ADU): 1 per ADU'. Iowa Code §364.3(23)(b)(3) bars a city from requiring 'additional parking beyond that required for a single family residence', and (d) voids conflicting city text, so the table row is unenforceable; the house itself still needs its 2 spaces in the general context.

ADUs are a /P/ (permitted by right) accessory use in Table 32.03-3, not a conditional use, so approval is administrative: a zoning clearance permit reviewed by Development Services for conformance with the code (§32.05.14), plus building and trade permits. The city's handout describes the sequence as a change-of-use application with a site plan, then building permits. The state act requires approval without discretionary review or hearing, on the single-family timeline.

Any unit occupied by someone other than the owner, 'whether by day, week, month, year or any other term, regardless of monetary exchange', is a rental unit that must be registered, and the landlord must hold a Landlord Business Permit (which requires rental business training and inspections); the city's handout puts the fees at $50 for the permit and $38 a year to register a single-family structure. The zoning code defines residential use as tenancy of at least 30 days and classes shorter stays as Visitor Accommodations (bed and breakfast homes are conditional in several districts), but Iowa Code §414.1(1)(e) makes a short-term rental a residential land use and bars city regulations or conditional use permits specific to short-term rentals, so that classification cannot be enforced against an ADU used for short stays. The city's general rental registration still applies. No separate-sale ban appears in the current code.