ADU rules in Urbana

Urbana has no accessory dwelling unit category at all, so a detached backyard cottage or garage apartment is treated as a second principal structure. Dwellings are principal uses (Section V-2.A) and an accessory use is only 'a use that is incidental to a principal use' (Section II-3), so a second dwelling cannot ride along as an accessory structure. Section V-3.C allows more than one principal structure per lot in any zoning district only 'under conditional use procedures', which means a public hearing before the Zoning Board of Appeals under Section VII-2 and a decision sheet recorded with the Champaign County Recorder. There is no ministerial path and no by-right detached second unit anywhere in the city.

Adding a second unit inside the house, in the basement or as an addition, does not create an ADU in Urbana; it converts the building into a 'Dwelling, Duplex', defined as 'a building containing two dwelling units', because a dwelling unit is any suite with its own kitchen, bathroom and independent entry (Section II-3). That reclassification is what governs: the duplex use does not appear at all in the R-1 district, it is a conditional use requiring Zoning Board of Appeals approval in R-2, and it is permitted by right in R-3 (Single and Two-Family Residential) and in the denser R-4 through R-7 districts. Lot size gates then bite in R-2 and R-3: a lot platted after December 21, 1970 needs at least 9,000 square feet and 80 feet of average width for a duplex, and a lot platted before that date needs at least 6,000 square feet and 60 feet.

Because Urbana never created an ADU category, there is no square footage cap, no percent-of-primary-dwelling rule and no separate height limit written for a second unit. What constrains size instead is the district envelope in Table VI-3, applied to the second dwelling as a principal structure: in R-1 that is a 9,000 square foot minimum lot, 80 feet of average width, 0.30 maximum floor area ratio, 0.50 minimum open space ratio, 35 feet of height, a 25 foot front yard, 5 foot side yards summing to at least 15 feet and a 10 foot rear yard. The accessory structure caps in Section V-2.C.7 (750 square feet on a lot with a single-family home of 1,500 square feet or less, 800 square feet for a two-family home that size, otherwise 1,000 square feet or 50 percent of the dwelling's floor area, whichever is less, plus a 120 square foot cap on sheds) and the 15 foot accessory building height limit in R-1 through R-4 govern garages and sheds only, since an accessory structure houses an accessory use and a dwelling unit is a principal use.

Nothing in the Urbana Zoning Ordinance or City Code conditions a second dwelling, a duplex or any dwelling unit on the owner living on the property, either at application or on an ongoing basis. The only owner-occupancy rule in the code is a use definition, 'Bed and Breakfast, Owner Occupied', which describes overnight rental of rooms and is a separate conditional use. Illinois has no statewide ADU statute, so there is no state preemption at work here either way. The practical caveat is discretion rather than a written rule: because a detached second dwelling runs through a conditional use permit, Section VII-2 lets the Zoning Board of Appeals impose 'such additional conditions as are deemed appropriate or necessary', including minimum lot sizes, increased yards and limits on the intensity of the use, so an individual approval could carry occupancy conditions the ordinance itself does not require.

Table VIII-7 requires 2 off-street spaces for every dwelling unit under 'Single and Two-Family or Similar Uses', so on the ordinance's face a second unit adds two spaces. That local minimum is now preempted across a large share of the city: the Illinois People Over Parking Act, Article 5 of Public Act 104-0457, effective June 1, 2026, says a unit of local government 'may not impose or enforce any minimum automobile parking requirements on a development project if the project is located within one-half mile of a public transportation hub or one-eighth mile of a public transportation corridor', and Section 5-90 makes that an express limitation on home rule. A corridor is a street whose bus service runs at a combined 15 minute or better headway in the peaks, and a hub is an intersection of two or more such routes. Urbana's Zoning Administrator told the Plan Commission on June 18, 2026 that, given the density of Champaign-Urbana Mass Transit District service, those two definitions 'form a substantial area' of Urbana. The city's conforming text amendment (Plan Case 2525-T-26) was carried as Ordinance No. 2026-07-019 on the City Council's July 13, 2026 consent agenda; the compiled Zoning Ordinance posted online still prints the pre-amendment text.

There is no ADU permit in Urbana, so which review applies depends on the form and the district. A detached second dwelling always needs a conditional use permit for more than one principal structure on a lot, heard by the Zoning Board of Appeals with published notice, findings and a decision sheet recorded with the county, and that requirement applies 'in any zoning district'. An internal second unit is instead reviewed as a two-family dwelling: not allowed in R-1, a conditional use before the same board in R-2, and permitted by right (staff-level zoning and building permits) in R-3 and the denser residential districts, subject to the duplex lot area minimums. Conditional use approvals lapse if no building permit or Certificate of Occupancy issues within one year, and a valid written protest raises the approval threshold to two-thirds of the Zoning Board of Appeals.

Urbana writes no ADU-specific rental rule, no minimum lease term and no primary-residence test. Once a second unit exists it can be leased long term, but the Rental Registration and Inspection Program reaches it: Chapter 12.5, Article III applies to 'any dwelling unit and its accessory units that are leased as rental units', makes it unlawful to lease without registering with the building official, and expires the registration every October 14, with inspections and a two-tier fee schedule for single-family dwellings and duplexes. Short-term rental is the harder question because Urbana has no short-term rental ordinance or license at all; transient lodging is controlled purely through zoning use categories. 'Bed and Breakfast, Owner Occupied', an owner-occupied single-family dwelling where rooms are rented to transient guests, is a conditional use in R-1, R-2 and R-3, while a 'Bed and Breakfast Inn' and 'Hotel or Motel' are not listed for those districts at all, so renting an entire second unit to transient guests in a single-family neighborhood has no permitted use category to sit in. Separate sale is not available either: both units share one zoning lot unless a common-lot-line subdivision is approved under Section V-9 and Section VI-3.